Cisco Systems RFC 2543 and RFC 3261 appendix SIP Header Fields, SIP Response, Meaning, Supported?

Appendix A SIP Compliance

RFC 2543 and RFC 3261

Table A-3 SIP Responses (continued)

SIP Response

Meaning

Supported?

Cisco SPS Action

5xx Response—Server Failure Responses
500	Server internal error	Server or gateway encountered an	Yes	Generates and forwards this
		unexpected error that prevents it from		response.
		processing the request.
501	Not implemented	Server or gateway does not support the
		functions required to complete the
		request.
502	Bad gateway	Server or gateway received an invalid	See Cisco SPS	Forwards this response.
		response from a downstream server.	action
503	Service unavailable	Server or gateway is unable to process	Yes	Generates and forwards this
		the request due to an overload or		response.
		maintenance problem.
504	Gateway timeout	Server or gateway did not receive a	See Cisco SPS	Forwards this response.
		timely response from another server	action
		(such as a location server).
505	Version not supported	Server or gateway does not support the	Yes
		version of the SIP protocol used in the
		request.
6xx Response—Global Responses

600	Busy everywhere	Called party was contacted but is busy	See Cisco SPS
		and cannot take the call at this time.	action
603	Decline	Called party was contacted but cannot
		or does not want to participate in the
		call.
604	Does not exist anywhere	Server has authoritative information
		that the called party does not exist in the
		network.
606	Not acceptable	Called party was contacted, but some
		aspect of the session description was
		unacceptable.

Forwards this response.

SIP Header Fields

Note All SIP header fields that concern the Cisco SPS are correctly handled and parsed except for the Hide and Encryption header fields. Header fields that do not directly affect the Cisco SPS or that are unknown to it are passed unaltered in the SIP request.

Cisco SIP Proxy Server Administrator Guide

A-6