CCM, gateway and FW

Discussion in 'Cisco' started by JS, Oct 26, 2005.

  1. JS

    JS Guest

    I have a CCM and a H323-gateway at the office. The gateway has a E1 ISDN out
    to the PSTN. I have now tried to install a Firewall between the
    CCM/IP-phones and the Gateway.

    Outgoing calls to pstn works fine with the FW in between, but incoming calls
    does not. The call reaches the phone, but gets immidiately disconnected, and
    I can see 1 missed call on the phone.The caller gets the ringback tone, but
    the phone does not ring.

    The FW only has one rule at the moment, permit any any. I can not see any
    traffic from/to my phone being dropped on the FW. Routing works fine between

    Where should I start looking for the problem?
    JS, Oct 26, 2005
    1. Advertisements

  2. Most likely it's NAT problem. Could you put a sniffer to the LAN between GW
    and FW and see what happens after call is made? Do you have proper settings
    on your GW? If you installed the firewall between GW and CCM, you must be
    doing some NAT. If traffic goes from the CCM to GW, it does automatic NAT
    translation as regular outbound traffic. But inbound traffic probably should
    have static NAT translation.

, Oct 30, 2005
    1. Advertisements

Ask a Question

Want to reply to this thread or ask your own question?

You'll need to choose a username for the site, which only take a couple of moments (here). After that, you can post your question and our members will help you out.