Providing an abstraction layer in a cluster switch that includes plural switches

• US 20090092043A1
• Filed: 10/03/2007
• Published: 04/09/2009
• Est. Priority Date: 10/03/2007
• Status: Active Grant

• Current Assignee: Avaya Incorporated
• Original Assignee: Nortel Networks Limited (Nortel Networks Corporation)
• Inventors: Anumala, Mohnish, Lariviere, Robert, Lapuh, Roger, Assarpour, Hamid, White, Martin L.
• Granted Patent: US 7,751,329 B2
• Time in Patent Office: Days
• US Class Current: 370/228
• CPC Class Codes: H04L 49/351 for local area network [LAN], e.g. Ethernet switches
• CPC Class Codes: H04L 49/552 by ensuring the integrity of packets received through redundant connections
• CPC Class Codes: H04L 49/555 Error detection
• CPC Class Codes: H04L 49/70 Virtual switches

Abstract

In a communications network, a cluster switch is provided, where the cluster switch has plural individual switches. An abstraction layer is provided in the cluster switch, such that an interface having a set of ports is provided to upper layer logic in the cluster switch. The set of ports includes a collection of ports of the individual switches. Control traffic and data traffic are communicated over virtual tunnels between individual switches of the cluster switch, where each virtual tunnel has an active channel and at least one standby channel.

Claims

1. A method for use in a communications network, comprising:

providing an abstraction layer in a virtual cluster switch having plural individual switches;

communicating control traffic and data traffic over virtual tunnels between individual switches of the cluster switch, wherein each virtual tunnel has an active channel and at least one standby channel; and

presenting, by the abstraction layer, an interface having a set of ports to upper layer logic in the cluster switch, wherein the set of ports includes a collection of ports of the individual switches.

2. The method of claim 1, wherein communicating the control traffic and data traffic over each virtual channel occurs over the corresponding active channel but not the corresponding at least one standby channel.

3. The method of claim 1, further comprising:

performing an integrity check of the active channel of a particular one of the virtual tunnels to detect failure of the active channel; and

in response to detecting failure of the active channel of the particular virtual tunnel, performing further communication of control traffic and data traffic over the at least one standby channel of the particular virtual tunnel.

4. The method of claim 1, further comprising defining a predefined priority order for the channels in each virtual tunnel.

5. The method of claim 4, further comprising selecting a first one of the channels in a particular one of the virtual tunnels as the active channel according to the predefined priority order.

6. The method of claim 5, further comprising:

in response to detecting failure of the first channel, selecting a second one of the channels of the particular virtual tunnel as the active channel according to the predefined priority order.

7. The method of claim 6, further comprising:

detecting restoration of the first channel; and

in response to the detecting the restoration, re-selecting the first channel as the active channel and designating the second channel as a standby channel.

8. The method of claim 1, wherein providing the abstraction layer comprises providing a master module in one of the individual switches, the master module managing the plural individual switches in the cluster switch.

9. The method of claim 1, further comprising connecting the cluster switch to plural clients over respective aggregated links, wherein each aggregated link includes at least two link members connected to different individual switches of the cluster switch.

10. The method of claim 9, further comprising:

receiving traffic from a first one of the clients at a first one of the individual switches in the cluster switch; and

forwarding, from the first individual switch, the traffic to each of other individual switches in the cluster switch.

11. The method of claim 9, further comprising:

receiving traffic from a first one of the clients at a particular one of the individual switches in the cluster switch;

determining, at the particular individual switch, whether the particular individual switch is coupled to a target client; and

in response to determining that the particular switch is coupled to the target client, the particular individual switch performing a table lookup to identify whether the received traffic is to be forwarded over a link member of an aggregated link coupling the particular individual to the target client.

12. The method of claim 1, further comprising:

communicating MAC-in-MAC packets over the virtual tunnels.

13. The method of claim 1, further comprising:

performing a two-tier destination lookup in each of the individual switches.

14. The method of claim 1, further comprising:

communicating at least one of internal switch fabric port status and external port status through the virtual tunnels.

15. A first switch comprising:

a control plane that is a master control plane for a cluster switch that includes plural individual switches, the plural individual switches including the first switch;

one or more data planes connected to respective virtual tunnels to peer individual switches in the cluster switch, wherein each virtual tunnel has an active channel over which traffic is communicated, and at least one standby channel over which traffic is not communicated,

wherein the master control plane defines a set of ports that includes a collection of ports of the individual switches.

16. The first switch of claim 15, wherein the master control plane defines an index for the set of ports that is a combination of ports of the individual switches, wherein the first switch further comprises:

upper protocol layer logic that is presented the index to allow the upper protocol layer logic to access the set of ports.

17. The first switch of claim 16, wherein a lower protocol layer infrastructure of the first switch including the infrastructure for the virtual tunnels is hidden from the upper protocol layer logic.

18. The first switch of claim 15, wherein the individual switches of the cluster switch are interconnected by physical links, and wherein a particular one of the virtual tunnels has a first channel that is defined on a first number of physical links, and a second channel that is defined on a second, different number of physical links.

19. An article comprising at least one computer-readable storage medium containing instructions that when executed cause at least one processor in a cluster switch to:

communicate traffic over virtual tunnels interconnecting individual switches of the cluster switch, wherein each virtual tunnel has an active channel and at least one standby channel;

define a master control plane in one of the individual switches to manage each of the individual switches of the cluster switch; and

detect for failures of channels in the virtual tunnels to allow for selection of alternate channels in response to detected failures.

20. The article of claim 19, wherein the instructions when executed cause the at least one processor of the master control plane presents a set of ports to upper protocol layer logic, wherein the set of ports is a collection of ports of the individual switches.