I was recently doing some testing with an ITSP (SIP PSTN provider), and was having trouble getting Jabber to connect.
CUCM would pass back "488 Not Acceptable Media" for any call Jabber tried to place to the SIP trunk that ties our CUCM to our CUBE.
The root cause is video. We configure a Region for our SIP Trunk Device Pool that disallows video by setting allocated bandwidth to "None". But, on our SIP trunk, we did not have the "retry video call as audio" checkbox set. It seems that Jabber ALWAYS sends the video bits as part of the SIP INVITE it sends with an outbond call, regardless of the setting you have configured in Options > Calls.
Media Description, name and address (m): video 28726 RTP/AVP 126 97
This is not a bad thing, as it's more convenient to use Early Offer for this type of media than it is to have to do a reINVITE-by-default when the clients want to use video. But, you need to configure CUCM defensively when dealing with Jabber calls to SIP providers outside your. The working checklist I now have is:
Configure a special Region for your ITSP trunks, and set the video bandwidth to None for all inter-region connections.
Set the "retry video calls as audio" flag on the SIP Trunk
Most ITSP's require early offer, so set the Early Offer support for voice and video calls (insert MTP as needed)
Having MTP's shouldn't be needed as long as your end-to-end codec support matches Jabber's, and your media doesn't need to be transcoded.
The gotcha, is that if you actually have a 3rd-party SIP provider that supports video, you are not going to be able to use the same CUBE for both video and non-video calling. This is because CUCM won't allow you to create more than one SIP trunk to the same gateway device. Realistically, Cisco expects you to use the Expressway servers for 3rd-party video calling, so I won't go into that end of it any deeper.
I'm testing all this on CUCM 9.1, IOS 15.3 CUBE, and Jabber FCS 9.7, not sure if anything changes in later versions of CUCM/CUBE.
hi all, i have a requirement to house 2-3 sub-company under a parent company sharing one CUCM UC infra & E1 link. Is it possible to share split the 30channels in the E1 PSTN from telco? Eg 10 channels to be dedicated to each sub-company with...
Hi, I am deploying a Cisco 4331 Gateway connected to an Avaya Gateway. What I want to do is the following. PSTN ---> E1 R2 ---> Cisco 4331 ---> E1 R2 ---> Avaya Gateway. Do you know if having E1 R2 signaling at...
Dear Experts, We have UCCX 11.5 system. Currently we are doing call redirect to PSTN number after office hours.During this pandemic situation, managing calls by one person is beyond control. So we would like to create a script for adding multipl...
I have many users that are now working from home. Some of them do not have voice mail because their job duties don't require it. They were given Jabber for Windows to use as a softphone for home use. Several times a day, I get multiple n...
Do the 7800 and 8800 series phones honor the Maximum Number of Calls line setting?I have them set to Max Number of Calls = 2 and Busy Trigger =1.The Busy Trigger works as expected.But I am able to stack up at least 4 calls on the line with the Max Calls s...