Universal SFP support

Abstract

Techniques for supporting optical and electrical protocols, such as on the ports of a line card in a network device, are provided. A port on a line card supports optical and electrical connections. The PHY monitors a signal to determine if the transmission connection at the port has changed, such as from optical to electrical, or vice versa. If there has been a change, the PHY is directed to reset a port to correspond to the appropriate transmission connection. By resetting the port, the PHY changes the protocol that is utilized with the signals (e.g., NRZI or 3-Level MLT3).

The invention claimed is: 
     
       1. A method of selecting optical or electrical transmissions on a port of a line card in a network device, the line card including an integrated circuit that supports optical and electrical transmissions, comprising:
 at powerup of the line card of the network device, configuring the port for a first transceiver module of a first transmission connection type connected to the line card; 
 after powerup of the line card of the network device, detecting that the first transceiver module has been swapped for a second transceiver module of a second transmission connection type; 
 receiving on the port signals having a format and encoding that is different depending on a whether a physical media used for a transmission connection to the port is optical or electrical; 
 setting a value of a register of the integrated circuit to correspond to whether a signal detect (SD) pin for the port is left floating which indicates that the transmission connection to the port is electrical;  
 monitoring the register of the integrated circuit to determine whether, due to the swap from the first transceiver module to the second transceiver module, the port has a the transmission connection to a transceiver module that is different than the port is configured and resetting the port when a value in the register has changed, wherein the port comprises a single transmission connection to the transceiver module which is configured for either optical or electrical transmission; 
 determining that the port has the second transmission connection type that is different than the port is configured; and 
 instructing the integrated circuit to reset the port to the transmission connection at the port to match the second transmission connection type. 
 
     
     
       2. The method of  claim 1 , wherein a signal detect (SD) signal on a pin on the port indicates whether the transmission connection is optical or electrical. 
     
     
       3. The method of claim  2  1, wherein the integrated circuit stores in a the register the values of the SD signal for each of the ports of the line card. 
     
     
       4. The method of  claim 3 , wherein the monitoring the integrated circuit comprises monitoring the register to detect changes in the register. 
     
     
       5. The method of  claim 1 , wherein the instructing the integrated circuit comprises sending an instruction to the integrated circuit to reset the port as is specified in a the register. 
     
     
       6. The method of  claim 5 , further comprising modifying the register to specify the port. 
     
     
       7. The method of  claim 1 , wherein the integrated circuit is designed to configure the transmission connection of each port of the line card at powerup. 
     
     
       8. The method of  claim 1 , wherein resetting the port changes a protocol utilized with signals from the transmission connection. 
     
     
       9. The method of  claim 8 , wherein the protocol is NRZI for optical or 3-Level MLT3 for electrical. 
     
     
       10. A computer program product for selecting optical or electrical transmissions on a port of a line card in a network device, the line card including an integrated circuit that supports optical and electrical transmissions, comprising:
 computer code that configures and specializes a processor to, at powerup of the line card of the network device, cause the integrated circuit to configure the port for a first transceiver module of a first transmission connection type connected to the line card; 
 computer code that configures and specializes the processor to, after powerup of the line card of the network device, detect that the first transceiver module has been swapped for a second transceiver module of a second transmission connection type; 
 computer code that configures and specializes the processor to cause the integrated circuit to receive on the port signals having a format and encoding that is different depending on a whether a physical media used for a transmission connection to the port is optical or electrical; 
 computer code that configures and specializes the processor to set a value of a register of the integrated circuit to correspond to whether a signal detect (SD) pin for the port is left floating which indicates that the transmission connection to the port is electrical;  
 computer code that configures a and specializes the processor to monitor the register of the integrated circuit to determine, due to the swap from the first transceiver module to the second transceiver module, whether the port has a the transmission connection to a transceiver module that is different than the port is configured and resetting the port when a value in the register has changed, wherein the port comprises a single transmission connection to the transceiver module which is configured for either optical or electrical transmission; 
 computer code that determines configures and specializes the processor to determine that the port has the second transmission connection type that is different than the port is configured; 
 computer code that configures a and specializes the processor to instruct the integrated circuit to reset the port to the transmission connection at the port to match the second transmission connection type; and 
 a computer readable medium that stores the computer codes. 
 
