TRACEROUTE USING ADDRESS REQUEST MESSAGES

• US 20080151764A1
• Filed: 12/21/2006
• Published: 06/26/2008
• Est. Priority Date: 12/21/2006
• Status: Active Grant

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Wing, Daniel G., Oran, David R., Andreasen, Flemming Stig
• Granted Patent: US 7,738,383 B2
• Time in Patent Office: Days
• US Class Current: 370/248
• CPC Class Codes: H04L 41/12 Discovery or management of network topologies
• CPC Class Codes: H04L 41/344 Out-of-band transfers
• CPC Class Codes: H04L 45/20 Hop count for routing purposes, e.g. TTL
• CPC Class Codes: H04L 61/2575 using address mapping retrieval, e.g. simple traversal of user datagram protocol through session traversal utilities for NAT [STUN]
• CPC Class Codes: H04L 61/2578 without involvement of the NAT server

Abstract

In one embodiment, an endpoint sends messages containing Simple Traversal of User Datagram Protocol (UDP) Through Network Address Translators (NATs) (STUN) requests to traceroute a path to the remote endpoint. The traceroute may be completed through security devices such as NATs and firewalls. Receipt of a STUN response from the remote endpoint signals that one of the traceroute packets reached the remote endpoint whereas the other traceroute packets have elicited error responses from intermediary, on-path routers, allowing these routers to be identified.

Claims

1. An apparatus, comprising:

one or more processors; and

a memory coupled to the one or more processors comprising instructions executable by the processors, the processors operable when executing the instructions to;

send a plurality of messages to a remote endpoint, each of the messages including a different lifetime value;

receive back a plurality of error responses identifying the presence of one or more routers located between an originating endpoint of the messages and the remote endpoint; and

receive back a non-error response message indicating completion of a traceroute to the remote endpoint.

2. The apparatus of claim 1 wherein the messages include address requests and the non-error response message includes an address of an intermediary network address translation device that is located remotely with respect to both endpoints.

3. The apparatus of claim 1 wherein at least one of the messages is configured to elicit the non-error response message from a Simple Traversal of User Datagram Protocol (UDP) Through Network Address Translators (NATs) (STUN) server located on the remote endpoint.

4. The apparatus of claim 1 wherein the processors are further operable to insert padding data into the messages for length manipulation.

5. The apparatus of claim 4 wherein all of the messages include different amounts of padding data.

6. The apparatus of claim 1 wherein the processors are further operable to:

send audio or video data to a Real Time Protocol (RTP) port on the remote endpoint;

wherein the plurality of messages are addressed to the same RTP port on the remote endpoint.

7. A method comprising:

establishing a session with a remote endpoint, the session associated with a first network path for transferring media to the remote endpoint and a second network path that is separate from the first network path, the second network path for transferring out of band control information associated with the media to the remote endpoint;

sending first traceroute communications over the first network path;

sending second traceroute communications over the second network path; and

receiving back error responses and non-error responses, the non-error responses corresponding to the first and second traceroute communications and generated by the remote endpoint.

8. The method of claim 7 wherein the first traceroute communications are addressed to a different valid port on the remote endpoint than the second traceroute communications.

9. The method of claim 7 wherein the traceroute communications include address request messages.

10. The method of claim 9 wherein at least one of the received non-error responses includes a payload identifying an Internet Protocol (IP) address for an intermediary on-path security device that provides network address translation.

11. The method of claim 7 further comprising including different amounts of padding data in the first and second traceroute communications.

12. The method of claim 11 wherein the padding data is one or more Simple Traversal of User Datagram Protocol (UDP) Through Network Address Translators (NATs) (STUN) attributes for increasing packet length.

13. The method of claim 7 wherein the first traceroute communications are addressed to an IP address and port that corresponds to a same IP address and port used for sending media.

14. An apparatus, comprising:

means for sending a plurality of address request messages having different lifetime values to a valid port on a remote endpoint;

means for receiving back one or more lifetime exceeded error messages, each of the lifetime exceeded messages indicating the presence of a router located between the remote endpoint and a local endpoint; and

means for receiving back a response message identifying traceroute completion.

15. The apparatus of claim 14 wherein the address request messages include Simple Traversal of User Datagram Protocol (UDP) Through Network Address Translators (NATs) (STUN) requests.

16. The apparatus of claim 14 further comprising means for inserting padding data into the address request messages to manipulate lengths of the address request messages.

17. The apparatus of claim 16 wherein the padding data is inserted into STUN payloads of the address request messages.

18. The apparatus of claim 14 further comprising:

means for sending audio or video data to a port on the remote endpoint; and

means for addressing the address request messages to the same port on the remote endpoint.

19. The apparatus of claim 14 further comprising:

means for tracerouting a Real-Time Protocol (RTP) path to the remote endpoint; and

means for tracerouting a Real-Time Control Protocol (RTCP) path to the remote endpoint;

wherein the RTP path and the RTCP path extend through different groups of routers.

20. The apparatus of claim 14 further comprising means for correlating each received lifetime exceeded error message to one of the address request messages by observing length fields included in the received lifetime exceeded error message.