They had an old, discontinued VBP installed, which was replaced by a 7301 Series. (Firmware 15.8.10)
Endpoints (several Group Series 500 and 300 as well as RP-Desktop and RP-Mobile Clients) are registered with the VBP.
Communication also happens with external Endpoints (H.323 and SIP) and Services (Bluejeans and GoToMeeting).
The VBP is Deployed in a DMZ (with a static external IP address).
With the Old Deployment the customer was limited to H.323 but with the new VBP's "Embedded SIP Server Mode" the customer want's for the Endpoints to be enabled for SIP as well.
Conferencing between registered endpoints works fine (SIP as well as H.323).
Making and Receiving H.323 calls between external and registered endpoints works as well.
Using SIP however, no calls from external endpoints seem to reach the registered endpoint. Calling an external endpoint from a registered Group via SIP works fine however.
The first thing I checked was the Firewall(s), but while we the see traffic, none of it is beeing blocked.
In my mind the next place to ycheck would be the VBP, to see if any communication reaches it, but I could not find any Information on something like "SIP Server Logs" or the like. Will unsuccessfull calls be logged by the VBP? If so, where can I find this information?
I stuck to the Admin Guide for configuration as much as I could, but it's painfully unspecific at times. Is there any other / better Information on the Video Border Proxy. A Best pratice Guide or something like that?