RCC to MOC call: Video Escalation Fails RRS feed

  • Question

  • A client is seeing the following scenario:


    1. User 1 and User 2 both have PBX integration enabled (Nortel CS1K).

    2. User 1 places RCC call to User 2 (i.e. User 1 Preferred Calling Device is Phone).

    3. User 2 picks up call on phoneset.

    4. User 2 attempts to escalate to video call by clicking on the webcam icon on the top left of his conversation window.

    5. Escalation fails.  A message says "An error has occurred during the call (ID: 52024).


    I looked at SIP traces for both User 1 and User 2.  When User 2 attempts to escalate the call, it sends the following SDP with its INVITE:



    o=- 0 0 IN IP4


    c=IN IP4


    t=0 0

    m=video 5350 RTP/AVP 121 34


    a=candidate:zvZRP8zh3r57Adw499WXnTLmLeWHo0Cqbh9JecPScCo 1 hDG6z34LCyHOscj8poBFYA UDP 0.830 5350

    a=candidate:zvZRP8zh3r57Adw499WXnTLmLeWHo0Cqbh9JecPScCo 2 hDG6z34LCyHOscj8poBFYA UDP 0.830 5351

    a=candidate:ypBBST1pyEInltYadBrsU/DeVFgO4iKMouiC0LwFPsE 1 X6exltKVfAdaSJdr/bOynw UDP 0.840 5350

    a=candidate:ypBBST1pyEInltYadBrsU/DeVFgO4iKMouiC0LwFPsE 2 X6exltKVfAdaSJdr/bOynw UDP 0.840 5351

    a=cryptoscale:1 client AES_CM_128_HMAC_SHA1_80 inline:G82LeInPHFQKqlMmZzK6FV1LHWOC++gA7vipQ28s|2^31|1:1

    a=crypto:2 AES_CM_128_HMAC_SHA1_80 inline:JpScKbx29ja2il0pkvEjhqBsK04YkUxoJsPbxqj5|2^31|1:1


    a=rtpmap:121 x-rtvc1/90000

    a=rtpmap:34 H263/90000



    User 1 rejects this INVITE with 488 Not Acceptable Here message.  The MS-proxy-diagnostics field of the message is:


    Ms-client-diagnostics: 52024; reason="Video only sessions are not supported"


    While its true that the SDP only includes a media line for video, this was not a problem when I reproduced the same scenario in my own lab.  When an OC in the middle of an audio call, it can handle the SDP with only a video media line and successfully establishes video.


    I suspect there is either some parameter that needs to be changed or some patch required to make this scenario work correctly and allow the user to respond appropriately.  Does anybody have any ideas?

    Friday, May 23, 2008 2:46 PM


All replies