OCS 2007 bandwidth/performance issues please help RRS feed

  • Question



    All we use OCS 2007 for is instant messaging and the presence information for about 140 people. The server sits in our data center and connects 14 remote locations thru T-1 lines. In an hour time it will output 200MB of data...for IM.  Every now and then the OCS server will saturate the lines and kill connections for other programs we use.  I gave this server the highest QoS group and it is in that group by itself b/c communicator would only work about 25% of the time if not.  Even with that high QoS it still only works about 90% of the time.  It will often fail to send messages, not display presence info, and even sign out and in.


    Any tips or advice?

    Wednesday, November 26, 2008 8:58 PM

All replies

  • Any number of things could be causing this.  Is that WAN or LAN traffic that you are measuring?  What is the bandwidth utilization of your T1 lines overall?  It sounds to me like packets are getting dropped on the network.  How large are people's contact lists?  The average user has about 5 presence changes an hour.  For simplicity's sake let's assume each presence change causes 1KB of data to go to the server (a quick check showed a presence update at 616 bytes, adding responses it would come to about 1KB on the wire).  With 140 users that's 700KB/hour.  Now, add to that each subscriber (contact) that is updated when my presence changes.  If I have 20 people on my list that's 21 updates (one from me and 20 to my contacts) * 5 presence changes per hour * 140 people = 14.7MB per hour..obviously a far cry from 200MB. To account for the rest of the traffic with IM only all your users would need to be sending about 25 IMs per minute on top of the presence traffic.


    I've never benchmarked the traffic between OCS and SQL, but presumably those are on the same LAN (or perhaps the same machine if you're running Standard Edition) so that shouldn't be a factor unless your 200MB figure includes LAN traffic, which would encompass AD and other regular Windows/network traffic.  Have you disabled A/V and web conferencing to ensure that people aren't using those?

    Wednesday, November 26, 2008 10:02 PM
  • How are you actually measuring this?

    Only port 5061?

    Or all traffic to and from OCS Server?

    Thursday, November 27, 2008 12:44 AM

    All traffic to an from OCS Server.  But when I drill down its all port 5060 traffic.  I will try disabling the A/V and web conference.  Do I want to stop the services or deactivate?
    Friday, November 28, 2008 1:58 PM
  • Just stop them for initial testing as deactivation is permanent and you'd have to reinstall the components or manually reactivate using command line parameters.


    Friday, November 28, 2008 2:01 PM
  • Disabling A/V and Web Conference will not help with port 5060 traffic (other ports are used for them)

    Actually it's kind of strange that you have that many traffic on port 5060 it is used for SIP traffic and that are only small messages unless you have too many users and all have very big buddy lists and IM all the time


    Did you manually change to unsecured traffic?

    OCS normally uses the secure port 5061




    Monday, December 1, 2008 9:42 PM

    I don't recall changing any ports, the program we use to analyze bandwidth is saying port 5060. 

    I tried disabling those services and messages will still error out, but "maybe" not as often.  We do have 140 users and each users has the 139 users on there contact list.  Is that the cause, to many users on the contact list?

    Tuesday, December 2, 2008 3:42 PM
  • That's exactly why I included that info - I've seen small businesses populate everyone on their contact list before and had a suspicion that might be the case here as well.  That is definitely adding to your bandwidth usage.  Remember that OCS automatically includes an address book so that your users can simply type in the name of another person in the search bar to start a conversation with them.  There's no need to include the entire company on everyone's contact list.

    Tuesday, December 2, 2008 3:55 PM
  • Lets try to do the maths


    200MB/Hour = 3.33MB/Minute = 0.055 MB/second = 55 KBytes / Second

    If we assume that one sip message is about 1K (allthow I think it will be a lot smaller, still need to do some investigation on this) then then 55 sip messages per second are exchanged

    That may be very high but with everyone having everyone on the buddy list it might just be correct

    Remeber that one presence state change is submitted to all subscribed clients (buddies in the list)

    Inactivity triggers a state change every 5 minutes and at noon that might have a big impact!


    Not even calculating any IM traffic


    And yes you should rethink your buddy list design if you want to lower the bandwidth requirements


    Tuesday, December 2, 2008 5:29 PM

    Ok, well I have permission to restructure the Contact list.  My problem is I use the AWESOME OCSCM tool at www.ocscm.com.  But its limited in how I can assign groups.  Now I want to give everyone 4 groups with about 5 people in each instead of all the groups we have before.  Are there any tools out there that can help?  Using the scripts is not really an option b/c it will not delete the previous groups I already have created.  And the scripts are a horrible way of managing contacts.


    Tuesday, December 2, 2008 8:10 PM
  • I did some testing on the size of the SIP messages when changing a status.

    Its hard to tell because most have different sizes, I saw a lot of 0.5K content length-messages and others ranging from 0 to 5K content-length but I only have 50 contacts and most of them are not online at this time so not receiving messages


    So I would conclude that having all users online in your contact list and have 140 contacts that would indeed generate many SIP messages and may wel be the reason why you see so many traffic and 1K might be a good calculating average for the size of the message


    Wednesday, December 3, 2008 12:10 AM
  • Another problem with keeping large contact lists is that Communicator Mobile users will see additional battery drain when signed in due to the increased communications to update presence information for many users.  That also greatly extends sign-in time for all clients, but it is clearly most noticeable on CoMo as well.


    Prepopulating the Contact List with large amounts of contacts is really against the intended design as the OCS Address Book is meant to handle that functionality.


    Wednesday, December 3, 2008 1:54 PM