APPLICATION-LAYER TRAFFIC OPTIMIZATION SERVICE SPANNING MULTIPLE NETWORKS

• US 20110296053A1
• Filed: 08/23/2010
• Published: 12/01/2011
• Est. Priority Date: 05/28/2010
• Status: Active Grant

• Current Assignee: Juniper Networks Incorporated
• Original Assignee: Juniper Networks Incorporated
• Inventors: Bakshi, Mayuresh, Penno, Reinaldo, Medved, Jan, Raghunath, Satish
• Granted Patent: US 8,688,775 B2
• Time in Patent Office: Days
• US Class Current: 709/241
• CPC Class Codes: H04L 47/70 Admission control; Resource allocation
• CPC Class Codes: H04L 67/1001 for accessing one among a plurality of replicated servers
• CPC Class Codes: H04L 67/101 based on network conditions
• CPC Class Codes: H04L 67/104 Peer-to-peer [P2P] networks
• CPC Class Codes: H04L 67/289 Intermediate processing functionally located close to the data consumer application, e.g. in same machine, in same home or in same sub-network

Abstract

Using the ALTO Service, networking applications can request through the ALTO protocol information about the underlying network topology from the ISP or Content Provider. The ALTO Service provides information such as preferences of network resources with the goal of modifying network resource consumption patterns while maintaining or improving application performance. This document describes, in one example, an ALTO server that intersects network and cost maps for a first network with network and cost maps for a second network to generate a master cost map that includes one or more master cost entries that each represent a cost to traverse a network from an endpoint in the first network to an endpoint in the second network. Using the master cost map, a redirector may select a preferred node in the first network with which to service a content request received from a host in the second network.

Claims

1. A method comprising:

generating, with a first Application-Layer Traffic Optimization (ALTO) server that includes a first ALTO client for a second ALTO server, a first ALTO network map that includes PID entries to describe each of a first set of one or more PIDs, wherein each of the first PIDs is associated with a subset of one or more endpoints of a first network;

generating, with the first ALTO server, a first ALTO cost map that comprises, for each combination of the first PIDs, a cost entry that includes a cost value to specify a cost to traverse a network path through the first network that connects the respective combination of the first PIDs;

receiving, with the first ALTO client of the first ALTO server, a second ALTO network map that includes PID entries to describe each of a second set of one or more PIDs, wherein each of the second PIDs is associated with a subset of one or more endpoints of a second network;

receiving, with the first ALTO client, a second ALTO cost map that comprises, for each combination of the second PIDs, a cost entry that includes a cost value to specify a cost to traverse a network path through the second network that connects the respective combination of the second PIDs;

generating a master cost map comprising one or more master cost entries that each include a PID selected from the first PIDs and a PID selected from the second PIDs and that each include a cost value that represents a cost to traverse a network path from the PID selected from the first PIDs and the PID selected from the second PIDs; and

outputting the master cost map from the first ALTO server to a second ALTO client.

2. The method of claim 1,

wherein the first network comprises a first border router associated with a PID entry of the first ALTO network map,

wherein the second network comprises a second border router associated with a PID entry of the second ALTO network map and connected to the first border router via a transit link,

wherein generating the master cost map comprises:

selecting a first selected PID from the first PIDs, wherein the first selected PID is not associated with the first border router;

selecting a second selected PID from the second PIDs, wherein the second selected PID is not associated with the second border router;

creating a first master cost entry that includes the first selected PID and second selected PID.

3. The method of claim 2, further comprising:

summing a cost entry value in the first ALTO cost map for the combination of the first selected PID and the PID for the first border router with a cost entry value in the second ALTO cost map for the combination of the second selected PID and the PID for the second border router to produce a total cost; and

setting the cost value for the first master cost entry to the total cost.

4. The method of claim 2, further comprising:

summing a cost entry value in the first ALTO cost map for the combination of the first selected PID and the PID for the first border router with a cost entry value in the second ALTO cost map for the combination of the second selected PID and the PID for the second border router and with a cost for the transit link that connects the first border router to the second border router to produce a total cost; and

setting the cost value for the first master cost entry to the total cost.

5. The method of claim 2,

wherein the PID entry of the first ALTO network map associated with the first border router includes a PID-type field identifying the PID entry of the first ALTO network map associated with the first border router as comprising a border router,

wherein the PID entry of the second ALTO network map associated with the second border router includes a PID-type field identifying the PID entry of the second ALTO network map associated with the second border router as comprising a border router.

