ATM telecommunications systems and method for routing narrow band traffic

Abstract

A telecommunications system comprises an asynchronous transfer mode (ATM) network having uncommitted bandwidth, and a plurality of adaptive grooming routers (AGR) coupled to the network. The AGRs comprise a group adapted to function as a virtual transit exchange whose fabric and control are distributed over the group. The virtual comprising the AGRs incorporates independent connection control and call routing functions and has means for determining the current system status whereby to set up narrow band connections across the ATM network based on that status determination.

1. A telecommunications system comprising:
 an asynchronous transfer mode (ATM) network; and  
 a plurality of adaptive grooming routers (AGRs) coupled to the network, each AGR comprising an ATM switch including at least one adaptive virtual junctor (AVJ) for adapting narrowband traffic received at said AGR to/from the ATM adaptation layer,  
 wherein the AGRs are interconnected across the ATM network by virtual trunks and are arranged to function as a distributed narrowband exchange to set up narrowband connections across the ATM network.  
 
     
     
       2. A telecommunications system as claimed in  claim 1 , wherein a plurality of local exchanges are coupled to the network and wherein the local exchanges are dual homed to the network. 
     
     
       3. A telecommunications system as claimed in  claim 2 , wherein the network incorporates means for load balancing of traffic originating from the local exchanges. 
     
     
       4. A telecommunications system as claimed in  claim 1 , wherein the virtual transit exchange comprising the AGRs incorporates independent connection control and call routing functions. 
     
     
       5. A telecommunications system as claimed in  claim 4 , wherein the call routing function is adapted to perform a selection of potential voice routes and to prioritise that selection. 
     
     
       6. A telecommunications system as claimed in  claim 5 , wherein said prioritisation is performed from an assessment of congestion of said potential voice routes. 
     
     
       7. A telecommunications system as claimed in  claim 4 , wherein the service and connection aspects of the connection control function are separated whereby to facilitate support of advanced services and a plurality of connection models. 
     
     
       8. A telecommunications system as claimed in  claim 5 , wherein said call routing function incorporates means for determining availability of a destination and for rejecting at source traffic to that destination in the event that the destination is unavailable. 
     
     
       9. A telecommunications system as claimed in  claim 1  and incorporating means for providing a narrow band multicast function. 
     
     
       10. A telecommunications system as claimed in  claim 1  and incorporating means for voice path tracing whereby to effect failure recovery. 
     
     
       11. A telecommunications system as claimed in  claim 1  including means for determining the current traffic status of the system whereby to effect routing of narrow band traffic across the system. 
     
     
       12. A method of routing  handling telecommunications traffic in a telecommunications system, the method comprising the steps of:
 an asynchronous transfer mode (ATM) network; and 
 interconnecting a plurality of adaptive grooming  routers (AGRs)  coupled to thean asynchronous transfer mode ( ATM ) network, each AGR comprising an ATM switch including at least one adaptive virtual junctor (AVJ) for adapting narrowband traffic received at said AGR to/from the ATM adaptation layer,the interconnecting being by virtual trunks across the ATM network,  
 wherein the AGRs are interconnected across the ATM network by virtual trunks and are arrangedarranging the routers to function as a distributed narrowband exchange to set up narrowband connections across the ATM network; and  
 adapting narrowband traffic received at a said router to/from an ATM adaptation layer.  
 
     
     
       13. A method as claimed in  claim 12 , wherein  comprising determining a set of potential voice routes are determined  for a connection and wherein a prioritisation of  prioritizing said routes is performed  from an assessment of congestion of said potential voice routes. 
     
     
       14. A method as claimed in  claim 13 , wherein  comprising determining the availability of a destination is determined  and rejecting traffic to that destination at source in the event that the destination is unavailable. 
     
     
       15. A method as claimed in  claim 12 , wherein  comprising determining the current traffic status of the system is determined  prior to effecting routing of narrowband traffic across the system. 
     
