Polycom Version 1.4.x 17 Hold Implementation, Reliability of Provisional Responses, Transfer

Administrator Guide - SoundPoint® IP / SoundStation® IPSession Initiation Protocol (SIP)

Response	Supported	Notes
606 Not Acceptable	No

5.1.5 Hold Implementation

The phone supports both currently accepted means of signaling hold. The first method, no longer recommended due in part to the RTCP problems associated with it, is to set the “c” destination addresses for the media streams in the SDP to zero, for example, c=0.0.0.0. The second, and preferred, method is to signal the media direc- tions with the “a” SDP media attributes sendonly, recvonly, inactive or sendrecv. The hold signaling method used by the phone is configurable (for more information, see

4.6.2.1.3SIP <SIP/> on page 115) but both methods are supported when signaled by the remote endpoint.

5.1.6Reliability of Provisional Responses

The phone fully supports RFC 3262 - Reliability of Provisional Responses.

5.1.7 Transfer

The phone supports transfer using the REFER method specified in draft-ietf-sip-cc- transfer-05 and RFC 3515.

5.1.8 Third Party Call Control

The phone supports the delayed media negotiations (INVITE without SDP) associated with third party call control applications.

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