Network link endpoint capability detection

Abstract

Support for a mixed network environment is provided which can contain multiple isochronous and/or non-isochronous LAN protocols such as isochronous-ethernet, ethernet, isochronous-token ring, token ring, other isochronous-LAN or other LAN systems. Support for a mixed environment includes a protocol detection mechanism which is embodied in a handshaking scheme. This handshaking scheme determines the signalling capability at the end points of the link and implements the correct protocol. This enables isochronous nodes and hubs to automatically detect the presence of ethernet, token ring, or other LAN equipment at the other end of the network cable. If this detection occurs, the isochronous LAN equipment will fall-back to a LAN compliant mode of operation. Typically, only the hub will have the capability of operating in different networking modes, such as ethernet, Token Ring isochronous modes. The hub will listen for some form of identification from the attached nodes as to the type of service to provide—isochronous or non-isochronous; ethernet, token ring or other LAN service.

1. In a data communication network comprising a hub coupled to at least one node, an apparatus for establishing communication between the hub and a node comprising:
 a hub transmitter coupled to the hub for transmitting a hub protocol signal to the node, the hub protocol signal indicating a communication protocol, including a format for a data transmission, with which the hub is capable of communicating;  
 a node receiver coupled to the node for receiving the hub protocol signal;  
 a node transmitter coupled to the node for transmitting a node protocol signal to the hub, the node protocol signal indicating a communication protocol, including a format for a data transmission, with which the node is capable of communicating;  
 wherein the communication protocol indicated by the node protocol signal is different from the communication protocol indicated by the hub protocol signal;  
 a hub receiver coupled to the hub for receiving the node protocol signal;  
 a protocol identifying circuit coupled to the hub receiver for identifying the communication protocol indicated by the node protocol signal from among a plurality of possible communication protocols with which the hub is capable of communicating; and  
 wherein the hub transmitter includes a communication circuit for communicating with the node using the communication protocol indicated by the node protocol signal in response thereto.  
 
     
     
       2. The apparatus according to  claim 1  wherein the hub receiver includes frame receiving circuitry for receiving data formatted in a frame structure, and packet receiving circuitry for receiving data formatted in a packet structure and wherein the received data formatted in the frame structure and the received data formatted in the packet structure are received over the same receiving communication path, and wherein the hub transmitter includes frame transmitting circuitry for transmitting data formatted in the frame structure, and packet transmitting circuitry for transmitting data formatted in the packet structure, wherein the data formatted in the frame structure and the data formatted in the packet structure are transmitted over the same transmitting communication path. 
     
     
       3. The apparatus according to  claim 2  wherein the hub protocol signal comprises a signal indicating a protocol corresponding to data formatted in the frame structure, and wherein the node protocol signal comprises a signal indicating a protocol corresponding to data formatted in the packet structure. 
     
     
       4. The apparatus according to  claim 2  wherein the node protocol signal indicates an ethernet protocol, and wherein the data formatted in the packet structure is formatted according to the ethernet protocol. 
     
     
       5. The apparatus according to  claim 2  wherein the node protocol signal indicates a token-ring protocol, and wherein the data formatted in the packet structure is formatted according to the token-ring protocol. 
     
     
       6. The apparatus according to  claim 2  wherein the frame receiving circuitry includes packet converting circuitry for converting received data formatted in the frame structure into data formatted in a packet structure. 
     
     
       7. The apparatus according to  claim 6  wherein the node protocol signal indicates an ethernet protocol, and wherein the data formatted in the packet structure is formatted according to the ethernet protocol. 
     
     
       8. The apparatus according to  claim 6  wherein the node protocol signal indicates a token-ring protocol, and wherein the data formatted in the packet structure is formatted according to the token-ring protocol. 
     
     
       9. The apparatus according to  claim 1  wherein the hub receiver includes frame receiving circuitry for receiving data formatted in a frame structure, and isochronous receiving circuitry for receiving data formatted in an isochronous structure, wherein the received data formatted in a frame structure and the received data formatted in the isochronous structure are received over the same receiving communication path, and wherein the hub transmitter includes frame transmitting circuitry for transmitting data formatted in a frame structure, and isochronous transmitting circuitry for transmitting data formatted in an isochronous structure, wherein the data formatted in the isochronous structure and the data formatted in the frame structure are transmitted over the same transmitting communication path. 
     
     
       10. The apparatus according to  claim 9  wherein the hub protocol signal comprises a signal indicating a protocol corresponding to data formatted in the frame structure, and wherein the node protocol signal comprises a signal indicating a protocol corresponding to data formatted in the isochronous structure. 
     
     
       11. The apparatus according to  claim 9  wherein the node protocol signal indicates the isochronous protocol, and wherein the data formatted in the isochronous structure is communicated to the node according to the isochronous protocol. 
     
     
       12. The apparatus according to  claim 9  wherein the frame receiving circuitry includes isochronous converting circuitry for converting received data formatted in the frame structure into data formatted in the isochronous structure. 
     
     
       13. The apparatus according to  claim 12  wherein the node protocol signal indicates the isochronous protocol, and wherein the converted data formatted in the isochronous structure is communicated to the node according to the isochronous protocol. 
     
     
       14. The apparatus according to  claim 9  wherein the frame receiving circuitry includes packet converting circuitry for converting received data formatted in the frame structure into data formatted in a packet structure. 
     
     
       15. An apparatus as set forth in  claim 1  wherein said node transmitter transmits said node protocol signal responsive to said node receiver receiving said hub protocol signal. 
     
     
       16. In a data communication network comprising a hub coupled to at least one node, an apparatus for establishing communication between the hub and a node comprising:
 a hub transmitter coupled to the hub for transmitting a hub protocol signal to the node, the hub protocol signal indicating a communication protocol, including a format for a data transmission, with which the hub is capable of communicating;  
 a protocol identifying circuit coupled to the node receiver for identifying the communication protocol indicated by the hub protocol signal from among a plurality of possible communication protocols with which the node is capable of communicating; and  
 a node transmitter coupled to the protocol identifying circuit for transmitting a node protocol signal, including a format for a data transmission, to the hub indicating that communication between the hub and the node will take place with the protocol indicated by the hub protocol signal.  
 
     
     
       17. The apparatus according to  claim 16  wherein the node receiver includes frame receiving circuitry for receiving data formatted in a frame structure, and packet receiving circuitry for receiving data formatted in a packet structure, wherein the received data formatted in the frame structure and the received data formatted in the packet structure are received over the same receiving communication path, and wherein the node transmitter includes frame transmitting circuitry for transmitting data formatted in the frame structure, and packet transmitting circuitry for transmitting data formatted in the packet structure, wherein the data formatted in the frame structure and the data formatted in the packet structure are transmitted over the same transmitting communication path. 
     
     
       18. The apparatus according to  claim 17  wherein the hub protocol signal indicates an ethernet protocol, and wherein the data formatted in the packet structure is formatted according to the ethernet protocol. 
     
     
       19. The apparatus according to  claim 17  wherein the hub protocol signal indicates a token-ring protocol, and wherein the data formatted in the packet structure is formatted according to the token-ring protocol. 
     
     
       20. The apparatus according to  claim 17  wherein the frame receiving circuitry includes packet converting circuitry for converting received data formatted in a frame structure into data formatted in a packet structure. 
     
     
       21. The apparatus according to  claim 16  wherein the node receiver includes frame receiving circuitry for receiving data formatted in a frame structure, and isochronous receiving circuitry for receiving data formatted in an isochronous structure, wherein the received data formatted in the frame structure and the received data formatted in the isochronous structure are received over the same receiving communication path, and wherein the node transmitter includes frame transmitting circuitry for transmitting data formatted in the frame structure, and isochronous transmitting circuitry for transmitting data formatted in the isochronous structure, wherein the data formatted in the frame structure and the data formatted in the isochronous structure are transmitted over the same transmitting communication path. 
     
     
       22. The apparatus according to  claim 21  wherein the hub protocol signal indicates an isochronous protocol, and wherein the transmitted data formatted in the isochronous structure is communicated to the hub according to the isochronous protocol. 
     