     
       16. A telecommunications system comprising:
 an asynchronous transfer mode (ATM) network; and  
 a plurality of adaptive grooming routers (AGRs) coupled to the network, each AGR comprising an ATM switch including means for adapting narrowband traffic received at said AGR to/from the ATM adaptation layer,  
 wherein the AGRs are interconnected across the ATM network by virtual trunks and are arranged to function as a distributed narrowband exchange to set up narrowband connections across the ATM network.  
 
     
     
       17. A telecommunications system comprising:
   a broadband digital communications network; and        a plurality of adaptive grooming routers  ( AGRs )  coupled to the network, each AGR comprising a traffic switch including at least one adaptive virtual junctor  ( AVJ )  for adapting narrowband traffic received at said AGR to/from the network,        wherein the AGRs are interconnected across the network by virtual trunks and are arranged to function as a distributed narrowband exchange to set up narrowband connections across the network.     
     
     
       18. A telecommunications system according to  claim 17 , wherein a plurality of local exchanges are coupled to the network. 
     
     
       19. A telecommunications system according to  claim 18 , wherein the local exchanges are dual homed to the network. 
     
     
       20. A telecommunications system according to  claim 19 , wherein the network incorporates means for load balancing of traffic originating from the local exchanges. 
     
     
       21. A telecommunications system according to  claim 17 , wherein the distributed narrowband exchange incorporates independent connection control and call routing functions. 
     
     
       22. A telecommunications system according to  claim 21 , wherein the call routing function is arranged to perform a selection of at least one potential voice route. 
     
     
       23. A telecommunications system according to  claim 21 , wherein the call routing function is arranged to perform a selection of potential voice routes and to prioritise that selection. 
     
     
       24. A telecommunications system according to  claim 23 , wherein said prioritisation is performed from an assessment of congestion of said potential voice routes. 
     
     
       25. A telecommunications system according to  claim 21 , wherein connection control and call routing functions are separated whereby to facilitate support of advanced services and a plurality of connection models. 
     
     
       26. A telecommunications system according to  claim 21 , wherein said call routing function incorporates means for determining availability of a destination and for rejecting at source traffic to that destination in the event that the destination is unavailable. 
     
     
       27. A telecommunications system according to  claim 17  and incorporating means for providing a narrow band multicast function. 
     
     
       28. A telecommunications system according to  claim 17  and incorporating means for voice path tracing whereby to effect failure recovery. 
     
     
       29. A telecommunications system according to  claim 17  including means for determining the current traffic status of the system whereby to effect routing of narrow band traffic across the system. 
     
     
       30. A telecommunications system according to  claim 17 , wherein the network is a packet- switched network.   
     
     
       31. A telecommunications system according to  claim 17 , wherein the network is a connection- oriented network.   
     
     
       32. A telecommunications system according to  claim 31 , wherein the network is an asynchronous transfer mode ( ATM )  network.   
     
     
       33. A telecommunications system according to  claim 32 , wherein the traffic switch is an ATM traffic switch and the AVJ is for adapting narrowband traffic received at a said AGR to/from an ATM adaptation layer for the ATM network. 
     
     
       34. A telecommunications system according to  claim 17 , wherein the network is a wide area network ( WAN ). 
     
     
       35. A method of handling telecommunications traffic in a telecommunications system, the method comprising the steps of:
   interconnecting a plurality of routers coupled to a broadband digital communications network, the interconnecting being by virtual trunks across the network;        arranging the routers to function as a distributed narrowband exchange to set up narrowband connections across the network; and        adapting narrowband traffic received at a said router to/from the network.     
     
     
       36. A method according to  claim 35 , comprising determining one or more potential voice routes for a connection. 
     
     
       37. A method as claimed in  35 , comprising determining a set of potential voice routes for a connection and prioritizing said routes from an assessment of congestion of said potential voice routes. 
     
     
       38. A method as claimed in  35 , comprising determining the availability of a destination and rejecting traffic to that destination at source in the event that the destination is unavailable. 
     
     
       39. A method as claimed in  35 , comprising determining the current traffic status of the system prior to effecting routing of narrowband traffic across the system. 
     
