Inbound calls drop after 4 seconds RRS feed

  • Question

  • Hi,
    I have an issue where inbound calls from external phones to users snom phones will drop after 4 seconds. In this 4 seconds the calls are connecting and audio is going both ways. This only happens on 1 site with all of their phones so initially it indicated to me a network issue so we put one of the phones in the DMZ and tried again to the same problem. The calls on their site do work perfectly fine on MOC  and outbound calls to PSTN also work without an issue. The exact same phones with the exact same configuration works from my office without any problems at all. All the phones and MOC are going through the edge server which is where we have been running our debug logs.

    In the OCS Edge debug log the only things I can see that concern me are 2 messages of the following:

    Direction: incoming;source="external edge";destination="internal edge"
    Peer: 213.123.*.*:49353
    Message-Type: response
    Start-Line: SIP/2.0 487 Request Terminated


    Text: Message or one of its headers caused SIP transaction processing error
    Result-Code: 0xc3e93c09 PE_E_TRANSACTION_DOES_NOT_EXIST
    SIP-Start-Line: SIP/2.0 200 OK
    SIP-Call-ID: d570d628-f949-49f0-9c26-767190644657
    SIP-CSeq: 155 CANCEL

    A pcap trace on the Snom phone does also not show any problems as far as I can see so I am struggling to see where the issue is considering it is only for inbound calls from the PSTN gateway. All other calls work fine whether they are inbound or outbound.

    I can provide the full log if needed just it will take me a wile to strip out all of the server IP's etc. I am extremely grateful for any help anyone can offer as I have been trying different settings for about a week now to no luck!

    Best Regards.

    Tuesday, October 5, 2010 7:23 AM