     
       23. The apparatus according to  claim 21  wherein the frame receiving circuitry includes isochronous converting circuitry for converting received data formatted in the frame structure into data formatted in the isochronous structure. 
     
     
       24. In a data communication network comprising a hub coupled to at least one node, an apparatus for establishing communication between the hub and a node comprising:
 a hub transmitter coupled to the hub for transmitting a hub protocol signal to the node, the hub protocol signal indicating one of a plurality of communication protocols, including a format for a data transmission, with which the hub is capable of communicating;  
 a node receiver coupled to the node for receiving the hub protocol signal;  
 a first protocol identifying circuit coupled to the node receiver for identifying the communication protocol indicated by the hub protocol signal from among a plurality of communication protocols with which the node is capable of communicating;  
 a node transmitter coupled to the node receiver for transmitting a node protocol signal to the hub, the node protocol signal indicating the communication protocol, including a format for a data transmission, indicated by the hub protocol signal if the communication protocol indicated by the hub protocol signal is a communication protocol with which the node is capable of communicating;  
 a hub receiver coupled to the hub for receiving the node protocol signal;  
 a second protocol identifying circuit coupled to the hub receiver for identifying the communication protocol indicated by the node protocol signal from among a plurality of communication protocols with which the hub is capable of communicating;  
 wherein the hub transmitter includes a communication circuit for communicating with the node using the communication protocol indicated by the node protocol signal in response thereto.  
 
     
     
       25. The apparatus according to  claim 24  wherein said data communication network comprises a plurality of nodes and the data communication network is configured in a star topology. 
     
     
       26. The apparatus according to  claim 24  wherein said data communication network comprises a plurality of hubs wherein the hubs are configured in a ring topology. 
     
     
       27. The apparatus according to  claim 24  wherein said data communication network comprises a plurality of nodes and wherein the nodes are configured in a tree topology. 
     
     
       28. The apparatus according to  claim 24  wherein the hub protocol signal comprises a series of 100 nanosecond pulses occurring at nominal 16 millisecond intervals. 
     
     
       29. The apparatus according to  claim 24  wherein the hub receiver includes frame receiving circuitry for receiving data formatted in a frame structure, and packet receiving circuitry for receiving data formatted in an packet structure, wherein the received data formatted in a frame structure and the received data formatted in the packet structure are received over the same receiving communication path, and wherein the hub transmitter includes frame transmitting circuitry for transmitting data formatted in a frame structure, and packet transmitting circuitry for transmitting data formatted in a packet structure, wherein the transmitted data formatted in the frame structure and the transmitted data formatted in the packet structure are transmitted over the same transmitting communication path. 
     
     
       30. The apparatus according to  claim 29  wherein the hub protocol signal comprises a signal indicating a protocol corresponding to data formatted in the frame structure, and wherein the node protocol signal comprises a signal indicating a protocol corresponding to data formatted in the frame structure. 
     
     
       31. The apparatus according to  claim 29  wherein the hub protocol signal indicates an isochronous-ethernet protocol, and wherein the transmitted data formatted in the frame structure is formatted according to the isochronous-ethernet protocol. 
     
     
       32. The apparatus according to  claim 29  wherein the hub protocol signal indicates an isochronous-token ring protocol, and wherein the transmitted data formatted in the frame structure is formatted according to the isochronous-token ring protocol. 
     
     
       33. The apparatus according to  claim 29  wherein the hub protocol signal indicates an ethernet protocol, and wherein the transmitted data formatted in the packet structure is formatted according to the ethernet protocol. 
     
     
       34. The apparatus according to  claim 29  wherein the hub protocol signal indicates a token-ring protocol, and wherein the transmitted data formatted in the packet structure is formatted according to the token-ring protocol. 
     
     
       35. The apparatus according to  claim 29  wherein the frame receiving circuitry includes packet converting circuitry for converting received data formatted in the frame structure into data formatted in the packet structure. 
     
     
       36. The apparatus according to  claim 35  wherein the hub protocol signal indicates an ethernet protocol, and wherein the transmitted data formatted in the packet structure is formatted according to the ethernet protocol. 
     
     
       37. The apparatus according to  claim 35  wherein the hub protocol signal indicates a token-ring protocol, and wherein the transmitted data formatted in the packet structure is formatted according to the token-ring protocol. 
     
     
       38. The apparatus according to  claim 35  wherein the hub protocol signal indicates an isochronous-ethernet protocol, and wherein the transmitted data formatted in the frame structure is formatted according to the isochronous-ethernet protocol. 
     
     
       39. The apparatus according to  claim 35  wherein the hub protocol signal indicates an isochronous-token ring protocol, and wherein the transmitted data formatted in the frame structure is formatted according to the isochronous-token ring protocol. 
     
     
       40. The apparatus according to  claim 29  wherein the frame receiving circuitry includes isochronous converting circuitry for converting received data formatted in a frame structure into data formatted in an isochronous structure. 
     
     
       41. The apparatus according to  claim 40  wherein the hub protocol signal indicates an isochronous protocol. 
     
     
       42. An apparatus as set forth in  claim 24  wherein said node transmitter transmits said node protocol signal responsive to said node receiver receiving said hub protocol signal. 
     
     
       43. The apparatus according to  claim 24  wherein the hub receiver includes frame receiving circuitry for receiving data formatted in a frame structure, and isochronous receiving circuitry for receiving data formatted in an isochronous structure, wherein the received data formatted in a frame structure and the received data formatted in the isochronous structure are received over the same receiving communication path, and wherein the hub transmitter includes frame transmitting circuitry for transmitting data formatted in a frame structure, and isochronous transmitting circuitry for transmitting data formatted in an isochronous structure, wherein the transmitted data formatted in the frame structure and the transmitted data formatted in the isochronous structure are transmitted over the same transmitting communication path. 
     
     
       44. The apparatus according to  claim 43  wherein the hub protocol signal indicates an isochronous protocol. 
     
     
       45. The apparatus according to  claim 43  wherein the hub protocol signal indicates an isochronous-ethernet protocol, and wherein the transmitted data formatted in the frame structure is formatted according to the isochronous-ethernet protocol. 
     
     
       46. The apparatus according to  claim 43  wherein the hub protocol signal indicates an isochronous-token ring protocol, and wherein the transmitted data formatted in the frame structure is formatted according to the isochronous-token ring protocol. 
     
     
       47. The apparatus according to  claim 43  wherein the frame receiving circuitry includes isochronous converting circuitry for converting received data formatted in a frame structure into data formatted in an isochronous structure. 
     
     
       48. The apparatus according to  claim 47  wherein the hub protocol signal indicates an isochronous protocol. 
     
     
       49. The apparatus according to claim  48    47  wherein the hub protocol signal indicates an isochronous-ethernet protocol, and wherein the transmitted data formatted in the frame structure is formatted according to the isochronous-ethernet protocol. 
     
     
       50. The apparatus according to  claim 47  wherein the hub protocol signal indicates an isochronous-token ring protocol, and wherein the transmitted data formatted in the frame structure is formatted according to the isochronous-token ring protocol. 
     
     
       51. The apparatus according to  claim 47  wherein the frame receiving circuitry includes packet converting circuitry for converting received data formatted in a frame structure into data formatted in a packet structure. 
     
     
       52. The apparatus according to  claim 51  wherein the hub protocol signal indicates an ethernet protocol, and wherein the transmitted data formatted in the packet structure is formatted according to the ethernet protocol. 
     
     
       53. The apparatus according to  claim 51  wherein the hub protocol signal indicates a token-ring protocol, and wherein the transmitted data formatted in the packet structure is formatted according to the token-ring protocol. 
     
     
       54. The apparatus according to  claim 51  wherein the hub protocol signal indicates an isochronous-ethernet protocol, and wherein the transmitted data formatted in the frame structure is formatted according to the isochronous-ethernet protocol. 
     
     
       55. The apparatus according to  claim 51  wherein the hub protocol signal indicates an isochronous-token ring protocol, and wherein the transmitted data formatted in the frame structure is formatted according to the isochronous-token ring protocol. 
     