6. The method of claim 2, further comprising:

generating a first border router cost matrix for the first network that specifies a cost of reaching the first border router from other first PIDs in the first ALTO network map; and

generating a second border router cost matrix for the second network that specifies a cost of reaching the second border router from other second PIDs of the second ALTO network map.

7. The method of claim 1, wherein the first network and the second network operate in separate administrative domains.

8. The method of claim 1, wherein the first network is a content delivery network.

9. The method of claim 8,

wherein at least one of the first PIDs represents one or more content delivery nodes,

wherein at least one of the second PIDs represents one or more consumers of content served by the content delivery nodes, and

wherein the master cost map specifies costs to traverse network paths from each of the first PIDs that represent content delivery nodes to each of the second PIDs that represent consumers.

10. A method comprising:

receiving, with a redirector device, a first Application-Layer Traffic Optimization (ALTO) network map that includes PID entries to describe each of a first set of one or more PIDs, wherein each of the first PIDs is associated with a subset of one or more endpoints of a first network;

receiving, with the redirector device, a second ALTO network map that includes PID entries to describe each of a second set of one or more PIDs, wherein each of the second PIDs is associated with a subset of one or more endpoints of a second network;

receiving, with the redirector device, a master cost map comprising one or more master cost entries that each include a PID selected from the first PIDs and a PID selected from the second PIDs and that each include a cost value that represents a cost to traverse a network path from the PID selected from the first PIDs and the PID selected from the second PIDs;

receiving, with the redirector device, a content request from a host endpoint;

querying the second ALTO network map to determine a PID associated with the host endpoint in the second PIDs;

querying the master cost map to determine a lowest-cost PID in the first PIDs for the PID associated with the host endpoint; and

selecting an endpoint associated with the lowest-code PID in the first ALTO network map to service the content request from the host endpoint.

11. The method of claim 10, further comprising returning a network address of the selected endpoint to the host endpoint in response to the content request.

12. The method of claim 11, wherein returning the network address causes the host endpoint to issue a second content request to the selected endpoint.

13. The method of claim 10, wherein querying the second ALTO network map comprises mapping a network address of the host endpoint to an associated PID in the second PIDs.

14. A first application-layer traffic optimization (ALTO) server comprising:

a network map module to generate a first ALTO network map that includes PID entries to describe each of a first set of one or more PIDs, wherein each of the first PIDs is associated with a subset of one or more endpoints of a first network;

a cost map module to generate a first ALTO cost map that comprises, for each combination of the first PIDs, a cost entry that includes a cost value to specify a cost to traverse a network path through the first network that connects the respective combination of the first PIDs;

a first ALTO client to receive a second ALTO network map that includes PID entries to describe each of a second set of one or more PIDs, wherein each of the second PIDs is associated with a subset of one or more endpoints of a second network,

wherein the first ALTO client receives a second ALTO cost map that comprises, for each combination of the second PIDs, a cost entry that includes a cost value to specify a cost to traverse a network path through the second network that connects the respective combination of the second PIDs, and

wherein the network map module and cost map module generate a master cost map comprising one or more master cost entries that each include a PID selected from the first PIDs and a PID selected from the second PIDs and that each include a cost value that represents a cost to traverse a network path from the PID selected from the first PIDs and the PID selected from the second PIDs; and

a client interface to output the master cost map from the first ALTO server to a second ALTO client.

15. The first ALTO server of claim 14,

wherein the first network comprises a first border router associated with a PID entry of the first ALTO network map,

wherein the second network comprises a second border router associated with a PID entry of the second ALTO network map and connected to the first border router via a transit link, and

wherein, to generate the master cost map, the network map module selects a first selected PID from the first PIDs, wherein the first selected PID is not associated with the first border router,

wherein, to generate the master cost map, the network map module selects a second selected PID from the second PIDs, wherein the second selected PID is not associated with the second border router, and

wherein, to generate the master cost map, the cost map module creates a first master cost entry that includes the first selected PID and second selected PID.

16. The first ALTO server of claim 15, wherein the cost map module:

sums a cost entry value in the first ALTO cost map for the combination of the first selected PID and the PID for the first border router with a cost entry value in the second ALTO cost map for the combination of the second selected PID and the PID for the second border router to produce a total cost; and

sets the cost value for the first master cost entry to the total cost.

