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CUBE with UCCX, Re-Invites mid call during script causing dropped calls

Level 1
Level 1

Hello, I have an issue with a CUBE which is connecting our PBX to the PSTN via a sip trunk, specifically when the call is put through a UCCX script we are finding that at each stage of the call, from the Initial answering, placing on hold, resume from hold to play second hold message, placing back on hold after this message, there are re-invite messages being sent to the ITSP. They do not expect to see this and it is causing them us to drop the calls, they have commented that they beleive that this is due to the conversation being what they would expect to see between our PBX (CUCM 8.5) and the CUBE not between the Cube and the ITSP. I have noticed that the newer version of IOS has a feature to block re-invite messages mid call which would appear to be able to fix the issue however I cannot imagine that this would of been required as otherwise users with UCCX would of been experiencing major issues with SIP trunks over the last few years when I have supported customers and not known any such issue. My question is this, is there some mis configuration that is causing the CUBE to relay the various stages of the call to the ITSP when it should only be stopping at the CUBE itself and only passing on signalling when the call is being cleared to the ITSP?


Matt Smith.

3 Replies 3

Level 7
Level 7

Hi Matt,

I had a very similar issue recently.  We were hitting a bug in the CUBE and we had to enable MTP required on the SIP trunk from CUBE to CUCM to remove the re-invites to the CUBE from taking place which was causing UCCX dropped calls.  We initially had the SIP trunk set up to 'insert MTP when required' to avoid MTP usage, however we had to force MTP required for all calls to avoid a very similar scenario.  We ended up creating IOS Software MTP's to ensure it doesn't eat up CPU cycles on the CUCM IPVMS subscriber.



Gergely Szabo
VIP Alumni
VIP Alumni

Hi, yes, it is frustrating. Should be solved in CUBE 8.8.


Sent from Cisco Technical Support iPad App

With CUBE 8.8 (IOS 15.2.T) A re-invite will only be sent when the media changes, not when a call is put on hold..

This is an excerpt from Randy Wu (CIsco CUBE/SIP Trunk Expert)

. for the RE-INVITE during hold, there is a new feature coming up with CUBE 8.8 version (IOS 15.2.1T), in which it can be blocked and only will be passed through when the media changed.

    the example command will be like this:

     voice service voip  

        midcall-signaling block

        midcall-signaling passthru media-change

. for the REFER message, there is also new enhanced  feature coming up with CUBE 8.8 version (15.2.1T) as well, in which  will enables CUBE to handle REFER messages more efficiently, called REFER consumption, or REFER pass-through.

   the example command will be like this:

REFER Consumption

Based on “Refer-To” header, CUBE does outbound dial-peer match and sends out an INVITE message

voice service voip

   no supplementary-service sip refer

   supplementary-service media-renegotiate

REFER Pass-through

CUBE will pass across the Refer message “as-is” without any modification

voice service voip

  supplementary-service sip refer




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