     
       56. The apparatus according to  claim 51  wherein the hub protocol signal indicates an isochronous protocol. 
     
     
       57. In a data communication network comprising at least first and second communication endpoints, an apparatus for establishing communication between the first and second endpoints comprising:
 a first endpoint transmitter coupled to the first endpoint for transmitting a first endpoint protocol signal to the second endpoint, the first endpoint protocol signal indicating a communication protocol, including a format for data transmission, with which the first endpoint is capable of communicating;  
 a second endpoint receiver coupled to the second endpoint for receiving the first endpoint protocol signal;  
 a second endpoint transmitter coupled to the second endpoint receiver for transmitting a second endpoint protocol signal to the first endpoint, the second endpoint protocol signal indicating a communication protocol, including a format for data transmission with which the second endpoint is capable of communicating;  
 a first endpoint receiver coupled to the first endpoint for receiving the second endpoint protocol signal;  
 a protocol identifying circuit coupled to the first endpoint receiver for identifying the communication protocol indicated by the second endpoint protocol signal from among a plurality of possible communication protocols with which the first endpoint is capable of communicating; and  
 a communication circuit in said first endpoint transmitter responsive to said protocol identifying circuit for communicating with the second endpoint using the communication protocol indicated by the second endpoint protocol signal.  
 
     
     
       58. The apparatus according to  claim 57  wherein the communication circuit includes a first receiver sub-circuit in said first endpoint receiver and a first transmitter sub-circuit in said first endpoint transmitter for communicating using a first communication protocol and a second receiver sub-circuit in said first endpoint receiver and a second transmitter sub-circuit in said first endpoint transmitter for communicating using a second communication protocol, and wherein said communication circuit communicates with said second endpoint using one of said first receiver and transmitter sub-circuits and said second receiver and transmitter sub-circuits responsive to said second endpoint protocol signal. 
     
     
       59. The apparatus according to  claim 58  wherein the first sub-circuit includes frame receiving circuitry for receiving data formatted in a frame structure, and the second sub-circuit includes packet receiving circuitry for receiving data formatted in a packet structure and wherein the received data formatted in the frame structure and the received data formatted in the packet structure are received over the same receiving communication path, and wherein the first sub-circuit further includes frame transmitting circuitry for transmitting data formatted in the frame structure, and the second sub-circuit includes packet transmitting circuitry for transmitting data formatted in the packet structure, wherein the data formatted in the frame structure and the data formatted in the packet structure are transmitted over the same transmitting communication path. 
     
     
       60. The apparatus according to  claim 59  wherein the first endpoint protocol signal comprises a signal indicating a protocol corresponding to data formatted in the frame structure, and wherein the second endpoint protocol signal comprises a signal indicating a protocol corresponding to data formatted in the packet structure. 
     
     
       61. The apparatus according to  claim 59  wherein the second endpoint protocol signal indicates an ethernet protocol, and wherein the data formatted in the packet structure is formatted according to the ethernet protocol. 
     
     
       62. The apparatus according to  claim 59  wherein the second endpoint protocol signal indicates a token-ring protocol, and wherein the data formatted in the packet structure is formatted according to the token-ring protocol. 
     
     
       63. The apparatus according to  claim 59  wherein the frame receiving circuitry includes packet converting circuitry for converting received data formatted in the frame structure into data formatted in the packet structure. 
     
     
       64. The apparatus according to  claim 63  wherein the second endpoint protocol signal indicates an ethernet protocol and wherein the data formatted in the packet structure is formatted according to the ethernet protocol. 
     
     
       65. The apparatus according to  claim 63  wherein the second endpoint protocol signal indicates a token-ring protocol, and wherein the data formatted in the packet structure is formatted according to the token-ring protocol. 
     
     
       66. The apparatus according to  claim 58  wherein the first sub circuit includes frame receiving circuitry for receiving data formatted in a frame structure, and the second sub-circuit includes isochronous receiving circuitry for receiving data formatted in an isochronous structure, wherein the received data formatted in the frame structure and the received data formatted in the isochronous structure are received over the same receiving communication path, and wherein the first sub-circuit further includes frame transmitting circuitry for transmitting data formatted in a frame structure, and the second sub-circuit further includes isochronous transmitting circuitry for transmitting data formatted in an isochronous structure, wherein the data formatted in the isochronous structure and the data formatted in the frame structure are transmitted over the same transmitting communication path. 
     
     
       67. The apparatus according to  claim 66  wherein the first endpoint protocol signal comprises a signal indicating a protocol corresponding to data formatted in the frame structure, and wherein the second endpoint protocol signal comprises a signal indicating a protocol corresponding to data formatted in the isochronous structure. 
     
     
       68. The apparatus according to  claim 66  wherein the second endpoint protocol signal indicates the isochronous protocol, and wherein the data formatted in the isochronous structure is communicated to the second endpoint according to the isochronous protocol. 
     
     
       69. The apparatus according to  claim 66  wherein the frame receiving circuitry includes isochronous converting circuitry for converting received data formatted in the frame structure into data formatted in the isochronous structure. 
     
     
       70. The apparatus according to  claim 69  wherein the second endpoint protocol signal indicates the isochronous protocol, and wherein the converted data formatted in the isochronous structure is communicated to the second endpoint according to the isochronous protocol. 
     
     
       71. The apparatus according to  claim 66  wherein the frame receiving circuitry includes packet converting circuitry for converting received data formatted in the frame structure into data formatted in the packet structure. 
     
     
       72. In a data communication network comprising at least first and second communication endpoints, an apparatus for establishing communication between the first and second endpoints comprising:
 a first endpoint transmitter coupled to the first endpoint for transmitting a first endpoint protocol signal to the second endpoint, the first endpoint protocol signal indicating a communication protocol, including a format for data transmission, with which the first endpoint is capable of communicating;  
 a second endpoint receiver coupled to the second endpoint for receiving the first endpoint protocol signal;  
 a second endpoint transmitter coupled to the second endpoint receiver for transmitting a second endpoint protocol signal, responsive to receipt of said said first endpoint protocol signal, to the first endpoint, the second endpoint protocol signal indicating a communication protocol, including a format for data transmission with which the second endpoint is capable of communicating;  
 a first endpoint receiver coupled to the first endpoint for receiving the second endpoint protocol signal;  
 a protocol identifying circuit coupled to the first endpoint receiver for identifying the communication protocol indicated by the second endpoint protocol signal from among a plurality of possible communication protocols with which the first endpoint is capable of communicating; and  
 a communication circuit in said first endpoint transmitter responsive to said protocol identifying circuit for communicating with the second endpoint using the communication protocol indicated by the second endpoint protocol signal.  
 
     
     
       73. In a data communication network comprising at least a first endpoint coupled to at least a second endpoint, an apparatus for establishing communication between the first endpoint and the second endpoint comprising:
   a first endpoint transmitter transmitting a first endpoint protocol signal to the second endpoint, the first endpoint protocol signal indicating a communication protocol, including a format for a data transmission, with which the first endpoint is capable of communicating;        a second endpoint receiver receiving the first endpoint protocol signal;        a second endpoint transmitter transmitting a second endpoint protocol signal to the first endpoint, the second endpoint protocol signal indicating a communication protocol, including a format for a data transmission, with which the second endpoint is capable of communicating;        wherein the communication protocol indicated by the second endpoint protocol signal is different from the communication protocol indicated by the first endpoint protocol signal;        a first endpoint receiver receiving the second endpoint protocol signal;        a first endpoint protocol identifying circuit coupled to the first endpoint receiver identifying the communication protocol indicated by the second endpoint protocol signal from among a plurality of possible communication protocols with which the first endpoint is capable of communicating; and        wherein the first endpoint transmitter includes a communication circuit for communicating with the second endpoint using the communication protocol indicated by the second endpoint protocol signal in response thereto.     
     
     
       74. The apparatus according to  claim 73 , wherein the first endpoint receiver includes frame receiving circuitry receiving data formatted in a frame structure, and packet receiving circuitry receiving data formatted in a packet structure and wherein the received data formatted in the frame structure and the received data formatted in the packet structure are received over the same receiving communication path, and wherein the first endpoint transmitter includes frame transmitting circuitry transmitting data formatted in the frame structure, and packet transmitting circuitry transmitting data formatted in the packet structure, wherein the data formatted in the frame structure and the data formatted in the packet structure are transmitted over the same transmitting communication path. 
     
