SIP Functions, SIP Methods | Cisco Systems RFC 2543 and RFC 3261

Appendix A SIP Compliance

RFC 2543 and RFC 3261

SIP Functions

Table A-1

SIP Functions

Function

Proxy server

Redirect server

Registrar server

Supported?

Yes (transaction stateful, parallel forking, and recursive)

Yes

Cisco SPS supports five of the six methods used by SIP. It handles unknown methods such as

NEWMETHOD in the same manner as known methods such as OPTIONS and REFER.

Table A-2	SIP Methods

Method		Supported?	Cisco SPS Action

ACK		Yes	Forwards ACK requests.1
BYE		Yes	Forwards BYE requests.

CANCEL		Yes	Forwards CANCEL requests.2
INFO		Yes	Forwards INFO requests.

INVITE		Yes	Forwards INVITE requests.

NOTIFY		Yes	Forwards NOTIFY requests.

OPTIONS		Yes	Responds to OPTIONS requests.

REFER		Yes	Forwards REFER requests.

REGISTER		Yes	Supports both user and device registration.

SUBSCRIBE		Yes	Forwards SUBSCRIBE requests.

UPDATE		Yes	Forwards UPDATE requests.

1.The SPS can generate a local ACK for a non-200 OK final response to an INVITE request.

2.The SPS can generate a local CANCEL for a pending branch when it receives a 200 OK or 6xx response from the branch.

Cisco SPS supports the following SIP responses:

•1xx Response—Information Responses

•2xx Response—Successful Responses

•3xx Response—Redirection Responses

•4xx Response—Request Failure Responses

Cisco SIP Proxy Server Administrator Guide

A-2