Express header for packets with hierarchically structured variable-length identifiers

• US 9,401,864 B2
• Filed: 10/31/2013
• Issued: 07/26/2016
• Est. Priority Date: 10/31/2013
• Status: Active Grant

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Palo Alto Research Center, Inc. (Xerox Holdings Corp.)
• Inventors: Solis, Ignacio, Mosko, Marc E.
• Primary Examiner(s): Dalencourt, Yves
• Application Number:
  US14/069,251
• Publication Number:
  US 20150120895A1
• Time in Patent Office: 999 Days
• Field of Search: None
• US Class Current: 1/1
• CPC Class Codes: H04L 45/00 Routing or path finding of packets in data switching networks routing or path finding in wireless networks H04W40/00
• CPC Class Codes: H04L 45/74 Address processing for routing
• CPC Class Codes: H04L 45/7453 using hashing
• CPC Class Codes: H04L 45/748 using longest matching prefix

Abstract

One embodiment of the present invention provides a system for forwarding named packets. During operation, the system receives a named packet with an express header. The named packet includes a payload and a name which identifies the payload. The express header includes a content identifier, a global forwarding identifier, and a local forwarding identifier. The content identifier uniquely represents an interest corresponding to the name. The global forwarding identifier includes forwarding information to facilitate global forwarding. The local forwarding identifier includes forwarding information to facilitate local forwarding. The system then makes a forwarding decision for the packet based on the content identifier, the global forwarding identifier, and optionally the local forwarding identifier.

Claims

1. A computer-executable method for forwarding named packets, the method comprising:

receiving, at a router within a network domain, a named packet with an express header, wherein the named packet includes a payload and a name which identifies the payload, wherein the name is a hierarchically structured variable-length identifier (HSVLI) comprising contiguous name components ordered from a most general level to a most specific level; and

wherein the express header includes a content identifier, a global forwarding identifier, and a local forwarding identifier;

wherein the content identifier is a hash derived based on the entire name and optionally additional information in the named packet, and the content identifier uniquely represents an interest corresponding to the name;

wherein the global forwarding identifier is different from the name and includes forwarding information to facilitate global forwarding of the named packet towards the network domain;

wherein the local forwarding identifier is different from the name and includes forwarding information to facilitate local forwarding of the named packet towards a destination node within the network domain,

wherein global forwarding is forwarding of the named packet towards the network domain, and local forwarding is forwarding of the named packet within the network domain towards the destination node;

determining whether the router is in the same network domain indicated by the global forwarding identifier; and

in response to determining that the router is in the network domain indicated by the global forwarding identifier, making a forwarding decision for the named packet based on the content identifier and the local forwarding identifier.

2. The method of claim 1, further comprising receiving a second named packet with a second express header that includes a second content identifier, a second global forwarding identifier, and a second local forwarding identifier, wherein the second named packet includes a second payload and a second name which identifies the second payload, and wherein the second name is one of:

a set of attributes,

a flat identifier,

an array of bytes,

an entire set of data, and

a portion of the data.

3. The method of claim 1, wherein the named packet is an interest in a piece of content corresponding to the name;

and

wherein the global forwarding identifier is a hash derived on the subset of the name components.

4. The method of claim 1, further comprising obtaining the global forwarding identifier from a node providing a directory service.

5. The method of claim 1, further comprising computing the global forwarding identifier based on the name or content of the named packet.

6. The method of claim 1, further comprising computing the local forwarding identifier based on the name or content of the named packet.

7. The method of claim 1, wherein the method further comprises computing the global forwarding identifier by hashing a predetermined number of components of the HSVLI or a number of components of the HSVLI based on each component'"'"'s type.

8. The method of claim 1, wherein the method further comprises computing the local forwarding identifier by hashing a predetermined number of components of the HSVLI or a number of components of the HSVLI based on each component'"'"'s type.

9. The method of claim 1, further comprising maintaining a pending interest table, wherein a respective entry in the pending interest table indicates a pending interest associated with the content identifier, global forwarding identifier, and local forwarding identifier.

10. The method of claim 1, further comprising maintaining a forwarding information base, wherein a respective entry in the forwarding information base indicates forwarding information for a named packet that contains a global forwarding identifier.

11. The method of claim 10, wherein the entry in the forwarding information base further indicates that local forwarding information exists corresponding to the named packet'"'"'s local forwarding identifier.

12. The method of claim 1, wherein the named packet is an interest in the piece of content;

and

wherein the method further comprises searching a local content store for content corresponding to the interest based on the content identifier and optionally the global forwarding identifier and local forwarding identifier.