     
       75. The apparatus according to  claim 74 , wherein the first endpoint protocol signal comprises a signal indicating a protocol corresponding to data formatted in the frame structure, and wherein the second endpoint protocol signal comprises a signal indicating a protocol corresponding to data formatted in the packet structure. 
     
     
       76. The apparatus according to  claim 74 , wherein the second endpoint protocol signal indicates an ethernet protocol, and wherein the data formatted in the packet structure is formatted according to the ethernet protocol. 
     
     
       77. The apparatus according to  claim 74 , wherein the second endpoint protocol signal indicates a token- ring protocol, and wherein the data formatted in the packet structure is formatted according to the token - ring protocol.   
     
     
       78. The apparatus according to  claim 74 , wherein the frame receiving circuitry includes packet converting circuitry converting received data formatted in the frame structure into data formatted in a packet structure. 
     
     
       79. The apparatus according to  claim 78 , wherein the second endpoint protocol signal indicates an ethernet protocol, and wherein the data formatted in the packet structure is formatted according to the ethernet protocol. 
     
     
       80. The apparatus according to  claim 78 , wherein the second endpoint protocol signal indicates a token- ring protocol, and wherein the data formatted in the packet structure is formatted according to the token - ring protocol.   
     
     
       81. The apparatus according to  claim 73 , wherein the first endpoint receiver includes frame receiving circuitry receiving data formatted in a frame structure, and isochronous receiving circuitry receiving data formatted in a isochronous structure, wherein the received data formatted in a frame structure and the received data formatted in the isochronous structure are received over the same receiving communication path, and wherein the first endpoint transmitter includes frame transmitting circuitry transmitting data formatted in a frame structure, and isochronous transmitting circuitry transmitting data formatted in an isochronous structure, wherein the data formatted in the isochronous structure and the data formatted in the frame structure are transmitted over the same transmitting communication path. 
     
     
       82. The apparatus according to  claim 81 , wherein the first endpoint protocol signal comprises a signal indicating a protocol corresponding to data formatted in the frame structure, and wherein the endpoint protocol signal comprises a signal indicating a protocol corresponding to data formatted in the isochronous structure. 
     
     
       83. The apparatus according to  claim 81 , wherein the second endpoint protocol signal indicates the isochronous protocol, and wherein the data formatted in the isochronous structure is communicated to the second endpoint according to the isochronous protocol. 
     
     
       84. The apparatus according to  claim 81 , wherein the frame receiving circuitry includes isochronous converting circuitry converting received data formatted in the frame structure into data formatted in the isochronous structure. 
     
     
       85. The apparatus according to  claim 84 , wherein the second endpoint protocol signal indicates the isochronous protocol, and wherein the converted data formatted in the isochronous structure is communicated to the second endpoint according to the isochronous protocol. 
     
     
       86. The apparatus according to  claim 81 , wherein the frame receiving circuitry includes packet converting circuitry converting received data formatted in the frame structure into data formatted in the packet structure. 
     
     
       87. An apparatus as set forth in  claim 73 , wherein the second endpoint transmitter transmits the second endpoint protocol signal responsive to the second endpoint receiver receiving the first endpoint protocol signal. 
     
     
       88. The apparatus of  claim 73 , wherein the first endpoint and the second endpoint are configured to operate in a best or desired manner. 
     
     
       89. The apparatus of  claim 73 , wherein the first endpoint and the second endpoint are coupled together over at least one physical medium. 
     
     
       90. The apparatus of  claim 89 , wherein the physical medium comprises one or more physical media selected from the group consisting of twisted pair media, coaxial cable media and fiber optic media. 
     
     
       91. The apparatus of  claim 73 , wherein the first endpoint and the second endpoint communicate in accordance with a first protocol at a first point in time, wherein the first endpoint and the second endpoint communicate in accordance with a second protocol at a second point in time. 
     
     
       92. The apparatus of  claim 73 , wherein the first endpoint and the second endpoint communicate in accordance with a communication protocol that is determined automatically. 
     
     
       93. The apparatus of  claim 73 , wherein data communicated between the first endpoint and the second endpoint include isochronous data. 
     
     
       94. The apparatus of  claim 93 , wherein the isochronous data comprises telephone data and/or video data. 
     
     
       95. In a data communication network comprising at least a first endpoint coupled to at least a second endpoint, an apparatus for establishing communication between the first endpoint and the second endpoint comprising:
   a first endpoint transmitter transmitting a first endpoint protocol signal to a second endpoint receiver, the first endpoint protocol signal indicating a communication protocol, including a format for a data transmission, with which the first endpoint is capable of communicating;        a second endpoint protocol identifying circuit identifying the communication protocol indicated by the first endpoint protocol signal from among a plurality of possible communication protocols with which the second endpoint is capable of communicating; and        a second endpoint transmitter transmitting a second endpoint protocol signal to the first endpoint indicating that communication between the first endpoint and the second endpoint will take place with the protocol indicated by the first endpoint protocol signal.     
     
     
       96. The apparatus according to  claim 95 , wherein the second endpoint receiver includes frame receiving circuitry receiving data formatted in a frame structure, and packet receiving circuitry receiving data formatted in a packet structure, wherein the received data formatted in the frame structure and the received data formatted in the packet structure are received over the same receiving communication path, and wherein the second endpoint transmitter includes frame transmitting circuitry transmitting data formatted in the frame structure, and packet transmitting circuitry transmitting data formatted in the packet structure, wherein the data formatted in the frame structure and the data formatted in the packet structure are transmitted over the same transmitting communication path. 
     
     
       97. The apparatus according to  claim 96 , wherein the first endpoint protocol signal indicates an ethernet protocol, and wherein the data formatted in the packet structure is formatted according to the ethernet protocol. 
     
     
       98. The apparatus according to  claim 96 , wherein the first endpoint protocol signal indicates a token- ring protocol, and wherein the data formatted in the packet structure is formatted according to the token - ring protocol.   
     
     
       99. The apparatus according to  claim 96 , wherein the frame receiving circuitry includes packet converting circuitry converting received data formatted in a frame structure into data formatted in a packet structure. 
     
     
       100. The apparatus according to  claim 95 , wherein the second endpoint receiver includes frame receiving circuitry receiving data formatted in a frame structure, and isochronous receiving circuitry receiving data formatted in an isochronous structure, wherein the received data formatted in the frame structure and the received data formatted in the isochronous structure are received over the same receiving communication path, and wherein the second endpoint transmitter includes frame transmitting circuitry transmitting data formatted in the frame structure, and isochronous transmitting circuitry transmitting data formatted in the isochronous structure, wherein the data formatted in the frame structure and the data formatted in the isochronous structure are transmitted over the same transmitting communication path. 
     
     
       101. The apparatus according to  claim 100 , wherein the first endpoint protocol signal indicates an isochronous protocol, and wherein the transmitted data formatted in the isochronous structure is communicated to the first endpoint according to the isochronous protocol. 
     
     
       102. The apparatus according to  claim 100 , wherein the frame receiving circuitry includes isochronous converting circuitry converting received data formatted in the frame structure into data formatted in the isochronous structure. 
     
     
       103. The apparatus of  claim 95 , wherein the first endpoint and the second endpoint are configured to operate in a best or desired manner. 
     
     
       104. The apparatus of  claim 95 , wherein the first endpoint and the second endpoint are coupled together over at least one physical medium. 
     
     
       105. The apparatus of  claim 104 , wherein the physical medium comprises one or more physical media selected from the group consisting of twisted pair media, coaxial cable media and fiber optic media. 
     
     
       106. The apparatus of  claim 95 , wherein the first endpoint and the second endpoint communicate in accordance with a first protocol at a first point in time, wherein the first endpoint and the second endpoint communicate in accordance with a second protocol at a second point in time. 
     
     
       107. The apparatus of  claim 95 , wherein the first endpoint and the second endpoint communicate in accordance with a communication protocol that is determined automatically. 
     
     
       108. The apparatus of  claim 95 , wherein data communicated between the first endpoint and the second endpoint include isochronous data. 
     
