Determination of an endpoint association from a transport address

• US 20050169169A1
• Filed: 01/30/2004
• Published: 08/04/2005
• Est. Priority Date: 01/30/2004
• Status: Abandoned Application

• Current Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Original Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Inventors: Gadde, Srinivas
• Application Number:
  US10/769,193
• Publication Number:
  US 20050169169A1
• Time in Patent Office: Days
• US Class Current: 370/229
• CPC Class Codes: H04L 45/745 Address table lookup; Address filtering
• CPC Class Codes: H04L 49/3009 Header conversion, routing tables or routing tags

Abstract

A received datagram is associated with the connection endpoint using a transport address index and an endpoint association array which includes a list of active transport addresses for each active endpoint association. At least some of the active endpoint lists include more than one transport address and each entry in the transport address index includes (or is linked to) one or more pointers to the specific transport addresses in the endpoint association array lists that are associated with that entry.

Claims

1. A method for determining an endpoint association between a transport address pair in a received datagram and an endpoint for the received datagram, at least some of the endpoints involving more than one transport address pair, the method comprising:

setting up an endpoint association array including for each active endpoint in the array a list of all the transport addresses involved with that endpoint;

setting up a transport address index for active transport address pairs including, for each separately indexed unit of transport addresses, individual pointers to all the potentially matching transport addresses in the endpoint array; and

using the transport address pair of the received datagram and the transport address index to locate an active endpoint association in the endpoint array that is associated with a matching transport address pair.

2. The method of claim 1 wherein the endpoints are local endpoints.

3. The method of claim 1 wherein the transport addresses are each in the form of a transmit address pair.

4. The method of claim 3 wherein at least some of the received datagrams are SCTP datagrams being received over the Internet, at least some of the transport address pairs include source and destination IP addresses and source and destination port numbers, and at least some of the endpoints are defined by SCTP associations.

5. The method of claim 3 wherein at least some of the received datagrams are TCP datagrams being received over the Internet, at least some of the transport address pairs include source and destination IP addresses and source and destination port numbers, and at least some of the endpoints are defined by TCP connections.

6. The method of claim 1 further comprising when setting up a new endpoint association:

inserting a new transport address list into the endpoint association array; and

inserting one or more new transport address pointers into all corresponding units of the transport address index.

7. The method of claim 1 further comprising when tearing down an old connection involving an identified transport address pair associated with an active endpoint association:

using the transport address index to locate the transport address list for that active endpoint association;

using the located transport address list to locate all other transport addresses involved with that same active endpoint association;

removing the pointers to the identified transport address pair and to any other transport addresses involved with that active endpoint association from the transport address index; and

then

removing the active endpoint and its associated transport address list from the endpoint association array.

8. The method of claim 1 wherein each said transport address is a transport address pair including a transmit node address, a receive node address, a transmit port address, and a receive port address.

9. The method of claim 1 wherein the transport address index includes a hash table, each separately indexed unit includes all the active transport addresses that are mapped to a single entry in the hash table, and at least one entry of the hash table has an associated collision list including more than one potentially matching transport address that is so mapped.

10. The method of claim 9 wherein the hash table is a two stage hash table, the second stage functions as respective collision lists for the first stage, and at least some entries in the first stage do not have any associated second stage collision list entries.

11. The method of claim 10 wherein the second stage is a single shared table.

12. The method of claim 10 wherein the second stage includes a separate table for each entry in the first stage having more than one potentially matching transport address.

13. The method of claim 1 further comprising the steps:

establishing a cache of recently encountered transport addresses; and

using the transport address index and the endpoint array to locate a matching endpoint only when the transport address of the incoming datagram is not in the cache.

14. The method of claim 13 wherein the cache includes at least some invalid transport addresses not linked to any active endpoint association.

15. The method of claim 13 wherein the cache includes at least some valid transport addresses linked to one or more active endpoint associations.

