Today I installed an IP PBX at a clients location and estableshed a PPTP VPN tunnel at the remote location, Data flows perfect however the phones dont work properly. For some reason the PBX thinks that all the phones connected through the VPN are coming from the same IP address. The PBX Shows all the phones having the IP address of the Mikrotik interface. any Ideas why this is happening?
Thank you
Because you probably use NAT masquerading from Local to remote PPTP [and also from remote to local?],
you must routing instead of natting.
eg:
remote pbx = 2.3.4.5
remote PPTP IP = 1.1.1.1/29
local PPTP IP = 1.1.1.2/29
local ip range = 192.168.1.0/24
on local you must add this route
destination=2.3.4.5 gateway=1.1.1.1
on remote side you must add:
destination=192.168.1.0/24 gateway=1.1.1.2
and you have done without natting any.