     
       109. The apparatus of  claim 108 , wherein the isochronous data comprises telephone data and/or video data. 
     
     
       110. In a data communication network comprising at least a first endpoint coupled to at least a second endpoint, an apparatus for establishing communication between the first endpoint and a second endpoint comprising:
   a first endpoint transmitter transmitting a first endpoint protocol signal to the second endpoint, the first endpoint protocol signal indicating one of a plurality of communication protocols, including a format for a data transmission, with which the first endpoint is capable of communicating;        a second endpoint receiver receiving the first endpoint protocol signal;        a second endpoint protocol identifying circuit identifying the communication protocol indicated by the first endpoint protocol signal from among a plurality of communication protocols with which the second endpoint is capable of communicating;        a second endpoint transmitter transmitting a second endpoint protocol signal to the first endpoint, the second endpoint protocol signal indicating the communication protocol indicated by the first endpoint protocol signal if the communication protocol indicated by the first endpoint protocol signal is a communication protocol, including a format for a data transmission, with which the second endpoint is capable of communicating;        a first endpoint receiver receiving the second endpoint protocol signal;        a first endpoint protocol identifying circuit identifying the communication protocol indicated by the second endpoint protocol signal from among a plurality of communication protocols with which the first endpoint is capable of communicating;        wherein the first endpoint transmitter includes a communication circuit communicating with the second endpoint using the communication protocol indicated by the second endpoint protocol signal.     
     
     
       111. The apparatus according to  claim 110 , wherein the data communication network comprises a plurality of second endpoints and the data communication network is configured in a star topology. 
     
     
       112. The apparatus according to  claim 110 , wherein the data communication network comprises a plurality of first endpoints wherein the first endpoints are configured in a ring topology. 
     
     
       113. The apparatus according to  claim 110 , wherein the data communication network comprises a plurality of second endpoints and wherein the second endpoints are configured in a tree topology. 
     
     
       114. The apparatus according to  claim 110 , wherein the first endpoint protocol signal comprises a series of  100  nanosecond pulses occurring at nominal  16  millisecond intervals. 
     
     
       115. The apparatus according to  claim 110 , wherein the first endpoint receiver includes frame receiving circuitry receiving data formatted in a frame structure, and packet receiving circuitry receiving data formatted in a packet structure, wherein the received data formatted in a frame structure and the received data formatted in the packet structure are received over the same receiving communication path, and wherein the first endpoint transmitter includes frame transmitting circuitry transmitting data formatted in a frame structure, and packet transmitting circuitry transmitting data formatted in a packet structure, wherein the transmitted data formatted in the frame structure and the transmitted data formatted in the packet structure are transmitted over the same transmitting communication path. 
     
     
       116. The apparatus according to  claim 115 , wherein the first endpoint protocol signal comprises a signal indicating a protocol corresponding to data formatted in the frame structure, and wherein the second endpoint protocol signal comprises a signal indicating a protocol corresponding to data formatted in the frame structure. 
     
     
       117. The apparatus according to  claim 115 , wherein the first endpoint protocol signal indicates an isochronous- ethernet protocol, and wherein the transmitted data formatted in the frame structure is formatted according to the isochronous - ethernet protocol.   
     
     
       118. The apparatus according to  claim 115 , wherein the first endpoint protocol signal indicates an isochronous- token ring protocol, and wherein the transmitted data formatted in the frame structure is formatted according to the isochronous - token ring protocol.   
     
     
       119. The apparatus according to  claim 115 , wherein the first endpoint protocol signal indicates an ethernet protocol, and wherein the transmitted data formatted in the packet structure is formatted according to the ethernet protocol. 
     
     
       120. The apparatus according to  claim 115 , wherein the first endpoint protocol signal indicates a token- ring protocol, and wherein the transmitted data formatted in the packet structure is formatted according to the token - ring protocol.   
     
     
       121. The apparatus according to  claim 115 , wherein the frame receiving circuitry includes packet converting circuitry converting received data formatted in the frame structure into data formatted in the packet structure. 
     
     
       122. The apparatus according to  claim 121 , wherein the first endpoint protocol signal indicates an ethernet protocol, and wherein the transmitted data formatted in the packet structure is formatted according to the ethernet protocol. 
     
     
       123. The apparatus according to  claim 121 , wherein the first endpoint protocol signal indicates a token- ring protocol, and wherein the transmitted data formatted in the packet structure is formatted according to the token - ring protocol.   
     
     
       124. The apparatus according to  claim 121 , wherein the first endpoint protocol signal indicates an isochronous- ethernet protocol, and wherein the transmitted data formatted in the frame structure is formatted according to the isochronous - ethernet protocol.   
     
     
       125. The apparatus according to  claim 121 , wherein the first endpoint protocol signal indicates an isochronous- token ring protocol, and wherein the transmitted data formatted in the frame structure is formatted according to the isochronous - token ring protocol.   
     
     
       126. The apparatus according to  claim 115 , wherein the frame receiving circuitry includes isochronous converting circuitry converting received data formatted in a frame structure into data formatted in an isochronous structure. 
     
     
       127. The apparatus according to  claim 126 , wherein the first endpoint protocol signal indicates an isochronous protocol. 
     
     
       128. An apparatus as set forth in  claim 110 , wherein the second endpoint transmitter transmits the second endpoint protocol signal responsive to the second endpoint receiver receiving the first endpoint protocol signal. 
     
     
       129. The apparatus according to  claim 110 , wherein the first endpoint receiver includes frame receiving circuitry receiving data formatted in a frame structure, and isochronous receiving circuitry receiving data formatted in an isochronous structure, wherein the received data formatted in a frame structure and the received data formatted in the isochronous structure are received over the same receiving communication path, and wherein the first endpoint transmitter includes frame transmitting circuitry transmitting data formatted in a frame structure, and isochronous transmitting circuitry transmitting data formatted in an isochronous structure, wherein the transmitted data formatted in the frame structure and the transmitted data formatted in the isochronous structure are transmitted over the same transmitting communication path. 
     
     
       130. The apparatus according to  claim 129 , wherein the first endpoint protocol signal indicates an isochronous protocol. 
     
     
       131. The apparatus according to  claim 129 , wherein the first endpoint protocol signal indicates an isochronous- ethernet protocol, and wherein the transmitted data formatted in the frame structure is formatted according to the isochronous - ethernet protocol.   
     
     
       132. The apparatus according to  claim 129 , wherein the first endpoint protocol signal indicates an isochronous- token ring protocol, and wherein the transmitted data formatted in the frame structure is formatted according to the isochronous - token ring protocol.   
     
     
       133. The apparatus according to  claim 129 , wherein the frame receiving circuitry includes isochronous converting circuitry converting received data formatted in a frame structure into data formatted in an isochronous structure. 
     
     
       134. The apparatus according to  claim 133 , wherein the first endpoint protocol signal indicates an isochronous protocol. 
     
     
       135. The apparatus according to  claim 134 , wherein the first endpoint protocol signal indicates an isochronous- ethernet protocol, and wherein the transmitted data formatted in the frame structure is formatted according to the isochronous - ethernet protocol.   
     
     
       136. The apparatus according to  claim 133 , wherein the first endpoint protocol signal indicates an isochronous- token ring protocol, and wherein the transmitted data formatted in the frame structure is formatted according to the isochronous - token ring protocol.   
     
     
       137. The apparatus according to  claim 133 , wherein the frame receiving circuitry includes packet converting circuitry converting received data formatted in a frame structure into data formatted in a packet structure. 
     
     
       138. The apparatus according to  claim 137 , wherein the first endpoint protocol signal indicates an ethernet protocol, and wherein the transmitted data formatted in the packet structure is formatted according to the ethernet protocol. 
     
     
       139. The apparatus according to  claim 137 , wherein the first endpoint protocol signal indicates a token- ring protocol, and wherein the transmitted data formatted in the packet structure is formatted according to the token - ring protocol.   
     
     
       140. The apparatus according to  claim 137 , wherein the first endpoint protocol signal indicates an isochronous- ethernet protocol, and wherein the transmitted data formatted in the frame structure formatted according to the isochronous - ethernet protocol.   
     
