Transmitting and Forwarding Data

• US 20130232277A1
• Filed: 08/30/2012
• Published: 09/05/2013
• Est. Priority Date: 08/31/2011
• Status: Active Grant

• Current Assignee: Metaswitch Networks Limited (Microsoft Corporation)
• Original Assignee: Metaswitch Networks Limited (Microsoft Corporation)
• Inventors: Williams, Matthew
• Granted Patent: US 9,246,796 B2
• Time in Patent Office: Days
• US Class Current: 709/239
• CPC Class Codes: H04L 45/22 Alternate routing
• CPC Class Codes: H04L 45/28 using route fault recovery

Abstract

A network comprises a communication device having network communication interfaces and a data processing node having network communication ports. The communication device includes a first and a second interface communicatively coupled to a first and a second port of the data processing node respectively. The first interface is selected as a primary interface for the transmission of network traffic to destinations across the network. The second interface is selected as a backup interface which is to be selected for the transmission of the network traffic in the case of a need to failover to the backup interface. Network traffic from the communication device is transmitted via the first interface while the first interface is selected as the primary interface. At least one data message is transmitted from the communication device via the second interface, while the first interface is selected as the primary interface.

Claims

1. A method of transmitting data in a network, the network including a communication device having a plurality of network communication interfaces, and a data processing node having a plurality of network communication ports, the data processing node being arranged to select a forwarding port on which to forward data destined for a given communication device, the forwarding port being selected on the basis of a port on which it receives data from the given communication device, the data processing node being arranged to select a preferred forwarding port in the case of receipt of data from the given communication device on more than one of the plurality of ports, wherein the communication device includes a first interface communicatively coupled to a first port of the data processing node and a second interface communicatively coupled to a second port of the data processing node, the method comprising:

selecting the first interface as a primary interface for the transmission of network traffic to destinations across the network, and the second interface as a backup interface which is to be selected for the transmission of the network traffic in the case of a need to failover to the backup interface;

while the first interface is selected as the primary interface, transmitting network traffic from the communication device via the first interface; and

while the first interface is selected as the primary interface, transmitting at least one data message from the communication device via the second interface, in order to enable the selection by the data processing node of the second port as the preferred forwarding port for the communication device in the event of the network traffic being received at the first port of the data processing node.

2. The method according to claim 1, further comprising while the first interface is selected as the primary interface, intermittently transmitting at least one data message from the communication device via the second interface.

3. The method according to claim 1, further comprising setting a message destination identifier of the data messages to be the same as a message source identifier of the data messages, to allow the data processing node to recognise that the data messages are intended for processing only by the data processing node.

4. The method according to claim 1, further comprising setting a message destination identifier of the data messages to be an identifier reserved for data messages that are for processing only by the data processing node, to allow the data processing node to recognise that the data messages are intended for processing only by the data processing node.

5. The method according to claim 1, wherein the data processing node is arranged to deselect the second port as the preferred forwarding port for the communication device if no data is received from the communication device via the second port for a period of time, and wherein the method further comprises intermittently transmitting the data messages at time intervals which are less than the period of time.

6. The method according to claim 1, further comprising:

comparing at least one connectivity condition associated with the coupling between the first interface and the first port of the data processing node and at least one connectivity condition associated with the coupling between the second interface and the second port of the data processing node; and

selecting the first interface as the primary interface for the transmission of network traffic to destinations across the network on the basis of the comparison.

7. The method according to claim 1, wherein the first interface of the communication device is indirectly coupled to the first port of the data processing node via at least one intermediate network node and wherein the second interface of the communication device is directly coupled to the second port of the data processing node.

8. The method according to claim 1, wherein at least some of the data messages comprise Address Resolution Protocol (ARP) messages, Neighbour Discovery Protocol (NDP) messages and/or Internet Control Message Protocol (ICMP) ping messages.

9. A method of forwarding data in a network, the network including a communication device having a plurality of network communication interfaces, and a data processing node having a plurality of network communication ports, the data processing node being arranged to select a forwarding port on which to forward data destined for a given communication device, the forwarding port being selected on the basis of a port on which it receives data from the given communication device, the data processing node being arranged to select a preferred forwarding port in the case of receipt of data from the given communication device on more than one of the plurality of ports, wherein the data processing node includes a first port communicatively coupled to a first interface of the communication device and a second port communicatively coupled to a second interface of the communication device, the method comprising:

receiving network traffic from the communication device via the first port;

receiving at least one data message from the communication device via the second port;

receiving network traffic destined for the communication device; and

while receiving the network traffic from the communication device via the first port, maintaining selection of the second port as the preferred forwarding port for the network traffic destined for the communication device, on the basis of the data messages received via the second port.

10. The method according to claim 9, further comprising intermittently receiving data messages from the communication device via the second port.

11. The method according to claim 9, wherein the first port has a first preference rank and the second port has a second preference rank, and wherein the method further comprises determining that the second port should be selected as the preferred forwarding port on the basis of comparing the first and second preference ranks.