16. Machine-readable media containing a stored program for determining an association between a transport address pair in a received datagram and an endpoint for the received datagram, at least some of the endpoints including more than one such transport address pair, the stored program comprising:

a procedure for setting up an endpoint array including for each active endpoint in the array a list of all the transport addresses involved with that endpoint;

a procedure for setting up a transport address index for active transport address pairs including for each separately indexed unit of transport addresses individual pointers to all the potentially matching transport addresses in the endpoint array; and

a procedure for using the transport address pair of the received datagram and the transport address index to locate an active endpoint in the endpoint array that includes a matching transport address pair.

17. The media of claim 16 wherein the stored program further comprises a procedure for inserting a new transport address list into the endpoint array and for inserting one or more new connection transport address pointers into all corresponding units of the transport address index.

18. The media of claim 16 wherein the stored program further comprises

a procedure for using the transport address index to locate a transport address list for a specified endpoint and for using the located transport address list to locate all other transport addresses involved with that same active endpoint;

and

a procedure for removing the pointers to the identified transport address pair and to any other transport addresses involved with that active endpoint from the transport address index and for removing the active endpoint and its associated transport address list from the endpoint array.

19. The media of claim 16 wherein at least some of the received datagrams are SCTP datagrams being received over the Internet, at least some of the transport node addresses are IP addresses, and at least some of the endpoints are SCTP endpoints.

20. The media of claim 16 wherein the transport address index includes a hash table, each separately indexed unit includes all the active transport addresses that are mapped to a single entry in the hash table, and at least one entry of the hash table has an associated collision list including more than one potentially matching transport address that is so mapped.

21. The media of claim 20 wherein the hash table is a two stage hash table, the second stage functions as respective collision lists for the first stage, and at least some entries in the first stage do not have any associated second stage collision list entries.

22. The media of claim 16 wherein the stored program further comprises:

a procedure for establishing a cache of recently encountered transmission addresses and for using the transport address index and the endpoint array to locate a matching endpoint only when the transport address of the incoming datagram is not in the cache.

23. A communication node capable of determining an association between a transport address pair in a received datagram and an endpoint for the received datagram, at least some of the endpoints including more than one such transport address pair, the communication node comprising:

an endpoint association array including for each active endpoint association in the array a list of all the transport addresses involved with that endpoint association;

a transport address index for active transport address pairs including for each separately indexed unit of transport addresses individual pointers to all the potentially matching transport addresses in the endpoint association array; and

an automated process for using the transport address pair of the received datagram and the transport address index to locate an active endpoint association in the endpoint association array that includes a matching transport address pair.

24. The node of claim 23 wherein the automated process further comprises means for inserting a new transport address list into the endpoint association array and for inserting one or more new connection transport address pointers into all corresponding units of the transport address index.

25. The node of claim 23 wherein the automated process comprises:

a procedure for using the transport address index to locate a transport address list for a specified endpoint association and for using the located transport address list to locate all other transport addresses involved with that same active endpoint association; and

a procedure for removing the pointers to the identified transport address pair and to any other transport addresses involved with that active endpoint association from the transport address index and for removing the active endpoint association and its associated transport address list from the endpoint association array.

26. The node of claim 23 wherein at least some of the received datagrams are SCTP datagrams being received over the Internet, at least some of the transport node addresses are IP addresses, and at least some of the endpoints are SCTP endpoints.

27. The node of claim 23 wherein the transport address index includes a hash table, each separately indexed unit includes all the active transport addresses that are mapped to a single entry in the hash table, and at least one entry of the hash table has an associated collision list including more than one potentially matching transport address that is so mapped.

28. The node of claim 23 wherein the hash table is a two stage hash table, the second stage functions as respective collision lists for the first stage, and at least some entries in the first stage do not have any associated second stage collision list entries.

29. The node of claim 23 wherein the automated process further comprises:

a procedure for establishing a cache of recently encountered transmission addresses and for using the transport address index and the endpoint array to locate a matching endpoint only when the transport address of the incoming datagram is not in the cache.