     
       141. The apparatus according to  claim 137 , wherein the first endpoint protocol signal indicates an isochronous- token ring protocol, and wherein the transmitted data formatted in the frame structure is formatted according to the isochronous - token ring protocol.   
     
     
       142. The apparatus according to  claim 137 , wherein the first endpoint protocol signal indicates an isochronous protocol. 
     
     
       143. The apparatus of  claim 110 , wherein the first endpoint and the second endpoint are configured to operate in a best or desired manner. 
     
     
       144. The apparatus of  claim 110 , wherein the first endpoint and the second endpoint are coupled together over at least one physical medium. 
     
     
       145. The apparatus of  claim 144 , wherein the physical medium comprises one or more physical media selected from the group consisting of twisted pair media, coaxial cable media and fiber optic media. 
     
     
       146. The apparatus of  claim 110 , wherein the first endpoint and the second endpoint communicate in accordance with a first protocol at a first point in time, wherein the first endpoint and the second endpoint communicate in accordance with a second protocol at a second point in time. 
     
     
       147. The apparatus of  claim 110 , wherein the first endpoint and the second endpoint communicate in accordance with a communication protocol that is determined automatically. 
     
     
       148. The apparatus of  claim 110 , wherein data communicated between the first endpoint and the second endpoint include isochronous data. 
     
     
       149. The apparatus of  claim 148 , wherein the isochronous data comprises telephone data and/or video data. 
     
     
       150. In a data communication network comprising at least first and second communication endpoints, an apparatus for establishing communication between the first and second endpoints comprising:
   a first endpoint transmitter transmitting a first endpoint protocol signal to the second endpoint, the first endpoint protocol signal indicating a communication protocol, including a format for a data transmission, with which the first endpoint is capable of communicating;        a second endpoint receiver receiving the first endpoint protocol signal;        a second endpoint transmitter transmitting a second endpoint protocol signal to the first endpoint, the second endpoint protocol signal indicating a communication protocol, including a format for a data transmission, with which the second endpoint is capable of communicating;        a first endpoint receiver receiving the second endpoint protocol signal;        a first endpoint protocol identifying circuit identifying the communication protocol indicated by the second endpoint protocol signal from among a plurality of possible communication protocols with which the first endpoint is capable of communicating; and        a first endpoint communication circuit responsive to the first endpoint protocol identifying circuit for communicating with the second endpoint using the communication protocol indicated by the second endpoint protocol signal.     
     
     
       151. The apparatus according to  claim 150 , wherein the first endpoint communication circuit includes a first receiver sub- circuit in the first endpoint receiver and a first transmitter sub - circuit in the first endpoint transmitter for communicating using a first communication protocol and a second receiver sub - circuit in the first endpoint receiver and a second transmitter sub - circuit in the first endpoint transmitter for communicating using a second communication protocol, and wherein the communication circuit communicates with the second endpoint using one of the first receiver and transmitter sub - circuits and the second receiver and transmitter sub - circuits responsive to the second endpoint protocol signal.   
     
     
       152. The apparatus according to  claim 151 , wherein the first sub- circuit includes frame receiving circuitry receiving data formatted in a frame structure, and the second sub - circuit includes packet receiving circuitry receiving data formatted in a packet structure and wherein the received data formatted in the frame structure and the received data formatted in the packet structure are received over the same receiving communication path, and wherein the first sub - circuit further includes frame transmitting circuitry transmitting data formatted in the frame structure, and the second sub - circuit includes packet transmitting circuitry transmitting data formatted in the packet structure, wherein the data formatted in the frame structure and the data formatted in the packet structure are transmitted over the same transmitting communication path.   
     
     
       153. The apparatus according to  claim 152 , wherein the first endpoint protocol signal comprises a signal indicating a protocol corresponding to data formatted in the frame structure, and wherein the second endpoint protocol signal comprises a signal indicating a protocol corresponding to data formatted in the packet structure. 
     
     
       154. The apparatus according to  claim 152 , wherein the second endpoint protocol signal indicates an ethernet protocol, and wherein the data formatted in the packet structure is formatted according to the ethernet protocol. 
     
     
       155. The apparatus according to  claim 152 , wherein the second endpoint protocol signal indicates a token- ring protocol, and wherein the data formatted in the packet structure is formatted according to the token - ring protocol.   
     
     
       156. The apparatus according to  claim 152 , wherein the frame receiving circuitry includes packet converting circuitry converting received data formatted in the frame structure into data formatted in the packet structure. 
     
     
       157. The apparatus according to  claim 156 , wherein the second endpoint protocol signal indicates an ethernet protocol, and wherein the data formatted in the packet structure is formatted according to the ethernet protocol. 
     
     
       158. The apparatus according to  claim 156 , wherein the second endpoint protocol signal indicates a token- ring protocol, and wherein the data formatted in the packet structure is formatted according to the token - ring protocol.   
     
     
       159. The apparatus according to  claim 151 , wherein the first sub- circuit includes frame receiving circuitry receiving data formatted in a frame structure, and the second sub - circuit includes isochronous receiving circuitry receiving data formatted in an isochronous structure, wherein the received data formatted in the frame structure and the received data formatted in the isochronous structure are received over the same receiving communication path, and wherein the first sub - circuit further includes frame transmitting circuitry transmitting data formatted in a frame structure, and the second sub - circuit further includes isochronous transmitting circuitry transmitting data formatted in an isochronous structure, wherein the data formatted in the isochronous structure and the data formatted in the frame structure are transmitted over the same transmitting communication path.   
     
     
       160. The apparatus according to  claim 159 , wherein the first endpoint protocol signal comprises a signal indicating a protocol corresponding to data formatted in the frame structure, and wherein the second endpoint protocol signal comprises a signal indicating a protocol corresponding to data formatted in the isochronous structure. 
     
     
       161. The apparatus according to  claim 159 , wherein the second endpoint protocol signal indicates the isochronous protocol, and wherein the data formatted in the isochronous structure is communicated to the second endpoint according to the isochronous protocol. 
     
     
       162. The apparatus according to  claim 159 , wherein the frame receiving circuitry includes isochronous converting circuitry for converting received data formatted in the frame structure into data formatted in the isochronous structure. 
     
     
       163. The apparatus according to  claim 162 , wherein the second endpoint protocol signal indicates the isochronous protocol, and wherein the converted data formatted in the isochronous structure is communicated to the second endpoint according to the isochronous protocol. 
     
     
       164. The apparatus according to  claim 159 , wherein the frame receiving circuitry includes packet converting circuitry converting received data formatted in the frame structure into data formatted in the packet structure. 
     
     
       165. The apparatus of  claim 150 , wherein the first endpoint and the second endpoint are configured to operate in a best or desired manner. 
     
     
       166. The apparatus of  claim 150 , wherein the first endpoint and the second endpoint are coupled together over at least one physical medium. 
     
     
       167. The apparatus of  claim 166 , wherein the physical medium comprises one or more physical media selected from the group consisting of twisted pair media, coaxial cable media and fiber optic media. 
     
     
       168. The apparatus of  claim 150 , wherein the first endpoint and the second endpoint communicate in accordance with a first protocol at a first point in time, wherein the first endpoint and the second endpoint communicate in accordance with a second protocol at a second point in time. 
     
     
       169. The apparatus of  claim 150 , wherein the first endpoint and the second endpoint communicate in accordance with a communication protocol that is determined automatically. 
     
     
       170. The apparatus of  claim 150 , wherein data communicated between the first endpoint and the second endpoint include isochronous data. 
     
     
       171. The apparatus of  claim 170 , wherein the isochronous data comprises telephone data and/or video data. 
     
     
       172. In a data communication network comprising at least first and second communication endpoints, an apparatus for establishing communication between the first and second endpoints comprising:
   a first endpoint transmitter transmitting a first endpoint protocol signal to the second endpoint, the first endpoint protocol signal indicating a communication protocol, including a format for a data transmission, with which the first endpoint is capable of communicating;        a second endpoint receiver receiving the first endpoint protocol signal;        a second endpoint transmitter transmitting a second endpoint protocol signal, responsive to receipt of the first endpoint protocol signal, to the first endpoint, the second endpoint protocol signal indicating a communication protocol, including a format for a data transmission, with which the second endpoint is capable of communicating;        a first endpoint receiver receiving the second endpoint protocol signal;        a first endpoint protocol identifying circuit identifying the communication protocol indicated by the second endpoint protocol signal from among a plurality of possible communication protocols with which the first endpoint is capable of communicating; and        a first endpoint communication circuit communicating with the second endpoint using the communication protocol indicated by the second endpoint protocol signal.     
     
