[SIPForum-discussion] Changing Codecs on the Fly

[Kevin P. Fleming]

Skibinski, Jeffrey wrote:
> Is an endpoint allowed to change the Codec it is using (e.g., from G.711
> to G.729) in the middle of a dialog without renegotiating with the other
> endpoint?  What is the proper method of changing codecs in the middle of
> a dialog if necessary?

An endpoint can send media in any format that the other endpoint offered
to receive for that session during SDP negotiation. There is no need to
indicate the switch in the SIP signaling.

Switching to a format that is not in the other endpoint's list requires
negotiation via re-INVITE.

-- 
Kevin P. Fleming
Digium, Inc. | Director of Software Technologies
445 Jan Davis Drive NW - Huntsville, AL 35806 - USA
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