     
     
       11. An apparatus that selects optical or electrical transmissions on a port of a line card in a network device, the line card including an integrated circuit that supports optical and electrical transmissions, comprising:
 means for, at powerup of the line card of the network device, configuring the port for a first transceiver module of a first transmission connection type connected to the line card; 
 means for, after powerup of the line card of the network device, detecting that the first transceiver module has been swapped for a second transceiver module of a second transmission connection type; 
 means for receiving on the port signals having a format and encoding that is different depending on a whether a physical media used for a transmission connection to the port is optical or electrical; 
 means for setting a value of a register of the integrated circuit to correspond to whether a signal detect (SD) pin for the port is left floating which indicates that the transmission connection to the port is electrical;  
 means for monitoring the register of the integrated circuit to determine whether, due to the swap from the first transceiver module to the second transceiver module, the port has a the transmission connection to a transceiver module that is different than the port is configured and resetting the port when a value in the register has changed, wherein the port comprises a single transmission connection to the transceiver module which is configured for either optical or electrical transmission; 
 means for determining that the port has second transmission connection type that is different than the port is configured; and 
 means for instructing the integrated circuit to reset the port to the transmission connection at the port to match the second transmission connection type. 
 
     
     
       12. A line card for a network device that selects optical or electrical transmissions on a port of a line card in a network device, the line card including an integrated circuit that supports optical and electrical transmissions, comprising:
 computer code that configures and specializes a processor to, at powerup of the line card of the network device, cause the integrated circuit to configure the port for a first transceiver module of a first transmission connection type connected to the line card; 
 computer code that configures and specializes the processor to, after powerup of the line card of the network device, detect that the first transceiver module has been swapped for a second transceiver module of a second transmission connection type; 
 computer code that configures and specializes the processor to cause the integrated circuit to receive on the port signals having a format and encoding that is different depending on a whether a physical media used for a transmission connection to the port is optical or electrical; 
 computer code that configures and specializes the processor to set a value of a register of the integrated circuit to correspond to whether a signal detect (SD) pin for the port is left floating which indicates that the transmission connection to the port is electrical;  
 computer code that configures a and specializes the processor to monitor the register of the integrated circuit to determine, due to the swap from the first transceiver module to the second transceiver module, whether the port has a the transmission connection to a transceiver module that is different than the port is configured and resetting the port when a value in the register has changed, wherein the port comprises a single transmission connection to the transceiver module which is configured for either optical or electrical transmission; 
 computer code that determines configures and specializes the processor to determine that the port has the second transmission connection type that is different than the port is configured; 
 computer code that configures a and specializes the processor to instruct the integrated circuit to reset the port to the transmission connection at the port to match the second transmission connection type; and 
 a computer readable medium that stores the computer codes. 
 
     
     
       13. A method of selecting optical or electrical transmissions on a port of a line card in a network device, the line card including an integrated circuit that supports optical and electrical transmissions, comprising:
 at powerup of the line card of the network device, configuring the port for a first transceiver module of a first transmission connection type connected to the line card; 
 after powerup of the line card of the network device, detecting that the first transceiver module has been swapped for a second transceiver module of a second transmission connection type; 
 receiving on the port signals having a format and encoding that is different depending on a whether a physical media used for a transmission connection to the port is optical or electrical;  
 monitoring a first register of the integrated circuit to determine whether, due to the swap from the first transceiver module to the second transceiver module, the port has a the transmission connection to a transceiver module that is different than the port is configured and resetting the port when a value in the register has changed, wherein the port comprises a single transmission connection to the transceiver module which is configured for either optical or electrical transmission; 
 determining that the port has the second transmission connection type that is different than the port is configured; 
 modifying a second register of the integrated circuit to specify the port that has the transmission connection is changed to the second transmission connection type that is different than the first transmission connection type for which the port is configured, wherein modifying comprises setting a value of the second register to correspond to whether a signal detect (SD) pin for the port is left floating which indicates that the transmission connection for the port is electrical; and 
 instructing the integrated circuit to reset the port specified by the second register to the transmission connection at the port to match the second transmission connection type. 
 