     
       173. The apparatus of  claim 172 , wherein the first endpoint and the second endpoint are configured to operate in a best or desired manner. 
     
     
       174. The apparatus of  claim 172 , wherein the first endpoint and the second endpoint are coupled together over at least one physical medium. 
     
     
       175. The apparatus of  claim 174 , wherein the physical medium comprises one or more physical media selected from the group consisting of twisted pair media, coaxial cable media and fiber optic media. 
     
     
       176. The apparatus of  claim 172 , wherein the first endpoint and the second endpoint communicate in accordance with a first protocol at a first point in time, wherein the first endpoint and the second endpoint communicate in accordance with a second protocol at a second point in time. 
     
     
       177. The apparatus of  claim 172 , wherein the first endpoint and the second endpoint communicate in accordance with a communication protocol that is determined automatically. 
     
     
       178. The apparatus of  claim 172 , wherein data communicated between the first endpoint and the second endpoint include isochronous data. 
     
     
       179. The apparatus of  claim 178 , wherein the isochronous data comprises telephone data and/or video data. 
     
     
       180. In a data communication network comprising at least one first endpoint coupled to at least one second endpoint, a method in a system for establishing communication between a first endpoint and a second endpoint comprising the steps of:
   transmitting a first endpoint protocol signal from a first endpoint transmitter to the second endpoint, the first endpoint protocol signal indicating a communication protocol, including a format for a data transmission, with which the first endpoint is capable of communicating;        receiving the first endpoint protocol signal with a second endpoint receiver;        transmitting a second endpoint protocol signal from a second endpoint transmitter to the first endpoint, the second endpoint protocol signal indicating a communication protocol, including a format for a data transmission, with which the second endpoint is capable of communicating;        wherein the communication protocol indicated by the second endpoint protocol signal is different from the communication protocol indicated by the first endpoint protocol signal;        receiving the second endpoint protocol signal with a first endpoint receiver;        identifying the communication protocol indicated by the second endpoint protocol signal from among a plurality of possible communication protocols with which the first endpoint is capable of communicating; and        wherein the first endpoint transmitter communicates with the second endpoint using the communication protocol indicated by the second endpoint protocol signal.     
     
     
       181. The method of  claim 180 , wherein the first endpoint and the second endpoint are configured to operate in a best or desired manner. 
     
     
       182. The method of  claim 180 , wherein the first endpoint and the second endpoint are coupled together over at least one physical medium. 
     
     
       183. The method of  claim 182 , wherein the physical medium comprises one or more physical media selected from the group consisting of twisted pair media, coaxial cable media and fiber optic media. 
     
     
       184. The method of  claim 180 , wherein the first endpoint and the second endpoint communicate in accordance with a first protocol at a first point in time, wherein the first endpoint and the second endpoint communicate in accordance with a second protocol at a second point in time. 
     
     
       185. The method of  claim 180 , wherein the first endpoint and the second endpoint communicate in accordance with a communication protocol that is determined automatically. 
     
     
       186. The method of  claim 180 , wherein data communicated between the first endpoint and the second endpoint include isochronous data. 
     
     
       187. The method of  claim 186 , wherein the isochronous data comprises telephone data and/or video data. 
     
     
       188. The method of  claim 180 , wherein the first endpoint is coupled to a plurality of second endpoints through a plurality of physical media. 
     
     
       189. The method of  claim 188 , wherein the physical media comprises one or more physical media selected from the group consisting of twisted pair media, coaxial cable media and fiber optic media. 
     
     
       190. The method of  claim 180 , further comprising the step of establishing a direct connection between the first endpoint and the second endpoint. 
     
     
       191. The method of  claim 180 , wherein the first endpoint and the second endpoint communicate in accordance with one of a plurality of LAN protocols. 
     
     
       192. In a data communication network comprising at least one first endpoint coupled to at least one second endpoint, a method in a system for establishing communication between a first endpoint and a second endpoint comprising the steps of:
   transmitting a first endpoint protocol signal from a first endpoint transmitter to the second endpoint, the first endpoint protocol signal indicating a communication protocol, including a format for a data transmission, with which the first endpoint is capable of communicating;        identifying the communication protocol indicated by the first endpoint protocol signal from among a plurality of possible communication protocols, including a format for a data transmission, with which the second endpoint is capable of communicating; and        transmitting a second endpoint protocol signal to the first endpoint indicating that communication between the first endpoint and the second endpoint will take place with the protocol indicated by the first endpoint protocol signal.     
     
     
       193. The method of  claim 192 , wherein the first endpoint and the second endpoint are configured to operate in a best or desired manner. 
     
     
       194. The method of  claim 192 , wherein the first endpoint and the second endpoint are coupled together over at least one physical medium. 
     
     
       195. The method of  claim 194 , wherein the physical medium comprises one or more physical media selected from the group consisting of twisted pair media, coaxial cable media and fiber optic media. 
     
     
       196. The method of  claim 192 , wherein the first endpoint and the second endpoint communicate in accordance with a first protocol at a first point in time, wherein the first endpoint and the second endpoint communicate in accordance with a second protocol at a second point in time. 
     
     
       197. The method of  claim 192 , wherein the first endpoint and the second endpoint communicate in accordance with a communication protocol that is determined automatically. 
     
     
       198. The method of  claim 192 , wherein data communicated between the first endpoint and the second endpoint include isochronous data. 
     
     
       199. The method of  claim 198 , wherein the isochronous data comprises telephone data and/or video data. 
     
     
       200. The method of  claim 192 , wherein the first endpoint is coupled to a plurality of second endpoints through a plurality of physical media. 
     
     
       201. The method of  claim 200 , wherein the physical media comprises one or more physical media selected from the group consisting of twisted pair media, coaxial cable media and fiber optic media. 
     
     
       202. The method of  claim 192 , further comprising the step of establishing a direct connection between the first endpoint and the second endpoint. 
     
     
       203. The method of  claim 192 , wherein the first endpoint and the second endpoint communicate in accordance with one of a plurality of LAN protocols. 
     
     
       204. In a data communication network comprising at least one first endpoint coupled to at least one second endpoint, a method in a system for establishing communication between a first endpoint and a second endpoint comprising the steps of:
   transmitting a first endpoint protocol signal from a first endpoint to the second endpoint, the first endpoint protocol signal indicating one of a plurality of communication protocols, including a format for a data transmission, with which the first endpoint is capable of communicating;        receiving the first endpoint protocol signal with a second endpoint receiver;        identifying the communication protocol indicated by the first endpoint protocol signal from among a plurality of communication protocols with which the second endpoint is capable of communicating;        transmitting a second endpoint protocol signal to the first endpoint, the second endpoint protocol signal indicating the communication protocol indicated by the first endpoint protocol signal if the communication protocol indicated by the first endpoint protocol signal is a communication protocol, including a format for a data transmission, with which the second endpoint is capable of communicating;        receiving the second endpoint protocol signal with the first endpoint;        identifying the communication protocol indicated by the second endpoint protocol signal from among a plurality of communication protocols with which the first endpoint is capable of communicating; and        wherein the first endpoint transmitter communicates with the second endpoint using the communication protocol indicated by the second endpoint protocol signal.     
     
     
       205. The method of  claim 204 , wherein the first endpoint and the second endpoint are configured to operate in a best or desired manner. 
     
     
       206. The method of  claim 204 , wherein the first endpoint and the second endpoint are coupled together over at least one physical medium. 
     
     
       207. The method of  claim 206 , wherein the physical medium comprises one or more physical media selected from the group consisting of twisted pair media, coaxial cable media and fiber optic media. 
     
