vMCD with Sip Trunks via vMBG no RTP Stream

[MitelEng23]

Hi Guys,
Got issue with sip trunks and audio, have no audio at all.
The current setup is vMCD programmed for Sip trunks with provider VoiceHost. The Sip trunks then go through the vMBG as a Sip proxy.

I have programmed it so far so that the link is up, in service and registered successfully. (Authenticated Sip Trunks)

vMBG link status is Green and saying is up, I can dial out to my mobile fine answer the call but then there is no audio at all, can see on a Sip TCPDump no RTP stream.

Wondering if this is a firewall issue? As the vMBG then points to the firewall which the firewall then has direct link to the Cisco Router provided by the Sip Provider and this router goes straight off to the external address.

vMBG setup is sitting in a DMZ

Thanks in advanced.

 

[bribob]

What brand of firewall are you using?

Can you capture packets on the SIP provider facing port of your firewall to see exactly what IP address (Connection Information) is being negotiated during SDP exchange?

Do incoming calls complete successfully and experience no-way audio as well?

Single network interface on the vMBG (server-only)?


-b

 

[MitelEng23]

Firewall is a sophox box.
I am not sure don't touch firewalls to be honest but I can get customer to do this for me.

I spoke with the Sip provider and they advised the seeing the IP address that they are trying to negotiate with is a 212.250.220.77 which is an address we are using for the Teleworkers external address they connect to from a MAS server.

Incoming calls don't complete I get Number not in use.

vMBG has just the one NIC yes server only correct.

I am going to see down and look at their firewall as seems like when sip calls coming in they pointing to the wrong address.

 

[MitelEng23]

I make small changes to the MBG and it allows me to make an outgoing call audio working both ways but then I redial or manual dial out again stops working no audio.

All I change is the Set-Side Streaming address from the internal Firewall to the Cisco ROuter which Sip provider has provided and this allows me to make a call once and then any other calls get no audio, I swap it back to internal firewall address and I do a sync to Mitel AMC and dial out this also works with audio ok. But then it stops working straight away after that first call is made.

Finding this very bizarre now.

 

[MitelEng23]

Got this fixed now on Outbound calls. Was port issue on the Firewall side checked them over with customer and advised they needed to open up more ports for bi-directional.

Only issue now inbound just getting Busy, but think that is issue with sip provider either giving me wrong number or could be firewall as cant see my call hitting MItel MBG.

 

[bribob]

Sounds like the customer needs to review the inbound NAT on their firewall and confirm that the external IP (assigned to the Sophox interface connected to the providers CISCO router) is configured to NAT directly to the internal IP of the vMBG.


-b

 

[MitelEng23]

Well checking the firewall all looks ok, when we call the number and look at the firewall logs for traffic we cannot see anything coming at all, but yet on mobile get 'busy'.
Raised it with Sip provider waiting on them to do wireshark trace to see whats going on.