We have the following setting:
SIP Provider --- SBC --- CUCM --- ExpresswayC/E --- Jabber
When I start a call on the Jabber, I do not hear ringback.
All Invites are sent with early offer.
We get a 183 w/SDP from the provider, properly forwarded by the SBC and the CUCM to the Expressway. Anyway, it never arrives at the Jabber Client.
After some research we found the following:
Bug CSCtx90434 - 183 not supported / VCS responds to 183 session progress message with "Unsupported Message"
Bug CSCul52293 - Edge calls are missing or have incorrect tones and announcements
And this in a community entry:
"Now the release note about "Early Media" specifically refers to the fact that Expressway will drop SIP messages of the type "183 Session Progress" - it will not propagate them to the end system, and it will not open up media channels to conduct the media. So if an called party replies with that message, the edge endpoint will never be told to "ring", and will get dead air until the call actually connects "
So we will suffer dead air instead of ringback until this is fixed in the Expressway SW.
I apologize i hadn't heard back on this for sometime I missed your request, but yes this must be what is happening, been swamped with other work so haven't had a chance to do a pcap capture yet. When i do i will confirm that it is rejecting the 183 messages. Thank you.
The new X8.5 software version for Expressway/VCS appliances has been made available for download on CCO as of yesterday (Dec 17th). The new version adds support for SIP Early Offer over MRA, as well as unsolicited NOTIFY pass-through (for features like MWI), among other neat features. Check Release Notes for more information.
i have upgraded the expressway E and C to the latest 8.5.1 version but i still have the same problem ( no ringback tone).
I have Expressways connected to cucm using a H323 gateway.
Thank you in advance