Adaptive multi-interface use for content networking

• US 9,686,194 B2
• Filed: 12/23/2014
• Issued: 06/20/2017
• Est. Priority Date: 10/21/2009
• Status: Active Grant

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Thornton, James D., Jacobson, Van L.
• Primary Examiner(s): SMITH, MARCUS
• Application Number:
  US14/581,817
• Publication Number:
  US 20150113163A1
• Time in Patent Office: 910 Days
• CPC Class Codes: G06F 16/95 Retrieval from the web
• CPC Class Codes: H04L 45/12 Shortest path evaluation
• CPC Class Codes: H04L 45/54 Organization of routing tables
• CPC Class Codes: H04L 45/70 Routing based on monitoring results
• CPC Class Codes: H04L 45/745 Address table lookup; Address filtering
• CPC Class Codes: H04L 45/748 using longest matching prefix
• CPC Class Codes: H04L 61/4511 using domain name system [DNS]
• CPC Class Codes: H04L 67/63 Routing a service request depending on the request content or context
• CPC Class Codes: H04L 69/22 Parsing or analysis of headers

Abstract

One embodiment provides a system that forwards a packet with a hierarchically structured variable-length identifier (HSVLI) in a network. An HSVLI indicates a piece of content and indicates a hierarchical structure of contiguous components ordered from a most general level to a most specific level. The length of the HSVLI is not fixed. During operation, the system receives a packet which contains an interest for a piece of content with an HSVLI. Subsequently, the system determines forwarding information for the HSVLI based on one or more of: knowledge of content which matches the HSVLI, a forwarding policy, and contextual information about the network. Next, the system configures a forwarding engine with the forwarding information. The system then forwards the packet based on the forwarding information.

Claims

1. A computer-implemented method for forwarding a packet with a hierarchically structured variable-length identifier (HSVLI) in a network, comprising:

performing a lookup for a packet based on an HSVLI in a local forwarding information base (FIB) to determine forwarding information for the packet, wherein the packet comprises an interest for a piece of content expressed using the HSVLI;

wherein the HSVLI indicates the content and is hierarchically structured, and comprises contiguous components ordered from a most general level to a most specific level, and wherein the length of a respective HSVLI is not fixed;

in response to not finding a match for the HSVLI in the local FIB;

determining, by a connectivity agent, a forwarding decision and the forwarding information for the HSVLI; and

configuring an entry in the FIB to contain the HSVLI associated with the determined forwarding decision and forwarding information;

forwarding the packet based on the forwarding information; and

in response to receiving a second packet containing at least a prefix of the HSVLI and to identifying, via a second lookup in the local FIB that the HSVLI is a longest match for the prefix having a largest number of matched name components, forwarding the second packet based on the forwarding information.

2. The method of claim 1, wherein the forwarding decision includes selecting one or more local interfaces for forwarding the packet.

3. The method of claim 1, wherein the forwarding decision and the forwarding information are determined based on one or more of:

knowledge of content which matches the HSVLI, a forwarding policy, and contextual information.

4. The method of claim 1, further comprising:

determining a local interface to be a lower-latency interface among a plurality of local interfaces; and

selecting the local interface for forwarding packets comprising subsequent interests expressed using respective HSVLIs.

5. The method of claim 1, wherein one or more components of the HSVLI comprise a domain name system (DNS) name;

and

wherein the method further comprises;

identifying an Internet Protocol (IP) address mapped to the DNS name; and

establishing a tunnel to the identified IP address.

6. The method of claim 1, wherein the interest is further for a second piece of content, wherein the piece of content and the second piece of content are from two different namespaces.

7. The method of claim 6, further comprising pulling the piece of content and the second piece of content from the two different namespaces via two different local interfaces.

8. The method of claim 1, further comprising:

monitoring for changes in one or more of;

knowledge of content which matches the HSVLI, a forwarding policy, and contextual information; and

in response to observing a change in the knowledge of content, forwarding policy, or contextual information, and further in response to finding a match for the HSVLI in the local FIB during the lookup, re-determining the forwarding decision for the HSVLI based on the observed change.

