ATA 186 & Call Manager & H.323 Gateway

ATA 186 & Call Manager & H.323 Gateway

Post by <al » Wed, 10 Apr 2002 02:15:17

Quote:> I am trying to figure out a way to tackle this problem & would really
> hearing some suggestions at this point...

> I have a Cisco Call Manager (3.1(2c)).  I'm using ATA 186's to connect to
> the Call Manager (as skinny clients).  I have a 2600 series router set up
> as an H.323 gateway - the router is connected to the PSTN via a PRI.  I
> have the 2600 defined as a gateway on the Call Manager.  I have a route
> pattern defined on the Call Manager to send traffic to the gateway.

> All of that is okay.

> The problem is that I'm having to use the ATA's from behind a firewall
> running NAT.  When the ATA registers with the Call Manager, it registers
> with it's private address (  When I place a call from the
> ATA to a PSTN number, the call goes out perfectly - but because there's no
> route back to the ATA, I hear nothing - I've tested by calling my home
> number from the ATA & my home number rings.

> How do any of you get around this problem??  My long-term goal is to ditch
> H.232 & use MGCP on the 2600 (as I understand it, that will fix the
> problem), but that won't be possible for a few more weeks & I need to try
> to get something working in the meantime.

> The firewall in question is just a Linux box running IPCHAINS & IPMASQ.
> I take the Call Manager out of the picture & use SIP to send calls from
> ATA directly to the 2600 router, they work fine.  I thought about setting
> up an H.323 proxy on my firewall (something like OpenH323), but I really
> don't even think that would help - since the ATA registers it's private
> address with the Call Manager...

> Any ideas?

> Thanks.

H.323 has IP Address information in the data portion of the packet. You will
need an application level proxy to rewrite that information.