Unable to video/audio conference between internal and external parties RRS feed

  • Question

  • Video- and audio calls are working great using Communicator. That is, calls between 2 external users or 2 internal users have no problem.

    But calls between an internal and external user seem to encounter a problem.

    When I click the 'Call was disconnected' message in Communicator it always says on the external side:

    'The call was disconnected because Test Internal stopped receiving audio. Please try the call again.

    and on the internal side:

    'The call was disconnected because Communicator stopped receiving audio from Test External. Please try the call again.

    All validation tests on the FE and Edge machines complete without error. What could be the problem?
    Friday, December 12, 2008 1:55 PM

All replies

  • Is your A/V Edge interface using an IP address that is directly accessible (no NAT) from both the inside and outside of your network?
    Mike Stacy | Evangelyze Communications | http://www.evangelyze.net/cs/blogs/mike
    Monday, December 15, 2008 6:02 AM
  • Yes, that's affirmative.
    Monday, December 15, 2008 11:55 AM
  • This turned out to be a misconfiguration in one of our internal DNS servers. Works fine now.

    ---edit: problem is not solved, only looked that way because I moved the internal clients to a domain member.

    please see below for follow up
    • Marked as answer by ®win Wednesday, December 17, 2008 2:34 PM
    • Unmarked as answer by ®win Thursday, December 18, 2008 4:13 PM
    • Edited by ®win Thursday, December 18, 2008 4:49 PM
    Wednesday, December 17, 2008 2:34 PM
  • Gents, We have the same problems, could you pls explain what u did in yours internal DNS?

    We have the same problem what autor said, but i got solution, its not good solution but at least its work, so we start VPN service and now all external users connecting by vpn to internal network... so at least it work but its not good way , and video straem is so slow, I really dont understand why....
    external to external - video quality and audio - perfectly
    internal to Internal - video quality audio - perfectly
    external to internal - video quality so poor, audio perfectly

    on both side internet channel speed is ~ 1 Mb/s without any firewalls (we exclude it for make sure it will work better, but no...)

    so any other solutions?

    Wednesday, December 17, 2008 2:54 PM
  • Are you able to use IM between internal and external clients? Does videoconferencing work between two external clients?
    Thursday, December 18, 2008 12:29 PM
  • yea IM its working, A/V does not///

    do u have msn? could u add me? a_burlachenko@hotmail.com

    many thx
    Thursday, December 18, 2008 2:57 PM
  • It sounds like there is a problem with the connection between your edge and front end serve, did you check this? Maybe test the connection with a file transfer between edge and front end.

    Also try the validation tool on both edge and front end.

    ps I added you to my private msn, which I don't use much by the way.
    Thursday, December 18, 2008 3:06 PM
  • Using Wireshark I was able to find out this is happening because the internal and external clients are trying to connect to eachothers private ip address, instead of their external routable address.

    Of course their private addresses cannot connect to eachother because they are on a completely different LAN.

    This looks like the STUN protocol going wrong here. (explained on page 101 of the OCS_Planning_Guide.doc)

    I hope anyone can tell what might be going wrong here, are the explanation in the guide isn't all that good...
    Thursday, December 18, 2008 4:56 PM
  • Well this is a common issue.  Mainly around MRAS and candidate lists.  First turn on logging from your Communicator clients - internal and external.  Start a AV session.

    Assuming the internal client started the AV Call.  Lets look at the Outbound -> INVITE

    You will see something simillar to this...

    a=candidate:9LErjK/41TZiB10pfkbkGLwf9MfcYx5UGjFpcoVn3SM 1 hT5GTsxZQtC5EPbn6kZYsg UDP 0.830 9732
    a=candidate:9LErjK/41TZiB10pfkbkGLwf9MfcYx5UGjFpcoVn3SM 2 hT5GTsxZQtC5EPbn6kZYsg UDP 0.830 3514
    a=candidate:dhT8H52DotfI+CgHvP88MXTkIX7fHigr0CdLHlmVMdo 1 X5Mv5fzwvPxSwPay/YkUPg TCP 0.190 50404
    a=candidate:dhT8H52DotfI+CgHvP88MXTkIX7fHigr0CdLHlmVMdo 2 X5Mv5fzwvPxSwPay/YkUPg TCP 0.190 50404
    a=candidate:FONwi/X+jXHX0p8SklVRESeQzoglcoKGhcRqFCwf3P0 1 bDMkHk9tXJub/cKbuL/TRQ UDP 0.490 52046
    a=candidate:FONwi/X+jXHX0p8SklVRESeQzoglcoKGhcRqFCwf3P0 2 bDMkHk9tXJub/cKbuL/TRQ UDP 0.490 50542
    a=candidate:0qvo0dDJIzSOjzmgvwVfB2SNsx1M4c3raLFtIdjEptw 1 z3WiRuKxFOvX/VnubuhOYQ TCP 0.250 5288
    a=candidate:0qvo0dDJIzSOjzmgvwVfB2SNsx1M4c3raLFtIdjEptw 2 z3WiRuKxFOvX/VnubuhOYQ TCP 0.250 5288

    Here you can see internal IP's and a Public IP of the AV Edge.  The public IP is not a real AV Edge - just a IP to use for this purpose.

    Now if you only see the internal IP, then we know the internal client is having issues talking with the internal MRAS interface.  Next we can look at the external client, this time it will not be an invite packet but a OUT 200 OK if looking at the external client logs, if looking at the internal client Logs - it would be a IN 200 OK.  Either way do they have a internal and the Public IP of the AV Edge?

    Once this is answered we can move on to the next step.

    Monday, December 29, 2008 12:10 AM