     
     
       14. The method of  claim 13 , wherein a signal detect (SD) signal on a pin on the port indicates whether the transmission connection is optical or electrical. 
     
     
       15. The method of  claim 14 , wherein the integrated circuit stores in the first register the values of the SD signal for each of the ports of the line card. 
     
     
       16. The method of  claim 15 , wherein the monitoring the integrated circuit comprises monitoring the first register to detect changes in the first register. 
     
     
       17. The method of  claim 13 , wherein the integrated circuit is designed to configure the transmission connection of each port of the line card at powerup. 
     
     
       18. The method of  claim 13 , wherein resetting the port changes a protocol utilized with signals from the transmission connection. 
     
     
       19. The method of  claim 18 , wherein the protocol is NRZI for optical or 3-Level MLT3 for electrical. 
     
     
       20. A computer program product for selecting optical or electrical transmissions on a port of a line card in a network device, the line card including an integrated circuit that supports optical and electrical transmissions, comprising:
 computer code that configures and specializes a processor to, at powerup of the line card of the network device, cause the integrated circuit to configure the port for a first transceiver module of a first transmission connection type connected to the line card; 
 computer code that configures and specializes the processor to, after powerup of the line card of the network device, detect that the first transceiver module has been swapped for a second transceiver module of a second transmission connection type; 
 computer code that configures and specializes the processor to cause the integrated circuit to receive on the port signals having a format and encoding that is different depending on a whether a physical media used for a transmission connection to the port is optical or electrical;  
 computer code that configures a and specializes the processor to monitor a first register of the integrated circuit to determine whether, due to the swap from the first transceiver module to the second transceiver module, the port has a the transmission connection to a transceiver module that is different than the port is configured and resetting the port when a value in the first register has changed, wherein the port comprises a single transmission connection to the transceiver module which is configured for either optical or electrical transmission; 
 computer code that determines configures and specializes the processor to determine that the port has the second transmission connection type that is different than the port is configured; 
 computer code that configures a and specializes the processor to modify a second register of the integrated circuit to specify the port that has the transmission connection is changed to the second transmission connection type that is different than the first transmission connection type for which the port is configured by setting a value of the second register to correspond to whether a signal detect (SD) pin for the port is left floating which indicates that the transmission connection for the port is electrical; 
 computer code that configures a and specializes the processor to instruct the integrated circuit to reset the port specified by the second register to the transmission connection at the port to match the second transmission connection type; and 
 a computer readable medium that stores the computer codes. 
 
     
     
       21. An apparatus that selects optical or electrical transmissions on a port of a line card in a network device, the line card including an integrated circuit that supports optical and electrical transmissions, comprising:
 means for, at powerup of the line card of the network device, configuring the port for a first transceiver module of a first transmission connection type connected to the line card; 
 means for, after powerup of the line card of the network device, detecting that the first transceiver module has been swapped for a second transceiver module of a second transmission connection type; 
 means for receiving on the port signals having a format and encoding that is different depending on a whether a physical media used for a transmission connection to the port is optical or electrical;  
 means for monitoring a first register of the integrated circuit to determine whether, due to the swap from the first transceiver module to the second transceiver module, the port has a the transmission connection to a transceiver module that is different than the port is configured and resetting the port when a value in the register has changed, wherein the port comprises a single transmission connection to the transceiver module which is configured for either optical or electrical transmission; 
 means for determining that the port has the second transmission connection type that is different than the port is configured; 
 means for modifying a second register of the integrated circuit to specify the port that has the transmission connection is changed to the second transmission connection type that is different than the first transmission connection type for which the port is configured, wherein the means for modifying the second register comprises means for setting a value of the second register to correspond to whether a signal detect (SD) pin for the port is left floating which indicates that the transmission connection for the port is electrical; and 
 means for instructing the integrated circuit to reset the port specified by the second register to the transmission connection at the port to match the second transmission connection type. 
 