9. The method of claim 8, further comprising selecting an interface from a set of matched interfaces for forwarding the packet based on one or more rules for choosing among multiple interfaces.

10. An apparatus for forwarding a packet with a hierarchically structured variable-length identifier (HSVLI) in a network comprising:

a processor;

a memory;

a determining mechanism configured to perform a lookup for a packet based on an HSVLI in a local forwarding information base (FIB) to determine forwarding information for the packet, wherein the packet comprises an interest for a piece of content expressed using the HSVLI;

wherein the HSVLI indicates the content and is hierarchically structured, and comprises contiguous components ordered from a most general level to a most specific level, and wherein the length of a respective HSVLI is not fixed;

a configuring mechanism, in response to the determining mechanism not finding a match for the HSVLI in the local FIB, configured to;

determine a forwarding decision and the forwarding information for the HSVLI; and

configure an entry in the local FIB to contain the HSVLI associated with the determined forwarding decision and forwarding information; and

a forwarding mechanism configured to forward the packet based on the forwarding information;

wherein the forwarding mechanism is further configured, in response to receiving a second packet containing at least a prefix of the HSVLI and to identifying, via a second lookup in the local FIB that the HSVLI is a longest match for the prefix having a largest number of matched name components, to forward the second packet based on the forwarding information.

11. The apparatus of claim 10, wherein the forwarding decision includes selecting one or more local interfaces for forwarding the packet.

12. The apparatus of claim 10, wherein the configuring mechanism determines the forwarding decision and the forwarding information based on one or more of:

knowledge of content which matches the HSVLI, a forwarding policy, and contextual information.

13. The apparatus of claim 10, wherein the determining mechanism is further configured to:

determine a local interface to be a lower-latency interface among a plurality of local interfaces; and

select the local interface for forwarding packets comprising subsequent interests expressed using respective HSVLIs.

14. The apparatus of claim 10, further configured to establish a tunnel to an Internet Protocol (IP) address, wherein one or more components of the HSVLI comprise a domain name system (DNS) name, and wherein the IP address is mapped to the DNS name.

15. The apparatus of claim 10, wherein the interest is further for a second piece of content, wherein the piece of content and the second piece of content are from two different namespaces.

16. The apparatus of claim 15, further configured to pull the piece of content and the second piece of content from the two different namespaces via two different local interfaces.

17. The apparatus of claim 10, further configured to:

monitor for changes in one or more of;

knowledge of content which matches the HSVLI, a forwarding policy, and contextual information; and

re-determine the forwarding decision for the HSVLI in response to observing a change in the knowledge of content, forwarding policy, or contextual information, and further in response to the determining mechanism finding a match for the HSVLI in the local FIB during the lookup, wherein the re-determination is based on the observed change.

18. The apparatus of claim 17 further configured to select an interface from a set of matched interfaces for forwarding the packet based on one or more rules for choosing among multiple interfaces.

19. A non-transitory computer-readable storage device storing instructions that when executed by a computer cause the computer to perform a method for forwarding a packet with a hierarchically structured variable-length identifier (HSVLI) in a network, the method comprising:

performing a lookup for a packet based on an HSVLI in a local forwarding information base (FIB) to determine forwarding information for the packet, wherein the packet comprises an interest for a piece of content expressed using the HSVLI;

wherein the HSVLI indicates the content and is hierarchically structured, and comprises contiguous components ordered from a most general level to a most specific level, and wherein the length of a respective HSVLI is not fixed;

in response to not finding a match for the HSVLI in the local FIB;

determining a forwarding decision and the forwarding information for the HSVLI; and

configuring an entry in the FIB to contain the HSVLI associated with the determined forwarding decision and forwarding information;

forwarding the packet based on the forwarding information; and

in response to receiving a second packet containing at least a prefix of the HSVLI and to identifying, via a second lookup in the local FIB that the HSVLI is a longest match for the prefix having a largest number of matched name components, forwarding the second packet based on the forwarding information.