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  • Push mail generates high data usage

    Since this weekend I'm using a HTC TyTN with Windows Mobile 6. While I was already using a Exchange 2003 SP2 server, I prefered using Push Mail. In the Exchange System Manager I set Push Mail enabled but did not yet define the security policy. My TyTN is also configured to use push mail. As far as I know it should work.

    Problem is the high use of data. As far as I know, the GPRS connection will be kept alive with small amounts of data. If a change in the mailbox occurs (eg new mail), the EXchange server gives the TyTN the order to synchronize. Untill that signal, nothing will be synchronized. The heartbeat which keeps the connection alive is (default) set at 480 seconds, but is automatically adjusted by an algoritm.

    Question 1: Is this correct; do I understand Push Mail?

    I don't receive new mails directly (time =< 60 seconds) on my TyTN, but after about 8 minutes (there are those 480seconds again). Each 8 minutes, the PDA initiates a full synchronisation, unless the fact that I configured it only to sync 'When new items arrive.' Problem is the high amount of data generated, more than 140kb in less then one hour. Due to the fact that I have a 5mb subscription I should have a average usage of 170kb each day. It seems that -something- is going wrong.

    Question 2: What is going wrong (or is this the way it sould work)?

    If anyone needs log-files to help me, I have them available, so please ask . I can't find anything special in it.
    Last edited by SierdW; 25th April 2007, 11:52.

  • #2
    Re: Push mail generates high data usage

    Your understanding of how it works is pretty much on the spot.

    That sounds like the connection isn't being maintained and a full sync is taking place every eight minutes instead of on demand.
    The usual culprit is a firewall somewhere blocking the traffic or disconnecting the session.

    Are you using SSL?

    Simon.
    --
    Simon Butler
    Exchange MVP

    Blog: http://blog.sembee.co.uk/
    More Exchange Content: http://exchange.sembee.info/
    Exchange Resources List: http://exbpa.com/
    In the UK? Hire me: http://www.sembee.co.uk/

    Sembee is a registered trademark, used here with permission.

    Comment


    • #3
      Re: Push mail generates high data usage

      Thanks for your response Simon,

      I am using SSL, with a self created certificated, added to the root of the PDA. I do have a firewall in my router (Alcatel Speedtouch 510i), which blocks all ports execpt the ones I allow (80, 443 etc).

      I just hard resetted the device, because I read that the first connection should be made over GPRS. This didn't solve the problem.

      Is it possible to determine with log-files if and why the connection is lost (logs on PDA/server), please specify which ones you need and I'll post what's in it.

      Thanks in advance,

      Sierd

      Comment


      • #4
        Re: Push mail generates high data usage

        The logs on the server will not show anything, at most that the connection was dropped. They will not show any reason why.

        The only logs that might say something is on the firewall, but that depends on how in depth the firewall logs can go.

        Simon.
        --
        Simon Butler
        Exchange MVP

        Blog: http://blog.sembee.co.uk/
        More Exchange Content: http://exchange.sembee.info/
        Exchange Resources List: http://exbpa.com/
        In the UK? Hire me: http://www.sembee.co.uk/

        Sembee is a registered trademark, used here with permission.

        Comment


        • #5
          Re: Push mail generates high data usage

          Hmmm, well I can't access logs on my router as far as I know. I do have a txt file with the exchange log. I hope you can read something from that. Link

          /edit It is possible for me to have a long session in Outlook Web Access, that's not automatically disconnected. I don't know if this means anything...

          /edit2 Would lowering the heartbeat solve the problem?
          Last edited by SierdW; 25th April 2007, 20:44. Reason: ^^

          Comment


          • #6
            Re: Push mail generates high data usage

            AS I suspected, the logs do not show anything.

            OWA doesn't actually keep an open session. Technically HTTP shouldn't maintain a long connection, it is designed to connect, request, get, drop. The browser caches the credential information and when you next connect the same information is passed across, or the cookie checked or whatever.

            This is the only KB article I am aware of about the heartbeat.
            http://support.microsoft.com/?kbid=905013

            However as it identifies you should be getting something in the event log of the server.

            Simon.
            --
            Simon Butler
            Exchange MVP

            Blog: http://blog.sembee.co.uk/
            More Exchange Content: http://exchange.sembee.info/
            Exchange Resources List: http://exbpa.com/
            In the UK? Hire me: http://www.sembee.co.uk/

            Sembee is a registered trademark, used here with permission.

            Comment


            • #7
              Re: Push mail generates high data usage

              Well, nothing is logged in the Event-Log of the server. I hoped the problem would be 'easy' to solve, but if the firewall in my router is the problem, I'm affraid I can't solve it at all.

              I will keep looking and trying, thanks for your help so far.

              Sierd

              Comment


              • #8
                Re: Push mail generates high data usage

                Can you not take the firewall out of the equation for a few minutes while you conduct your testing?

