PAP2-NA VOIP adapter does not work with ISA only with linksys

Posted on 2007-07-31
Last Modified: 2008-11-17
Hi All
I have a PAP2-NA linksys phone adapter..the thing is that it works normally with a linksys router but on ISA it just does not work. It used to work fine for a while on ISA then one day it stopped working upon investigating the matter I noticed that the return port being used was the port of the machine not the port mapped during the natting process.
I.e. ISA was receiving the packet with destination port 1710 instead of the port it assigned during the natting port. Of course ISA has port 1710 closed and will therefore block the packet.
It seems as if ISA is not natting correctly.
I need to get it working on ISA has anyone found a workaround for this..has it happened to anyone else ?
I did not change any of the settings of ISA.

Question by:http://
    LVL 2

    Expert Comment

    Yes, you're correct. You can't use VOIP systems through ISA easily.

    The trick is to use a SIP proxy or a stun server to force the incoming ports to the one you specify.

    Its easier to use IAX instead of SIP in this case.
    LVL 9

    Accepted Solution

    Under SIP tab enable "Insert Via rport" and it'll work
    LVL 19

    Author Comment

    Thank you michofreiha you are a strong man in VOIP...I did that and it worked
    LVL 51

    Expert Comment

    by:Keith Alabaster
    As a note - I have deleted the pointer question you had asked and refunded the points that were associated with it.

    Networking Zones Advisor

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