Specifications

Appendix
397
Method
Supported
Notes
Refer-To
Yes
Referred-By
Yes
Remote-Party-ID
Yes
Replaces
Yes
Require
Yes
Route
Yes
RSeq
Yes
Session-Expires
Yes
Subscription-State
Yes
Supported
Yes
To
Yes
User-Agent
Yes
Via
Yes
SIP Responses
The following SIP responses are supported:
1xx Response—Information Responses
1xx Response
Supported
Notes
100 Trying
Yes
180 Ringing
Yes
181 Call Is Being Forwarded
Yes
183 Session Progress
Yes
2xx Response—Successful Responses
2xx Response
Supported
Notes
200 OK
Yes
202 Accepted
Yes
In REFER transfer.