12. The method according to claim 9, wherein the data processing node is arranged to deselect the second port as the preferred forwarding port for the communication device, if no data is received from the communication device via the second port for a period of time.

13. The method according to claim 12, further comprising intermittently receiving the data messages at time intervals which are less than the period of time.

14. The method according to claim 9, further comprising deselecting the second port as the preferred forwarding port for the communication device in response to detecting the occurrence of a fault in relation to the coupling between the second port and the second interface of the communication device.

15. The method according to claim 9, further comprising:

recognising that the data messages are intended for processing only by the data processing node; and

discarding the data messages without forwarding to other network nodes following the selection of the second port as the preferred forwarding port.

16. The method according to claim 15, further comprising recognising that a message destination identifier in the data messages is the same as a message source identifier in the data messages.

17. The method according to claim 15, further comprising recognising that a message destination identifier in the data messages is reserved for data messages for processing only by the data processing node.

18. A communication device for transmitting data in a network, the network including a data processing node having a plurality of network communication ports, the data processing node being arranged to select a forwarding port on which to forward data destined for a given communication device, the forwarding port being selected on the basis of a port on which it receives data from the given communication device, the data processing node being arranged to select a preferred forwarding port in the case of receipt of data from the given communication device on more than one of the plurality of ports, wherein the communication device includes a first interface communicatively coupled to a first port of the data processing node and a second interface communicatively coupled to a second port of the data processing node, and wherein the communication device is arranged:

to select the first interface as a primary interface for the transmission of network traffic to destinations across the network, and the second interface as a backup interface which is to be selected for the transmission of the network traffic in the case of a need to failover to the backup interface;

while the first interface is selected as the primary interface, to transmit network traffic via the first interface; and

while the first interface is selected as the primary interface, to transmit at least one data message via the second interface, in order to enable the selection by the data processing node of the second port as the preferred forwarding port for the communication device in the event of the network traffic being received at the first port of the data processing node.

19. A data processing node for forwarding data in a network, the network including a communication device having a plurality of network communication interfaces, wherein the data processing node has a plurality of network communication ports, the data processing node being arranged to select a forwarding port on which to forward data destined for a given communication device, the forwarding port being selected on the basis of a port on which it receives data from the given communication device, the data processing node being arranged to select a preferred forwarding port in the case of receipt of data from the given communication device on more than one of the plurality of ports, and wherein the data processing node includes a first port which is arranged to be communicatively coupled to a first interface of the communication device and a second port which is arranged to be communicatively coupled to a second interface of the communication device, the data processing node being arranged:

to receive network traffic from the communication device via the first port;

to receive at least one data message from the communication device via the second port;

to receive network traffic destined for the communication device; and

to maintain selection of the second port as the preferred forwarding port for the network traffic destined for the communication device, on the basis of the data messages received via the second port.

20. A computer program product comprising a non-transitory computer-readable storage medium having computer readable instructions stored thereon, the computer readable instructions being executable by a computerized device to cause the computerized device to perform a method for transmitting data in a network, the network including a communication device having a plurality of network communication interfaces, and a data processing node having a plurality of network communication ports, the data processing node being arranged to select a forwarding port on which to forward data destined for a given communication device, the forwarding port being selected on the basis of a port on which it receives data from the given communication device, the data processing node being arranged to select a preferred forwarding port in the case of receipt of data from the given communication device on more than one of the plurality of ports, wherein the communication device includes a first interface communicatively coupled to a first port of the data processing node and a second interface communicatively coupled to a second port of the data processing node, the method comprising:

selecting the first interface as a primary interface for the transmission of network traffic to destinations across the network, and the second interface as a backup interface which is to be selected for the transmission of the network traffic in the case of a need to failover to the backup interface;

while the first interface is selected as the primary interface, transmitting network traffic from the communication device via the first interface; and

while the first interface is selected as the primary interface, transmitting at least one data message from the communication device via the second interface, in order to enable the selection by the data processing node of the second port as the preferred forwarding port for the communication device in the event of the network traffic being received at the first port of the data processing node.

21. A computer program product comprising a non-transitory computer-readable storage medium having computer readable instructions stored thereon, the computer readable instructions being executable by a computerized device to cause the computerized device to perform method of forwarding data in a network, the network including a communication device having a plurality of network communication interfaces, and a data processing node having a plurality of network communication ports, the data processing node being arranged to select a forwarding port on which to forward data destined for a given communication device, the forwarding port being selected on the basis of a port on which it receives data from the given communication device, the data processing node being arranged to select a preferred forwarding port in the case of receipt of data from the given communication device on more than one of the plurality of ports, wherein the data processing node includes a first port communicatively coupled to a first interface of the communication device and a second port communicatively coupled to a second interface of the communication device, the method comprising:

receiving network traffic from the communication device via the first port;

receiving at least one data message from the communication device via the second port

receiving network traffic destined for the communication device; and

while receiving the network traffic from the communication device via the first port, maintaining selection of the second port as the preferred forwarding port for the network traffic destined for the communication device, on the basis of the data messages received via the second port.