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Clarent 400Gw – Cisco5300 PRI connection

Viewing 8 posts - 1 through 8 (of 8 total)
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  • #26502

    My Clarent 400GW acts as a switch and I send call from Clarent to Cisco using PRI connection. My Cisco then send the call to other carrier thru VoIP. Everything seems fine but after the call is connected 15s, it drops. debug isdn q931 gives me the call release reason “Recovery on timer expiry”. Do anyone has any idea to solve it?

    *Feb 19 09:43:41.038: ISDN Se0:23 Q931: RX CALL_PROC pd = 8 callref = 0x8300

    Channel ID i = 0xA98397
    Exclusive, Channel 23
    *Feb 19 09:43:41.434: gtd_dump_gtd_from_raw_msg: GTD message is empty
    *Feb 19 09:43:42.402: ISDN Se0:23 Q931: TX -> PROGRESS pd = 8 callref = 0x8300
    Progress Ind i = 0x8188 – In-band info or appropriate now available
    *Feb 19 09:43:43.050: ISDN Se0:23 Q931: TX -> ALERTING pd = 8 callref = 0x8300
    *Feb 19 09:43:44.730: ISDN Se0:23 Q931: TX -> CONNECT pd = 8 callref = 0x8300
    *Feb 19 09:43:44.742: ISDN Se0:23 Q931: RX DISCONNECT pd = 8 callref = 0x8300
    Cause i = 0x80E6 – Recovery on timer expiry
    *Feb 19 09:43:59.786: ISDN Se0:23 Q931: RX RELEASE_COMP pd = 8 callref = 0x8300

    ben roberts

    The gateway releasing the call is expecting to see a connect ack message. I’m not sure from teh trace which is teh Clarent and which is the cisco. There is a registry key in the clarent gateway that can be added to always send connect ACK, but I cant quite remember it. Accorsing to Q931 specs connect ACK is not manadatory unless you are in master mode, try swapping over the master clocking role.
    Hope this helps,


    Well, i am not sure but can i give some idea, i think it cannot talk between different platforms. So, you’ll need some sort of a ‘middleman’ device. In doing so, both platforms can communicate with each other.


    your issue is that you need to change your

    Call processing T303 interval
    Call processing T308 interval
    Call processing T310 interval
    Call processing T313 interval

    timers to 60 seconds.

    these are your ISDN timers that control how long they wait for proceeding and progress messages.

    for some strange reason Clarent set them at 10 and 15 seconds on default. Simply change the setting and you will be good to go. Let us know if you need more help, glad to help.


    forgot to mention there are two sets of timers in the regsitry some at the top (the ones i mentioned and some at the bottom of the clarent server reg foder)

    steve ccie-dial

    you need to run the isdn debugs on the remote side to see what that there disconnect reason it as we are recieving the disconnect.


    Hi Denis,

    I’ve got a problem that identical to yours. I have a Cisco AS5800, registered to a VocalTec VoIP network under VocalTec Gatekeeper. From AS5800, I made call to a VocalTec GW (VGW480), the call was connected but dropped after 15 seconds. The SS7 trace in PSTN side show me that the release cause is “Recovery on timer expiry”
    . Please tell me what did you do with your Clarent and Cisco GW. I think it could help me to solve my problems


    hi Khoa,

    im sorry that this problem is remainded open… but i think this should be related to timer settings…

Viewing 8 posts - 1 through 8 (of 8 total)
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