Neil,
If your OBi box won't register, you have a different problem. You probably have your
VoIP.ms SIP credentials incorrect. The only difference between
Montreal3.voip.ms and
Montreal2.voip.ms is the location - which may effect how well the voice quality sounds but not the box registering in the first place.
Once you have the correct SIP credentials (the user name and password for your SIP account inside the
VoIP.ms network, not the same as your login to their portal), you can register to ANY of their servers. Meaning you should be able to register to
Montreal3.voip.ms just as readily as you can register to
tampa.voip.ms.
There is no need for a custom configuration in 99% of cases on
VoIP.ms. Just select them as the service provider in the ObiTalk Dashboard during setup and pick your regional server (Montreal1 or Montreal2). 3 and 4 just give you additional choices in case your ISP is having trouble reliably routing traffic to 1 or 2.
}Davoice