Automatic NAT not working on SX20

[Dean.r.holmes]

I am working with a group that has SX20's behind 2900's using IOS firewall (but we have opened up the firewall to traffic) all registered to a central CUCM.  When these endpoints dial out to an independent H.323 endpoint we are getting one-way audio and video.  The independent endpoint is actually receiving the internal IP address for the SX20, not the external IP address.  When we force the SX20's to Manual NAT it works, but Auto NAT does not. 

Any thoughts here?  When you set the SX20 to Auto where does the proper NAT address reside?

[Oleksandr Yurchenko]

Hi Dean

Do your SX20 has a public IP or its internal IP is natted to public IP to communicate over internet ?

Show please internal IP and H323NAT_IP your SX20  and network diagram.

br Oleksandr

[Dharmesh Nandoria]

Hi

Please see below detail for NAT config.

H323 NAT Mode

The firewall traversal technology creates a secure path through the firewall barrier, and enables

proper exchange of audio/video data when connected to an external video conferencing

system (when the IP traffic goes through a NAT router). NOTE: NAT does not work in

conjunction with gatekeepers.

Requires user role:ADMIN

Value space:

Auto:The system will determine if the H323 NAT Address or the real IP address should be

used in signaling. This makes it possible to place calls to endpoints on the LAN as well as

endpoints on the WAN. If the H323 NAT Address is wrong or not set, the real IP address will

be used.

Off:The system will signal the real IP address.

On:The system will signal the configured H323 NAT Address instead of its real IP address

in Q.931 and H.245. The NAT Server Address will be shown in the startup-menu as: "My IP

Address: 10.0.2.1". If the H323 NAT Address is wrong or not set, H.323 calls cannot be set

There was a bug when NAT is configured still it was sowing internal IP adress to far end , This is fix in TC 6.x

CSCtz66999

H323 NAT sends non NAT IP address in Q931 display field causes far end

HTH

Kind regards,

Dharmmesh