     
       208. The method of  claim 204 , wherein the first endpoint and the second endpoint communicate in accordance with a first protocol at a first point in time, wherein the first endpoint and the second endpoint communicate in accordance with a second protocol at a second point in time. 
     
     
       209. The method of  claim 204 , wherein the first endpoint and the second endpoint communicate in accordance with a communication protocol that is determined automatically. 
     
     
       210. The method of  claim 204 , wherein data communicated between the first endpoint and the second endpoint include isochronous data. 
     
     
       211. The method of  claim 210 , wherein the isochronous data comprises telephone data and/or video data. 
     
     
       212. The method of  claim 204 , wherein the first endpoint is coupled to a plurality of second endpoints through a plurality of physical media. 
     
     
       213. The method of  claim 212 , wherein the physical media comprises one or more physical media selected from the group consisting of twisted pair media, coaxial cable media and fiber optic media. 
     
     
       214. The method of  claim 204 , further comprising the step of establishing a direct connection between the first endpoint and the second endpoint. 
     
     
       215. The method of  claim 204 , wherein the first endpoint and the second endpoint communicate in accordance with one of a plurality of LAN protocols. 
     
     
       216. In a data communication network comprising at least first and second endpoints, a method in a system for establishing communication between the first and second endpoints comprising the steps of:
   transmitting a first endpoint protocol signal from a first endpoint to the second endpoint, the first endpoint protocol signal indicating a communication protocol, including a format for a data transmission, with which the first endpoint is capable of communicating;        receiving the first endpoint protocol signal at the second endpoint;        transmitting a second endpoint protocol signal from the second endpoint to the first endpoint, the second endpoint protocol signal indicating a communication protocol, including a format for a data transmission, with which the second endpoint is capable of communicating;        receiving the second endpoint protocol signal at the first endpoint;        identifying the communication protocol indicated by the second endpoint protocol signal from among a plurality of possible communication protocols with which the first endpoint is capable of communicating; and        communicating between the first endpoint and the second endpoint using the communication protocol indicated by the second endpoint protocol signal.     
     
     
       217. The method of  claim 216 , wherein the first endpoint and the second endpoint are configured to operate in a best or desired manner. 
     
     
       218. The method of  claim 216 , wherein the first endpoint and the second endpoint are coupled together over at least one physical medium. 
     
     
       219. The method of  claim 218 , wherein the physical medium comprises one or more physical media selected from the group consisting of twisted pair media, coaxial cable media and fiber optic media. 
     
     
       220. The method of  claim 216 , wherein the first endpoint and the second endpoint communicate in accordance with a first protocol at a first point in time, wherein the first endpoint and the second endpoint communicate in accordance with a second protocol at a second point in time. 
     
     
       221. The method of  claim 216 , wherein the first endpoint and the second endpoint communicate in accordance with a communication protocol that is determined automatically. 
     
     
       222. The method of  claim 216 , wherein data communicated between the first endpoint and the second endpoint include isochronous data. 
     
     
       223. The method of  claim 222 , wherein the isochronous data comprises telephone data and/or video data. 
     
     
       224. The method of  claim 216 , wherein the first endpoint is coupled to a plurality of second endpoints through a plurality of physical media. 
     
     
       225. The method of  claim 224 , wherein the physical media comprises one or more physical media selected from the group consisting of twisted pair media, coaxial cable media and fiber optic media. 
     
     
       226. The method of  claim 216 , further comprising the step of establishing a direct connection between the first endpoint and the second endpoint. 
     
     
       227. The method of  claim 216 , wherein the first endpoint and the second endpoint communicate in accordance with one of a plurality of LAN protocols. 
     
     
       228. In a data communication network comprising at least first and second endpoints, a method in a system for establishing communication between the first and second endpoints comprising the steps of:
   transmitting a first endpoint protocol signal from a first endpoint to the second endpoint, the first endpoint protocol signal indicating a communication protocol, including a format for a data transmission, with which the first endpoint is capable of communicating;        receiving the first endpoint protocol signal at the second endpoint;        transmitting a second endpoint protocol signal, responsive to receipt of the first endpoint protocol signal, from the second endpoint to the first endpoint, the second endpoint protocol signal indicating a communication protocol, including a format for a data transmission, with which the second endpoint is capable of communicating;        receiving the second endpoint protocol signal at the first endpoint;        identifying the communication protocol indicated by the second endpoint protocol signal from among a plurality of possible communication protocols with which the first endpoint is capable of communicating; and        communicating between the first endpoint and the second endpoint using the communication protocol indicated by the second endpoint protocol signal.     
     
     
       229. The method of  claim 228 , wherein the first endpoint and the second endpoint are configured to operate in a best or desired manner. 
     
     
       230. The method of  claim 228 , wherein the first endpoint and the second endpoint are coupled together over at least one physical medium. 
     
     
       231. The method of  claim 230 , wherein the physical medium comprises one or more physical media selected from the group consisting of twisted pair media, coaxial cable media and fiber optic media. 
     
     
       232. The method of  claim 228 , wherein the first endpoint and the second endpoint communicate in accordance with a first protocol at a first point in time, wherein the first endpoint and the second endpoint communicate in accordance with a second protocol at a second point in time. 
     
     
       233. The method of  claim 228 , wherein the first endpoint and the second endpoint communicate in accordance with a communication protocol that is determined automatically. 
     
     
       234. The method of  claim 228 , wherein data communicated between the first endpoint and the second endpoint include isochronous data. 
     
     
       235. The method of  claim 234 , wherein the isochronous data comprises telephone data and/or video data. 
     
     
       236. The method of  claim 228 , wherein the first endpoint is coupled to a plurality of second endpoints through a plurality of physical media. 
     
     
       237. The method of  claim 236 , wherein the physical media comprises one or more physical media selected from the group consisting of twisted pair media, coaxial cable media and fiber optic media. 
     
     
       238. The method of  claim 228 , further comprising the step of establishing a direct connection between the first endpoint and the second endpoint. 
     
     
       239. The method of  claim 228 , wherein the first endpoint and the second endpoint communicate in accordance with one of a plurality of LAN protocols. 
     
     
       240. In a data communication network comprising at least one first endpoint coupled to at least one second endpoint, a method in a system for establishing communication between a first endpoint and a second endpoint comprising the steps of:
   transmitting a first endpoint protocol signal from a first endpoint transmitter to the second endpoint, the first endpoint protocol signal indicating a communication protocol, including a format for a data transmission, with which the first endpoint is capable of communicating;        identifying the communication protocol indicated by the first endpoint protocol signal from among a plurality of possible communication protocols with which the second endpoint is capable of communicating;        transmitting a second endpoint protocol signal to the first endpoint indicating that communication between the first endpoint and the second endpoint will take place with the protocol indicated by the first endpoint protocol signal;        the method further comprising the steps of:      transmitting the first endpoint protocol signal from the first endpoint to the second endpoint;        receiving the first endpoint protocol signal with a second endpoint receiver;        identifying the communication protocol indicated by the first endpoint protocol signal from among the plurality of communication protocols with which the second endpoint is capable of communicating;        transmitting the second endpoint protocol signal to the first endpoint, the second endpoint protocol signal indicating the communication protocol indicated by the first endpoint protocol signal if the communication protocol indicated by the first endpoint protocol signal is a communication protocol, including a format for a data transmission, with which the second endpoint is capable of communicating;        receiving the second endpoint protocol signal with the first endpoint;        identifying the communication protocol indicated by the second endpoint protocol signal from among a plurality of communication protocols with which the first endpoint is capable of communicating;        wherein the first endpoint transmitter communicates with the second endpoint using the communication protocol indicated by the second endpoint protocol signal;        the method further comprising the steps of:      transmitting the first endpoint protocol signal from the first endpoint to the second endpoint;        receiving the first endpoint protocol signal at the second endpoint;        transmitting the second endpoint protocol signal from the second endpoint to the first endpoint;        receiving the second endpoint protocol signal at the first endpoint;        identifying the communication protocol indicated by the second endpoint protocol signal from among a plurality of possible communication protocols with which the first endpoint is capable of communicating; and        communicating between the first endpoint and the second endpoint using the communication protocol indicated by the second endpoint protocol signal.