We have a few small sites that each have a Draytek Vigor (various models) which are configured to create a company VPN. It's setup as follows:
Branch 1 (192.168.1.0/255.255.255.0) Accepts Incoming Branch 2 (192.168.2.0/255.255.255.0) Dials Out Branch 3 (192.168.3.0/255.255.255.0) Dials Out Branch 4 (192.168.4.0/255.255.255.0) Dials Out
There is a IP phones system (BCM 50/Avaya) running in Branch 1 on 192.168.1.210. I would like to be able to put an IP phone in one of the other branches that will use the VPN tunnel to connect to Branch 1. I believe, from the engineer that installed it originally, that this is a common thing to do. However, all the documents I have read state that the Branches must be on different subnets.
So, how do I make the IP phone work if it's on a separate subnet? Would it work correctly if I manually set the IP of the phone to 192.168.1.XX from a Branch other than Branch 1?