USAGE OF MASKED ETHERNET ADDRESSES BETWEEN TRANSPARENT INTERCONNECT OF LOTS OF LINKS (TRILL) ROUTING BRIDGES

• US 20120243539A1
• Filed: 05/31/2011
• Published: 09/27/2012
• Est. Priority Date: 03/21/2011
• Status: Active Grant

• Current Assignee: Extreme Networks, Inc.
• Original Assignee: Avaya Incorporated
• Inventors: Keesara, Srikanth
• Granted Patent: US 8,755,383 B2
• Time in Patent Office: Days
• US Class Current: 370/392
• CPC Class Codes: H04L 45/66 Layer 2 routing, e.g. in Ethernet based MAN's

Abstract

Techniques herein include systems and methods that extend functionality of transport networks including Transparent Interconnect of Lots of Links (TRILL) networks. Techniques include using a portion of information within transport device address encapsulation headers for purposes other than identifying source and destination device addresses. The system masks a portion of bits in an address header for an address lookup in forwarding tables of a transport network node. The remaining bits in the address field(s) become free bits that can be used for a variety of application purposes, such as flow identifier selection. By using information fields that already exist in encapsulation headers, such techniques provide additional information without increasing packet size or requiring new protocols. Embodiments can combine Equal-cost multi-path routing (ECMP) functionality, Reverse Path Forwarding (RPF) checks, and Time to live (TTL) protection at the same time.

Claims

1. A computer-implemented method for packet switching in a Transparent Interconnect of Lots of Links (TRILL) network, the computer-implemented method comprising:

receiving a data packet at a first data switching device, the data packet having an existing header and being received from a customer network, the first data switching device being an ingress RBridge of a TRILL network;

encapsulating the data packet using a TRILL header, the TRILL header having a data structure that includes a transport device address space and a TRILL device address space;

encapsulating the data packet includes setting a first portion of bits, within the transport device address space, such that the first portion of bits indicates a data switching device address that is a node within the TRILL network;

encapsulating the data packet includes setting a second portion of bits, within the transport device address space, such that the second portion of bits indicates information distinct from the data switching device address that is a node within the TRILL network;

encapsulating the data packet includes setting bits within TRILL device address spaces such that the bits indicate an ingress RBridge nickname and an egress RBridge nickname; and

forwarding the data packet via the TRILL network.

2. The computer-implemented method of claim 1, wherein encapsulating the data packet using the TRILL header includes encapsulating the data packet using an Ethernet header;

wherein encapsulating the data packet using the Ethernet header includes indicating, within the transport device address space, that the transport device address space uses locally administered Media Access Control addresses; and

wherein encapsulating the data packet using the Ethernet header includes indicating, within the transport device address space, that the data packet is a unicast transmission.

3. The computer-implemented method of claim 1, wherein the data structure of the TRILL header is an Ethernet header that includes a virtual local area network (VLAN) indicator space;

wherein encapsulating the data packet using the TRILL header includes encapsulating the data packet using the Ethernet header; and

wherein encapsulating the data packet using the Ethernet header includes indicating, within the VLAN indicator space, which bits of the transport device address space indicate the data switching device address, and which bits of the transport device address space indicate the information distinct from the data switching device address.

4. The computer-implemented method of claim 1, wherein setting a second portion of bits that indicates information distinct from the data switching device address includes indicating a User Network Interface (UNI) identity, the UNI identity indicating an interface that the data packet used to enter the TRILL network.

5. The computer-implemented method of claim 1, further comprising:

wherein setting the second portion of bits, within the transport device address space, that indicates information distinct from the data switching device address includes indicating a flow identifier;

selecting a next-hop forwarding path by using the flow identifier from the transport device address space as computational input for selecting the next-hop forwarding path; and

wherein forwarding the data packet via the TRILL network includes forwarding the data packet to a next-hop node within the TRILL network via the selected next-hop forwarding path.

6. The computer-implemented method of claim 1, further comprising:

wherein encapsulating the data packet includes setting a first portion of bits within the VLAN space, such that the first portion of bits within the VLAN space indicates a customer VLAN; and

wherein encapsulating the data packet includes setting a second portion of bits within the VLAN space, such that the second portion of bits within the VLAN space indicates a time to live (TTL) value of the data packet within the TRILL network.

