SDP question

[brendan.oneill]

Hello,

Could somebody please explain how a AS5300 gateway(or any other endpoint for that matter) determines between an SDP offer and an answer.

RFC 3264 ( the offer/answer model) states "If an agent receives an offer after having sent one, but before receiving an answer to it, this is considered a "glare" condition."

What I am trying to understand is how the gateway would detect the recieved SDP as being an offer rather than an answer to its own offer?

[ssoberlik]

This URL should help you:

http://www.cisco.com/en/US/products/sw/iosswrel/ps1834/products_feature_guide09186a008007fe37.html

[brendan.oneill]

Hi,

Thanks for your reply.

That document describes the MGCP feature but does not go in to how the SDP is negotiated.

The reason I ask is that we have a call scenario where an SDP offer is being recieved by the gateway after it has sent an offer. It appears to be seeing this offer as an answer to its own previous offer. ( rather than a glare condition). I am trying to understand if this is normal behaviour.

[agopala]

we go by call ID. If the SDP ok you get from the other gateway has the same call ID, you know it is an answer.

MGCP does not force SDP to be sent out in a VERB. you can just get SDP in an OK. we do accept that