                Michael
                Michael Armstrong
                www.m80arm.co.uk
                MCITP: EA, MCTS, MCSE 2003, MCSA 2003: Messaging, CCA, VCP 3.5, 4, 5, VCAP5-DCD, VCAP5-DCA, ITIL, MCP, PGP Certified Technician

                ** Remember to give credit where credit is due and leave reputation points sigpic where appropriate **

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                • #9
                  Re: Push mail generates high data usage

                  As far as I know there is no firewall in the router, but I think there -is- something in the router which times out the connection. I just monitorred the traffic with TCPview on the server and I saw the following:

                  I connect the phone through GPRS with the server @ 11:46. The phone is connected to https. TCPview shows Connection Established the whole time, but after 8 minutes, drops, and connects again on the clientport + 1.

                  Code:
                  time   Local Address            Remote address
                  11:46  server.domain.nl:https   phone_ip:1030
                  11:54  server.domain.nl:https   phone_ip:1031
                  12:02  server.domain.nl:https   phone_ip:1032
                  To me it seems that the connection is dropped, maybe by the timeout in the router.

                  I will take a look at the possibilities to change the connection time-out.

                  If anyone thinks there is an other problem, I would like to hear it

                  /edit
                  I did find information about timeouts of my router, and adjusted them to 1 hour. Following settings are now applied, but had no effect...

                  Timeout ICMP idle : 01h00m
                  Timeout UDP idle : 01h00m
                  Timeout TCP idle : 01h00m
                  Timeout TCP negotiation idle : 01h00m
                  Timeout Other idle : 01h00m
                  IKE outside port number : Floated

                  /edit2
                  It seems that messages do arrive on the PDA directly when they arrive at the server just a few seconds after the first synchronisation. There is something ending the connection after a few seconds I think, but what?

                  /edit3
                  I have tried direct push with my PDA on someone else's server and it worked perfectly. The PDA can't be the problem...
                  Last edited by SierdW; 26th April 2007, 18:12.

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                  • #10
                    Re: Push mail generates high data usage

                    Anybody with ideas? Just flashed my router to a new firmware, but that doesn't seem to help...

                    Comment


                    • #11
                      Re: Push mail generates high data usage

                      Originally posted by SierdW
                      I do have a firewall in my router (Alcatel Speedtouch 510i), which blocks all ports execpt the ones I allow (80, 443 etc).
                      Originally posted by SierdW
                      As far as I know there is no firewall in the router....
                      So, which one is it? Firewall or no firewall? The 510i does have a firewall so has it been enable or not. If it has, then Michael has made a good suggestion to see if the firewall can be eliminated as a cause.
                      1 1 was a racehorse.
                      2 2 was 1 2.
                      1 1 1 1 race 1 day,
                      2 2 1 1 2

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                      • #12
                        Re: Push mail generates high data usage

                        Yesterday I started experimenting again on this issue. I discovered a virtual PDA of Microsoft which I installed. This to make sure nothing was wrong with my Exchange installation.

                        But...

                        Push did not work on the virtual PDA, which points (in my opinion) to a problem with the server and not the internet connection/ speedtouch router. In order to make sure there was nothing wrong with the virtual directories i resetted the directories with this article.: http://support.microsoft.com/kb/883380. Didn't help me at all. Somehow the connection is not maintained and disconnected.

                        Anyone who has an idea on what the problem can be?

                        Comment


                        • #13
                          Re: Push mail generates high data usage

                          You have to start looking at whether anything else is interfering with the traffic - firewall, AV software etc. Something is causing the connection to be dropped.

                          Simon.
                          --
                          Simon Butler
                          Exchange MVP

                          Blog: http://blog.sembee.co.uk/
                          More Exchange Content: http://exchange.sembee.info/
                          Exchange Resources List: http://exbpa.com/
                          In the UK? Hire me: http://www.sembee.co.uk/

                          Sembee is a registered trademark, used here with permission.

                          Comment


                          • #14
                            Re: Push mail generates high data usage

                            Thanks for your reply Sembee. I have stopped the AV instance, as firewall I'm using the basic firewall/ NAT of RRAS. The firewall of my speedtouch router is excluded while on the local-WLAN it is not working too.

                            I'm running different webserver instances in IIS with different hostheaders site1.domain.eu, site2.domain.eu and also webmail.domain.eu in which the Exchange VDirs are placed. Can this cause the problem?

                            I have attached the CtrlLog.txt from my PDA to this message, maybe anyone can find something in that or if anyone needs another logfile, please say it.
                            Attached Files

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                            • #15
                              Re: Push mail generates high data usage

                              Host headers can cause connection problems, but I wouldn't expect to see something like this caused by host headers.

                              Simon.
                              --
                              Simon Butler
                              Exchange MVP

                              Blog: http://blog.sembee.co.uk/
                              More Exchange Content: http://exchange.sembee.info/
                              Exchange Resources List: http://exbpa.com/
                              In the UK? Hire me: http://www.sembee.co.uk/

                              Sembee is a registered trademark, used here with permission.

                              Comment

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