Polycom Version 1.4.x 17 - Manual (Page 142)

Administrator Guide - SoundPoint ® IP / SoundStation ® IP Session Initiation Protocol (SIP)
134 Copyright © 2004 Polycom, Inc.
5.1.4 Response Support
In the following table, a “Yes” in the Supported column means the header is parsed.
The phone may not actually generate the response.
5.1.4.1 1xx Responses - Provisional
5.1.4.2 2xx Responses - Success
Supported Yes
Timestamp No
To Yes
Unsupported No
User-Agent Yes
Via Yes
Warning No
WWW-Authenticate Yes
Response Supported Notes
100 Trying Yes
180 Ringing Yes
181 Call Is Being Forwarded No
182 Queued No
183 Session Progress Yes
Response Supported Notes
200 OK Yes
202 Accepted Yes In REFER transfer.
Header Supported Notes