17. The first ALTO server of claim 15, wherein the cost map module:

sums a cost entry value in the first ALTO cost map for the combination of the first selected PID and the PID for the first border router with a cost entry value in the second ALTO cost map for the combination of the second selected PID and the PID for the second border router and with a cost for the transit link that connects the first border router to the second border router to produce a total cost; and

sets the cost value for the first master cost entry to the total cost.

18. The first ALTO server of claim 15,

wherein the PID entry of the first ALTO network map associated with the first border router includes a PID-type field identifying the PID entry of the first ALTO network map as comprising a border router, and

wherein the PID entry of the second ALTO network map associated with the second border router includes a PID-type field identifying the PID entry of the second ALTO network map as comprising a border router.

19. The first ALTO server of claim 15, wherein the cost map module:

generates a first border router cost matrix for the first network that specifies a cost of reaching the first border router from other first PIDs in the first ALTO network map; and

generates a second border router cost matrix for the second network that specifies a cost of reaching the second border router from other second PIDs of the second ALTO network map.

20. The first ALTO server of claim 14, wherein the first network and the second network operate in separate administrative domains.

21. The first ALTO server of claim 14, wherein the first network is a content delivery network.

22. The first ALTO server of claim 21,

wherein at least one of the first PIDs represents one or more content delivery nodes,

wherein at least one of the second PIDs represents one or more consumers of content served by the content delivery nodes, and

wherein the network map module and cost map module generate the master cost map to specify costs to traverse network paths from each of the first PIDs that represent content delivery nodes to each of the second PIDs that represent consumers.

23. A redirector device comprising:

a location database;

an Application-Layer Traffic Optimization (ALTO) client to receive a first ALTO network map that includes PID entries to describe each of a first set of one or more PIDs, wherein each of the first PIDs is associated with a subset of one or more endpoints of a first network,

wherein the ALTO client receives a second ALTO network map that includes PID entries to describe each of a second set of one or more PIDs, wherein each of the second PIDs is associated with a subset of one or more endpoints of a second network, and

wherein the ALTO client receives a master cost map comprising one or more master cost entries that each include a PID selected from the first PIDs and a PID selected from the second PIDs and that each include a cost value that represents a cost to traverse a network path from the PID selected from the first PIDs and the PID selected from the second PIDs,

wherein the ALTO client stores the first ALTO network map, the second ALTO network map, and the master cost map to the location database; and

a lookup module to receive a content request from a host endpoint,

wherein the lookup module queries the second ALTO network map to determine a PID associated with the host endpoint in the second PIDs,

wherein the lookup module queries the master cost map to determine a lowest-cost PID in the first PIDs for the PID associated with the host endpoint, and

wherein the lookup module selects an endpoint associated with the lowest-code PID in the first ALTO network map to service the content request from the host endpoint.

24. The redirector device of claim 23, wherein the lookup module returns a network address of the selected endpoint to the host endpoint in response to the content request.

25. The redirector device of claim 24, wherein the network address causes the host endpoint to issue a second content request to the selected endpoint.

26. The redirector device of claim 23, wherein the lookup module queries the second ALTO network map by mapping a network address of the host endpoint to an associated PID in the second PIDs.

27. A computer-readable storage medium comprising instructions to cause a programmable processor to:

generate, with a first Application-Layer Traffic Optimization (ALTO) server that includes a first ALTO client for a second ALTO server, a first ALTO network map that includes PID entries to describe each of a first set of one or more PIDs, wherein each of the first PIDs is associated with a subset of one or more endpoints of a first network;

generate, with the first ALTO server, a first ALTO cost map that comprises, for each combination of the first PIDs, a cost entry that includes a cost value to specify a cost to traverse a network path through the first network that connects the respective combination of the first PIDs;

receive, with the first ALTO client of the first ALTO server, a second ALTO network map that includes PID entries to describe each of a second set of one or more PIDs, wherein each of the second PIDs is associated with a subset of one or more endpoints of a second network;

receive, with the first ALTO client, a second ALTO cost map that comprises, for each combination of the second PIDs, a cost entry that includes a cost value to specify a cost to traverse a network path through the second network that connects the respective combination of the second PIDs;

generate a master cost map comprising one or more master cost entries that each include a PID selected from the first PIDs and a PID selected from the second PIDs and that each include a cost value that represents a cost to traverse a network path from the PID selected from the first PIDs and the PID selected from the second PIDs; and

output the master cost map from the first ALTO server to a second ALTO client.