SIP Response Codes

SIP responses are the codes used by Session Initiation Protocol for communication. We have put together a list of all the SIP responses known.

1xx = Informational SIP Responses

100 Trying – Extended search is being performed so a forking proxy must send a 100 Trying response.
180 Ringing – The Destination User Agent has received the INVITE message and is alerting the user of call.
181 Call Is Being Forwarded – Optional, send by Server to indicate a call is being forwarded.
182 Queued – Destination was temporarily unavailable, the server has queued the call until the destination is available.
183 Session Progress – This response may be used to send extra information for a call which is still being set up.
199 Early Dialog Terminated – Send by the User Agent Server to indicate that an early dialogue has been terminated.

200 OK – Shows that the request was successful
202 accepted – Indicates that the request has been accepted for processing, mainly used for referrals.
204 No Notification – Indicates that the request was successful but no response will be received.

300 Multiple Choices – The address resolved to one of several options for the user or client to choose between.
301 Moved Permanently – The original Request URI is no longer valid, the new address is given in the Contact header.
302 Moved Temporarily – The client should try at the address in the Contact field.
305 Use Proxy – The Contact field details a proxy that must be used to access the requested destination.
380 Alternative Service – The call failed, but alternatives are detailed in the message body.