7. The computer-implemented method of claim 1, encapsulating the data packet using the TRILL header includes encapsulating the data packet using an Ethernet header;

wherein the Ethernet header includes a Media Access Control (MAC) destination address space, and a Media Access Control (MAC) source address space; and

wherein encapsulating the data packet includes using bits from the MAC destination address space and from the MAC source address space such that the aggregate bits across the MAC destination address space and the MAC source address space indicate information distinct from data switching device addresses.

8. A computer program product including a non-transitory computer-storage medium having instructions stored thereon for processing data information, such that the instructions, when carried out by a processing device, cause the processing device to perform the operations of:

receiving a data packet at a first data switching device, the data packet having an existing header and being received from a customer network, the first data switching device being an ingress RBridge of a TRILL network;

encapsulating the data packet using a TRILL header, the TRILL header having a data structure that includes a transport device address space and a TRILL device address space;

encapsulating the data packet includes setting a first portion of bits, within the transport device address space, such that the first portion of bits indicates a data switching device address that is a node within the TRILL network;

encapsulating the data packet includes setting a second portion of bits, within the transport device address space, such that the second portion of bits indicates information distinct from the data switching device address that is a node within the TRILL network;

encapsulating the data packet includes setting bits within TRILL device address spaces such that the bits indicate an ingress RBridge nickname and an egress RBridge nickname; and

forwarding the data packet via the TRILL network.

9. A computer-implemented method for packet switching in a Transparent Interconnect of Lots of Links (TRILL) network, the computer-implemented method comprising:

receiving a data packet at an RBridge device within a TRILL network, the data packet received from another node within the TRILL network, the data packet having a customer network header encapsulated by a TRILL header, the TRILL header including transport device address spaces and RBridge nickname spaces;

identifying a transport device address from a transport device address space within the TRILL header, the transport device address space having a first portion of bits that indicates a transport device address of a first data switching device, and the transport device address space having a second portion of bits that indicates information distinct from the transport device address of the first data switching device;

executing a lookup in a forwarding table of the RBridge device based on the transport device address indicated in the first portion of bits;

replacing the first portion of bits, that indicates the transport device address of the first data switching device address, with bits that indicate a second data switching device address while maintaining the second portion of bits unchanged; and

forwarding the data packet via the TRILL network.

10. The computer-implemented method of claim 9, wherein executing the lookup includes masking the second portion of bits within the transport device address space prior to executing the lookup.

11. The computer-implemented method of claim 9, wherein executing the lookup includes identifying the first portion of bits that indicates the transport device address of a first data switching device based on information from a virtual local area network (VLAN) indicator space of the TRILL header.

12. The computer-implemented method of claim 9, wherein the transport device address space indicates that the transport device address space uses locally administered Media Access Control (MAC) addresses that are unicast addresses, the transport device address space being an Ethernet header Media Access Control address space having 48 available bits.

13. The computer-implemented method of claim 9, further comprising:

selecting a forwarding path by executing a hashing operation using a flow identifier as computational input for the hashing operation, the flow identifier indicated within the second portion of the transport device address space; and

wherein forwarding the data packet via the TRILL network includes forwarding the data packet to a next-hop node within the TRILL network via the selected forwarding path.

14. The computer-implemented method of claim 9, wherein the data packet encapsulated by the TRILL header includes the data packet using an Ethernet header that includes a Media Access Control (MAC) destination address space, and a Media Access Control (MAC) source address space, the Ethernet header using bits across both the MAC destination address space and the MAC source address space to indicate information distinct from the data switching device addresses.

15. A computer-implemented method for packet switching in a transport network, the computer-implemented method comprising:

receiving a data packet at a first data switching device, the data packet having an existing header and being received from a customer network, the first data switching device being an edge node of a transport network;

encapsulating the data packet using a transport network header, the transport network header having a data structure that includes a transport device address space and a virtual local area network (VLAN) indicator space;

encapsulating the data packet includes setting a first portion of bits within the transport device address space, such that the first portion of bits indicates a data switching device address that is a node within the transport network;

encapsulating the data packet includes setting a second portion of bits within the transport device address space, such that the second portion of bits indicates a flow identifier;

selecting a forwarding path to a next-hop node of the transport network by using the flow identifier from the transport device address space as computational input for selecting the forwarding path; and

forwarding the data packet to the next-hop node in the transport network using the selected forwarding path.