     
     
       22. A line card for a network device that selects optical or electrical transmissions on a port of a line card in a network device, the line card including an integrated circuit that supports optical and electrical transmissions, comprising:
 computer code that configures and specializes a processor to, at powerup of the line card of the network device, cause the integrated circuit to configure the port for a first transceiver module of a first transmission connection type connected to the line card; 
 computer code that configures and specializes the processor to, after powerup of the line card of the network device, detect that the first transceiver module has been swapped for a second transceiver module of a second transmission connection type; 
 computer code that configures and specializes the processor to cause the integrated circuit to receive on the port signals having a format and encoding that is different depending on a whether a physical media used for a transmission connection to the port is optical or electrical;  
 computer code that configures a and specializes the processor to monitor a first register of the integrated circuit to determine whether, due to the swap from the first transceiver module to the second transceiver module, the port has a the transmission connection to a transceiver module that is different than the port is configured and resetting the port when a value in the first register has changed, wherein the port comprises a single transmission connection to the transceiver module which is configured for either optical or electrical transmission; 
 computer code that determines configures and specializes a processor to determine that the port has the second transmission connection type that is different than the port is configured; 
 computer code that configures and specializes the processor to modify a second register of the integrated circuit to specify the port that has the transmission connection is changed to the second transmission connection type that is different than the first transmission connection type for which the port is configured by setting a value of the second register to correspond to whether a signal detect (SD) pin for the port is left floating which indicates that the transmission connection for the port is electrical; 
 computer code that configures and specializes the processor to instruct the integrated circuit to reset the port specified by the second register to the transmission connection at the port to match the second transmission connection type; and 
 a computer readable medium that stores the computer codes. 
 
     
     
       23. The method of claim 1, wherein the transceiver module is a small form-factor pluggable (SFP) module.  
     
     
       24. The method of claim 23, wherein the integrated circuit stores in the register the values of the SD pin for each of the ports of the line card.  
     
     
       25. The method of claim 24, wherein the monitoring the integrated circuit comprises monitoring the register to detect changes in the register.  
     
     
       26. The method of claim 23, wherein the instructing the integrated circuit comprises sending an instruction to the integrated circuit to reset the port as is specified in the register.  
     
     
       27. The method of claim 26, further comprising modifying the register to specify the port.  
     
     
       28. The method of claim 23, wherein the integrated circuit is designed to configure the transmission connection of each port of the line card at powerup.  
     
     
       29. The method of claim 23, wherein resetting the port changes a protocol utilized with signals from the transmission connection.  
     
     
       30. The method of claim 29, wherein the protocol is NRZI for optical or 3-Level MLT3 for electrical.  
     
     
       31. The computer program product of claim 10, wherein the transceiver module is a small form-factor pluggable (SFP) module.  
     
     
       32. The apparatus of claim 11, wherein the transceiver module is a small form-factor pluggable (SFP) module.  
     
     
       33. The line card of claim 12, wherein the transceiver module is a small form-factor pluggable (SFP) module.  
     
     
       34. The method of claim 13, wherein the transceiver module is a small form-factor pluggable (SFP) module.  
     
     
       35. The method of claim 34, wherein the integrated circuit stores in the first register the values of the SD pin for each of the ports of the line card.  
     
     
       36. The method of claim 35, wherein the monitoring the integrated circuit comprises monitoring the first register to detect changes in the first register.  
     
     
       37. The method of claim 34, wherein the integrated circuit is designed to configure the transmission connection of each port of the line card at powerup.  
     
     
       38. The method of claim 34, wherein resetting the port changes a protocol utilized with signals from the transmission connection.  
     
     
       39. The method of claim 38, wherein the protocol is NRZI for optical or 3-Level MLT3 for electrical.  
     
     
       40. The computer program product of claim 20, wherein the transceiver module is a small form-factor pluggable (SFP) module.  
     
     
       41. The apparatus of claim 21, wherein the transceiver module is a small form-factor pluggable (SFP) module.  
     
     
       42. The line card of claim 22, wherein the transceiver module is a small form-factor pluggable (SFP) module.