Ok I have a very strange issue with my TMG right now. We are using the TMG to publish a SIP Server for inbound calls (from PSTN) over a trunk from our provider. Now this works fine 99,9% of the time, but there is a scenario that I have confirmed now happens
every time.
Setup is:
Internal LAN - has internal PBX and SIP clients on same network, all media is routed through our media gateway so no RTP or SIP is coming directly from the clients to the TMG.
External WAN - we have a trunk to our provider so we can make extarnal calls and also recieve calls from PSTN.
SIP/RTP published using wizard
Works fine 99% of the time.
The scenario when the problem occurs is as follows:
- Someone internally makes an outbound call.
- A SIP request is sent from our internal PBX to external vendor.
- TMG initiates a SIP session.
- Outbound call is established - all is fine.
- While above call is ongoing, someone tries to dial in.
- We recieve an inbound call (protocol SIP Server) from PSTN.
- TMG initiates connection (i.e. does not deny it).
- TMG *immediately* closes the inbound connection with the following error:
Closed Connection XXXXXXXX 2013-07-10 11:55:42
Log type: Firewall service
Status: You were not connected because a duplicate name exists on the network. If joining a domain, go to System in Control Panel to change the computer name and try again. If joining a workgroup, choose another workgroup name.
Rule: VoIP Policy: Publish internal SIP proxy
Source: External (XX.XX.XX.XX:5060)
Destination: Internal (XXX.XXX.X.XXX5060)
Protocol: SIP Server
Additional information
Number of bytes sent: 0 Number of bytes received: 0
Processing time: 0ms Original Client IP: XXX.XXX.X.XXX
As soon as the original outbound connection is CLOSED by TMG inbound calls start to work again.
We are on version: 7.0.9193.575 - with latest service pack and hotfixes installed. ANY suggestions would be appreciated.
PS. I have already reviewed our internal DNS server 10 times for dupe names, there are none. .DS