16. The computer-implemented method of claim 15, further comprising:

generating the flow identifier by using packet information from the existing header as computational input for generating the flow identifier.

17. The computer-implemented method of claim 16, wherein generating the flow identifier includes generating a hashing index on customer information identified within the existing header.

18. The computer-implemented method of claim 17, wherein encapsulating the data packet includes setting a third portion of bits, within the transport device address space, such that the third portion of bits indicates a time to live (TTL) value of the data packet.

19. The computer-implemented method of claim 16, further comprising:

wherein encapsulating the data packet includes setting a first portion of bits within the VLAN space, such that the first portion of bits within the VLAN space indicates a customer VLAN; and

wherein encapsulating the data packet includes setting a second portion of bits within the VLAN space, such that the second portion of bits within the VLAN space indicates a time to live (TTL) of the data packet.

20. The computer-implemented method of claim 15, further comprising:

wherein the transport network header is an Ethernet header that includes a Backbone Media Access Control (MAC) destination address space, and a Backbone Media Access Control source address space;

wherein encapsulating the data packet includes using bits from the Backbone MAC destination address space and the Backbone MAC source address space to indicate the flow identifier;

wherein encapsulating the data packet using the Ethernet header includes indicating, within the Backbone MAC space, that the transport device address space uses locally administered Media Access Control addresses; and

wherein the transport network is a Provider Backbone Bridge (PBB) network.

21. A computer program product including a non-transitory computer-storage medium having instructions stored thereon for processing data information, such that the instructions, when carried out by a processing device, cause the processing device to perform the operations of:

receiving a data packet at a first data switching device, the data packet having an existing header and being received from a customer network, the first data switching device being an edge node of a transport network;

encapsulating the data packet using a transport network header, the transport network header having a data structure that includes a transport device address space and a virtual local area network (VLAN) indicator space;

encapsulating the data packet includes setting a first portion of bits within the transport device address space, such that the first portion of bits indicates a data switching device address that is a node within the transport network;

encapsulating the data packet includes setting a second portion of bits within the transport device address space, such that the second portion of bits indicates a flow identifier;

selecting a forwarding path to a next-hop node of the transport network by using the flow identifier from the transport device address space as computational input for selecting the forwarding path; and

forwarding the data packet to the next-hop node in the transport network using the selected forwarding path.

22. A computer-implemented method for packet switching in a transport network, the computer-implemented method comprising:

receiving a data packet at a data switching device, the data switching device being a node within a transport network, the data packet received from another node within the transport network, the data packet having a customer network header encapsulated by a transport network header;

identifying a transport device address from a transport device address space within the transport network header, the transport device address space having a first portion of bits that indicates a data switching device address of a second data switching device, and the transport device address space having a second portion of bits that indicates a flow identifier;

executing a lookup, in a forwarding table of the data switching device, based on the data switching device address indicated in the first portion of bits;

selecting a forwarding path to a next-hop node in the transport network by using the flow identifier from the transport device address space as computational input for selecting the forwarding path; and

forwarding the data packet to the next-hop node in the transport network using the selected forwarding path.

23. The computer-implemented method of claim 22, further comprising:

wherein executing the lookup in the forwarding table of the data switching device includes executing a reverse path forwarding (RPF) check, the RPF check comprising;

discarding the data packet in response to identifying that the data packet was received from an interface that does not match any incoming interface on a list of expected incoming interfaces for the data switching device in the transport network.

24. The computer-implemented method of claim 23, wherein the data packet includes a third portion of bits within the transport device address space, the third portion of bits within the transport device address space indicating a time to live (TTL) value of the data packet;

and

decrementing the TTL value indicated within the transport device address space.

25. The computer-implemented method of claim 24, wherein selecting the forwarding path to a next-hop node includes providing Equal-cost multi-path routing (ECMP) using the using the flow identifier indicated by the a second portion of bits in the transport device address space.