Cisco Telepresence test failing due to SDP being rewritten

[sconley]

We ran http://test.callway.com on our network to test Cisco WebEx Telepresence and it fails due to the following:

Issue

Your firewall is altering SIP messages and interfering with the proper operation of WebEx Telepresence.

What does this mean?

Your calls may drop or not complete successfully, and you may not be able to use extended features.

What can I do?

Disable the SIP ALG funcationality (VoIP fixup) in your firewall settings.  Click here to see how.

Test details

SIP invites to Test Network

video call ...

FAILURE
SDP has been rewritten - firewall with SIP ALG in your network?

Does anyone know how to resolve this?

[sconley · Accepted solution]

Looks like the issue was due to NATing.  We resolved the issue and got it working correctly.

[djrodb]

Hi - Can you tell me what you done re NAT?

Thanks

Rod