     
       40. A method according to  claim 35 , wherein the network is a packet- switched network.   
     
     
       41. A method according to  claim 35 , wherein the network is a connection- oriented network.   
     
     
       42. A method according to  claim 41 , wherein the network is an asynchronous transfer mode ( ATM )  network.   
     
     
       43. A method according to  claim 35 , wherein the network is a wide area network ( WAN ). 
     
     
       44. An adaptive grooming router ( AGR )  for use in a telecommunications system comprising a broadband digital communications network to which the AGR may be coupled, the AGR comprising:      a traffic switch including at least one adaptive virtual junctor  ( AVJ )  for adapting narrowband traffic received at said AGR to/from the network, and        an interface for interconnecting the AGR with one or more other AGRs across the network by virtual trunks,        wherein the AGR is arranged to function as at least part of a distributed narrowband exchange for setting up narrowband connections across the network.     
     
     
       45. An AGR according to  claim 44 , wherein the AGR incorporates a connection control function. 
     
     
       46. An AGR according to  claim 45 , wherein the AGR incorporates a call routing function. 
     
     
       47. An AGR according to  claim 46 , wherein the connection control function and the call routing functions are independent. 
     
     
       48. An AGR according to  claim 46 , wherein the call routing function is arranged to perform a selection of at least one potential voice routes. 
     
     
       49. An AGR according to  claim 46 , wherein the call routing function is arranged to perform a selection of potential voice routes and to prioritise that selection. 
     
     
       50. An AGR according to  claim 49 , wherein said prioritisation is performed from an assessment of congestion of said potential voice routes. 
     
     
       51. An AGR according to  claim 46 , wherein the connection control and call routing functions are separated whereby to facilitate support of advanced services and a plurality of connection models. 
     
     
       52. An AGR according to  claim 46 , wherein said call routing function incorporates means for determining availability of a destination and for rejecting at source traffic to that destination in the event that the destination is unavailable. 
     
     
       53. An AGR according to  claim 44 , wherein the network is a packet- switched network.   
     
     
       54. An AGR according to  claim 44 , wherein the network is a connection- oriented network.   
     
     
       55. An AGR according to  claim 54 , wherein the network is an asynchronous transfer mode ( ATM )  network.   
     
     
       56. An AGR according to  claim 55 , wherein the traffic switch is an ATM traffic switch and the AVJ is for adapting narrowband traffic received at said AGR to/from an ATM adaptation layer for the ATM network. 
     
     
       57. An AGR according to  claim 44 , wherein the network is a wide area network ( WAN ). 
     
     
       58. A method of routing traffic in a telecommunications system the method comprising the steps of:
   interconnecting a plurality of routers across a broadband digital communications network by virtual trunks;        setting up narrowband connections across the network using the virtual trunks, the plurality of routers thereby being arranged to function as a distributed narrowband exchange; and        adapting narrowband traffic received at one of said routers to/from the network.     
     
     
       59. A method according to  claim 58 , comprising the step of:
   determining one or more potential voice routes for a connection.     
     
     
       60. A method according to  claim 58 , comprising the steps of:
   determining a set of potential voice routes for a connection; and        prioritising said routes from an assessment of congestion of said potential voice routes.     
     
     
       61. A method according to  claim 58 , comprising the steps of:
   determining the availability of a destination; and        rejecting at source traffic to that destination in the event that the destination is unavailable.     
     
     
       62. A method according to  claim 58 , comprising the steps of:
   determining the current traffic status of the system; and        routing narrowband traffic across the system in dependence on the determined current traffic status.     
     
     
       63. A method according to  claim 58 , wherein the network is a packet- switched network.   
     
     
       64. A method according to  claim 58 , wherein the network is a connection- oriented network.   
     
     
       65. A method according to  claim 64 , wherein the network is an asynchronous transfer mode ( ATM )  network.   
     
     
       66. A method according to  claim 58 , wherein the network is a wide area network ( WAN ).