13. A system for forwarding named packets, the system comprising:

a processor; and

a storage device coupled to the processor and storing instructions which when executed by the processor cause the processor to perform a method, the method comprising;

receiving, at a router within a network domain, a named packet with an express header, wherein the named packet includes a payload and a name which identifies the payload, wherein the name is a hierarchically structured variable-length identifier comprising contiguous name components ordered from a most general level to a most specific level; and

wherein the express header includes a content identifier, a global forwarding identifier, and a local forwarding identifier;

wherein the content identifier is a hash derived based on the entire name and optionally additional information in the named packet, and the content identifier uniquely represents an interest corresponding to the name;

wherein the global forwarding identifier is different from the name and includes forwarding information to facilitate global forwarding of the named packet towards the network domain;

wherein the local forwarding identifier is different from the name and includes forwarding information to facilitate local forwarding of the named packet towards a destination node within the network domain,

wherein global forwarding is forwarding of the named packet towards the network domain, and local forwarding is forwarding of the named packet within the network domain towards the destination node;

determining whether the router is in the same network domain indicated by the global forwarding identifier; and

in response to determining that the router is in the network domain indicated by the global forwarding identifier, making a forwarding decision for the named packet based on the content identifier and the local forwarding identifier.

14. The system of claim 13, further comprising receiving a second named packet with a second express header that includes a second content identifier, a second global forwarding identifier, and a second local forwarding identifier, wherein the second named packet includes a second payload and a second name which identifies the second payload, and wherein the second name is one of:

a set of attributes,

a flat identifier,

an array of bytes,

an entire set of data, and

a portion of the data.

15. The system of claim 13, wherein the named packet is an interest in a piece of content corresponding to the name;

wherein the content identifier is a hash derived based on the entire name and optionally additional information in the named packet; and

wherein the global forwarding identifier is a hash derived on the subset of the name components.

16. The system of claim 13, wherein the method further comprises obtaining the global forwarding identifier from a node providing a directory service.

17. The system of claim 13, wherein the method further comprises computing the global forwarding identifier based on the name or content of the named packet.

18. The system of claim 13, wherein the method further comprises computing the local forwarding identifier based on the name or content of the named packet.

19. The system of claim 13, wherein the method further comprises computing the global forwarding identifier by hashing a predetermined number of components of the HSVLI or a number of components of the HSVLI based on each component'"'"'s type.

20. The system of claim 13, wherein the method further comprises computing the local forwarding identifier by hashing a predetermined number of components of the HSVLI or a number of components of the HSVLI based on each component'"'"'s type.

21. The system of claim 13, wherein the method further comprises maintaining a pending interest table, wherein a respective entry in the pending interest table indicates a pending interest associated with the content identifier, global forwarding identifier, and local forwarding identifier.

22. The system of claim 13, wherein the method further comprises maintaining a forwarding information base, wherein a respective entry in the forwarding information base indicates forwarding information for a named packet that contains a global forwarding identifier.

23. The system of claim 22, wherein the entry in the forwarding information base further indicates that local forwarding information exists corresponding to the named packet'"'"'s local forwarding identifier.

24. The system of claim 13, wherein the named packet is an interest in the piece of content;

and

wherein the method further comprises searching a local content store for content corresponding to the interest based on the content identifier and optionally the global forwarding identifier and local forwarding identifier.

25. A non-transitory storage medium storing instructions which when executed by the processor cause a processor to perform a method for forwarding named packets, the method comprising:

receiving, at a router within a network domain, a named packet with an express header, the named packet includes a payload and a name which identifies the payload, wherein the name is a hierarchically structured variable-length identifier comprising contiguous name components ordered from a most general level to a most specific level; and

wherein the express header includes a content identifier, a global forwarding identifier, and a local forwarding identifier;

wherein the content identifier is a hash derived based on the entire name and optionally additional information in the named packet, and the content identifier uniquely represents an interest corresponding to the name;

wherein the global forwarding identifier is different from the name and includes forwarding information to facilitate global forwarding of the named packet towards the network domain;

wherein the local forwarding identifier is different from the name and includes forwarding information to facilitate local forwarding of the named packet towards a destination node within the network domain,

wherein global forwarding is forwarding of the named packet towards the network domain, and local forwarding is forwarding of the named packet within the network domain towards the destination node;

determining whether the router is in the same network domain indicated by the global forwarding identifier; and

in response to determining that the router is in the network domain indicated by the global forwarding identifier, making a forwarding decision for the named packet based on the content identifier and the local forwarding identifier.