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  • Voice qaulity issues

    I've got a 100 user lawfirm which got a new shoretel VOIP system installed back in October. I am the contracted network engineer for this site. since day one of install random users experience voice qaulity issues with static noise, echo and clicking. This problem does not occur on internal calls and is intermitten and random. The shoretel VAR who sold the system is not helpful in trying to solve the problem. I have performed extensive testing with my Fluke nettool II VOIP tester and port monitoring on the switches. The switches are adtran Netvanta 1224st PWR running COS they are layer two. The only significant packet problems is happening between the switch and the shoregear 90 and 50, also see a lot of packet errors between the switch and the shoregear T1. As well as a shoregear 24a device throwing a lot of packet errors. I am currently running wireshark and mirroring the T1. Does anyone hve any feed back or experience with these switches operating with the shoretel equipment described?

  • #2
    Audio Quality

    We have Netvanta 1224st switches. Other than the firmware bug that causes phones to randomly lose power and reboot every so often (corrected in 10.10), they have been rock solid.

    The problems you describe sound like a bad PRI to me. You could have 1 channel out of 24 that is bad. You would only have problems on EXTERNAL calls that happened to get that single channel. If it was a channel in the middle somewhere (outgoing calls go out the bottom channels first, incoming come in the top) you may only hit that bad channel every blue moon (when call volume is high).

    I would think that if you had real network issues inside, the problems would be more consistent.

    when you say a lot of packet errors, what exactly are you seeing? I would have the phone company come out with a TBIRD test set and test the PRI. They can also pull error stats off the smartjack.

    You can use the trunk test tool to make calls on each individual channel and search for one that has quality issues as well.

    gary
    Last edited by eazeaz; 03-02-2009, 08:00 AM.

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    • #3
      Thanks Gary for the reply. here is the errors I see, in these attachments.
      Attached Files

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      • #4
        I started a trouble ticket with the provider of the T1. Is the trunk test tool a utility in the shoretel system?

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        • #5
          Adtran

          what firmware level are these on?

          can you post your QOS config on these as well

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          • #6
            Voice Quality

            Can you also look at your T1 switch and see if there are any errors shown on the PRI?
            Attached Files

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            • #7
              Gary these switches are capable of COS I included the config. The switches also have spanning tree protocol enabled and I got different opions on this being enabled. I am waiting for the phone engineer to arrive to get into the shoregear T1 gateway.
              Attached Files

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              • #8
                T1 Switch

                Dont be chicken.

                Get in the switch.

                What could possibly go wrong?

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                • #9
                  Is this installation in Manchester, USA or UK? Just checking as I maybe able to help if it is in the UK. Sorry, no experience with T1's though.

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                  • #10
                    manchester usa, I did test each channel via VBtrunk test they tested ok. Gary what do you think about the COS config or can I get a copy of the running config on your switches. I don't have the user credentials for the T1 switch I will try to get them today. When the phone tech was here last night we did go into the switch and I did not see any T1 errors. take a look at this app log from the shoretel server lots of entries with packet loss. I also have a wireshark report I ran.
                    Attached Files

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                    • #11
                      Network Issue

                      It absolutely looks like you have a network issue. Particulary ONLY with packets going in and out of the PRI T1 switch.

                      You are losing packets between a variety of sources and the pri switch.

                      I filtered your event log for event #119's (excessive packet loss). I then sorted by time. It sure looks like no packets are ever lost before 7 am and all the packet loss stops at 425pm.

                      This is probably too big a coincidence to ignore. Sounds like lawyer hours to me.

                      To not have a single event happen between 425 and 7am may just be strange luck I guess.... or that no phone calls are happening, so there is no packet loss to report.

                      It looks like either your QOS is not working, or you have a basic network issue going to the PRI switch (bad patch cable, port, auto negotiation on one end went to half duplex accidentally, etc).

                      I would try making some phones calls after hours and start up as much network traffic as you can. See if you can cause packet loss with an increase in traffic......

                      Is the T1 switch in the same office as all the other gear, or does it go over a WAN?

                      gary

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                      • #12
                        Spanning Tree should be disabled on any port that has ShoreTel equipment.

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                        • #13
                          Gary I think you nailed it!

                          I followed your thoughts and hard set the adtran ports which have the shoretel equipment on them to full duplex 100 mb. I have not seen any events thrown to the app log and my user issues have all but gone. Clearly time will tell if it is fixed. STP is disabled on all shoretel equipment but not on the ports to the phones. the T1 switch is local in the server room with a 3' patch cable to the adtran switch. The shoretel phone vendor tech did say that he sets the shoretel equipment not to auto negotiate and hard codes Full dup at 100mb.

                          thanks for your help everyone I will follow up with final results after some history.

                          Mike

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                          • #14
                            hard set

                            if you hard set the adtran port, you really want to have the equipment plugged into it hard set as well.

                            you dont want one side to negotiate while the other end is hard set.

                            Someone should go into the t1 pri switch and hard set it too.

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                            • #15
                              On your screenshots of the T1, 24A, & 90, the 'late collisions' are an indication that there is a duplex mismatch between you ethernet swtich and the shoregear switches. Also I am not sure you have the right statistics for the 90 because it shows PoE on.

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