Delay before call ringing RRS feed

  • Question

  • Sometimes it appears that a call takes longer to ring/signal.  The user making the call hears "blip-blip-blip...." and then finally a ring tone.  This is for both OC calls and for PSTN calls.  Logs suggest that it is taking this long to connect the call.  What's the delay?


    I can't isolate the scenario where this happens.  I once thought it was when I was using VM's, but it also happens on production hardware.


    Has anyone else seen this?




    Friday, January 11, 2008 9:35 PM

All replies

  • Hi Mark,

    Does this happen to users who are external to your corporate network & who are connecting through the Edge? Or does this happen to internal users as well?


    I've noticed that it sometimes takes a while for OCS to figure out which IP addresses to use with STUN when trying to establish a Voice/Video call for users coming through the Edge. If you run NetMon or Wireshark on your clients, you can see all the different attempts to get the call connected using various different methods: your IP address, your NAT'd IP address, the IP address of the remote party, that person's NAT'd IP address, the A/V server's IP etc. The client makes that blipping noise when it's sorting out the signalling. When it finds the right combination that works, then the call goes through. At least that's been my experience.





    Tuesday, January 15, 2008 8:17 PM
  • Hi Matt,


    Do you have an suggestions on how to eliminate the delay issue? 




    - Rob


    Friday, February 15, 2008 10:20 PM
  • Hi Rob,
    If you have your A/V edge server with a publicly routable IP address, I think that's about all you can do to eliminate the delay. Also, clients connecting through proxy servers tend to have more delay, so if you can route traffic around the proxy, you'll be in better shape.

    And as I mentioned above, run Wireshark on your client to look at the traffic and see what the client is doing - that's the best way to determine the source of the delay and then it may be easier to figure out what to do to eliminate the delay.

    Saturday, February 16, 2008 1:29 AM
  • I am experiencing this delay in our environment as well.  All the users log into a VPN in order to use the voice features for OCS.  Due to infrastucture restrictions, we are unable to get a public IP address for the edge.


    Originally the user's were experiencing 13 seconds delay.  We checked the mediation server and there was an access edge for voice specified when we do not have one available.  When we changed that setting to none, the delay dropped to 7 seconds.  We have been stuck at 7 seconds for the past month and am working with MS to resolve this issue. 


    Have you been able to get your delay reduced Mark?

    I'll keep you posted on any developments on my end.



    (Hi Rob!)

    Tuesday, March 4, 2008 6:56 PM
  • We have been able to get rid of the delay before the call rings.


    In the global settings we had set to use an A/V edge serverr for authentication. When a user would come into our environment using the Access Edge (only works for IM) the user could place a call and hear immediate ring back, but could not connect the call.  When the user came in through our company network to the data center the caller would get the delay.  

    Through our log files we discovered the client was not receiving the authorization from the A/V edge server.  To resolve we removed the A/V edge server from the global properties settings, where you specify the name of the edge server for authorization. 



    Thursday, April 17, 2008 1:56 PM