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OCS2007 Network Planning. - Network Traffic flow. RRS feed

  • Question

  • Hi All,

     

    We are investigating aggressively rolling out OCS 2007 to provide IM and Video Conferencing. Some of our WAN sites have very expensive bandwidth and we need to get clarity on how OCS behaves on a WAN network and over the Internet.

     

    From my research I understand that each Video Call requires a minimum of 300Kbps of Bandwidth to sustain conversation and that more is better. Audio requires 45kbps. Network links also have to have 150ms or less of latency on them.

     

    What we need to understand is what paths do these traffic flows take?

     

    If there is a Video call between 2 parties does the 300Kbps of traffic go from PC1 direct to PC2 (after the call is initiated)  or is it PC1 to Server1 to PC2 ?

     

    Also in a conferencing configuration is it hub and spoke as PCs talking to server. Does each conference member who uses Voice and Video require a 345kbps 150ms latency connection to the OCS server? Is this the same requirements for external parties connecting over the internet.?

     

    Any help with gaining clarity on this matter would be greatly appreciated.

     

     

    Lachlan Botticchio

    IT Infrastructure Architect

    MCSE CCNA

     

     

     

     

    Wednesday, July 4, 2007 7:49 AM

Answers

  • 2 person meetings/calls are peer to peer, if you have more than 2 the server takes over. Thus on a 2 person call it would just be between the 2 clients. When you have more then 2, all traffic would be handled by the server.

    I will try to get more exact info on the bandwidth needed by each client.

    Friday, July 6, 2007 9:18 PM

All replies

  • 2 person meetings/calls are peer to peer, if you have more than 2 the server takes over. Thus on a 2 person call it would just be between the 2 clients. When you have more then 2, all traffic would be handled by the server.

    I will try to get more exact info on the bandwidth needed by each client.

    Friday, July 6, 2007 9:18 PM
  •  

    Any luck with this info - would be helpful to see how server deals with traffic and bandwidth.
    Monday, August 6, 2007 12:44 AM
  • Has anyone discovered more on this topic or perhaps encountered some relevant data using the latest QoS and BPA Tools that MS has released.  It would be good to see some production metrics on OCS deployments that utilize A/V to get a better understanding of the overall impact on the network and the quality of calls users are experiencing.

     

    Friday, November 16, 2007 8:15 PM
  • My understanding and findings on traffic flow is as follows _ for voice\video stream

    On a private network

    If a call involves two MOC users the call is client to client.

    If a call involves two parties,  MOC and a PSTN user, the call is MOC user to the mediation server.

    If a call involves more then two parties then all calls go from the clients to the OCS server (in a hub and spoke as you suggested)

     

    Over the Internet

    If the call involves two external MOC clients then typically the call is client to client though this is not guaranteed (as it depends on the NAT device at each client end). If client to client direct connection is not possible the call is MOC <=> AV Edge <=> MOC.

    If the call involves an external and an internal MOC client the call is External Client => AV Edge <= Internal Client

    If the call involves an external MOC client and the PSTN the call is External Client => AV Edge <= Mediation Server

    If the call involces an external MOC client to more then one other user the call is External Client => AV Edge <= OCS Server. (All other end points also make a connection to the OCS server) 

     

    SIP traffic for call setup\control\tear down is always client to OCS server. (For internet clients MOC => Access Edge => OCS). However the bandwidth required is very low.

     

    Tuesday, January 8, 2008 9:09 AM
  •  

    What is the situation if you have distributes servers?  If I have two locations, each one with a Standard OCS server and 4 people in each location having a video conference.

    Does the video streams go server to server (so there is one stream across the WAN) or 4 video streams from the user talking and the four in the remote location?

    Tuesday, August 26, 2008 8:19 PM
  • This is the document you want to read to know more about bandwidth and OCS (and quality)

     

    Microsoft Quality of Experience

    http://www.microsoft.com/downloads/details.aspx?familyid=05625AF1-3444-4E67-9557-3FD5AF9AE8D1&displaylang=en

     

    Tuesday, August 26, 2008 10:07 PM
  • Nice Document but it really does not answer the question whether 2 OCS servers, each at a location connected by a WAN link, reduce the number of video streams between multiple A/V conferences at each location.  Can anyone answer that?

     

    Wednesday, August 27, 2008 1:51 PM
  • Are you talking about users in various locations participating in the same A/V Conference?

    Then there is only one server doing the A/V mixing and that is the server where the organizer or initiator is located

    The 2 servers will not work together to mix the A/V Stream

    Offcourse the codec between server and client can very in bandwidth over the WAN so there you optimization

     

     

     

    Wednesday, August 27, 2008 4:44 PM
  • yes.  Let's say 4 users at location A having a A/V conference with 4 users at location B.  If there were only 1 OCS server at Location A, then I believe after the call is setup, the user at location A would be streaming 4 video streams across the WAN to the 4 users at location B.  Correct?

     

    I was hoping that if there were a OCS server at location B, then a single video stream would go from server A to Server B and then to the 4 users in location B.

    Does it work this way?

     

    Wednesday, August 27, 2008 7:02 PM
  • That would be 4 streams to location B

     

     

    Thursday, August 28, 2008 9:19 AM
  • There would be four streams flowing from the A/V conferencing server in location A to the four clients in location B. Each client is only (sending or receiving) one stream.

     

    To be clear, this is a bit of a simplification, since audio and video are actually separate streams, and this doesn't include the possibility of panoramic video from the Microsoft Roundtable device...

     

    But in terms of understanding the media flow in a given call or conference, each client only ever talks to one other endpoint at a time, either another client, a Mediation server, or an MCU (conferencing server).

    Monday, October 27, 2008 11:19 PM