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New Member

ATA 186 to CallManager over PIX

I have an ATA 186 ( and Call Manager 3.1.(2c). The ATA box works fine on the local LAN, but doesn't work outside PIX.

The following is my PIX config. What am I missing? Do I need other TCP ports opened? I did open any any, but it dodn't seem to fix the problem.

Also, I did see a transient connection in CM error log, which tells me that I am not completing the registration process.

Thank you,


fixup protocol skinny 2000

static (inside,outside) netmask 0 0

conduit permit icmp any any

conduit permit tcp host eq 2000 any

  • Other Collaboration Voice and Video Subjects
New Member

Re: ATA 186 to CallManager over PIX

According to a troubleshooting document I found it says "If you are using a firewall, make sure it is a Cisco PIX firewall, version 5 or later versions". Here is the link if you would like to read it.


Re: ATA 186 to CallManager over PIX

try no fixup protocol skinny 2000

also what do you mean by "doesn't work"? isn't it able to register withing the callmanager?can you place a call froman analog phone connected but there is no voice passed?

New Member

Re: ATA 186 to CallManager over PIX

Well, let me clarify.

I am able to register the phone since the last post. I fixed it by editing the phone .cnf file that contains the private IP address of the call manager. This seems to be a very poor solution, but it works.

My problem now is that I think the RTP stream is "broken". Basically, it seems that PIX doesn't change the private IP address of the remote phone (going over NAT), which means that there is only one way conversation. When I speak to headset attached to ATA the other side doesn't hear anything, but it works the other way around.

Any ideas? Has anyone done this before? Am I approaching the problem correctly?


P.S.: I posted something that might resemble a diagram in "ATA remote location design recommendation" thread.