IPSEC, remote network can only have 1 client connected

RouterOS General
1

I am using VPN phones that connect over a IPSEC tunnel.

The first phone works, but when i connect a second phone to the Mikrotik VPN (from behind the same router and on the same network as the other phone - same public IP), the first client looses connectivity.

So i can only ever have one client from the remote site connected at the same time - no good.

I am using the same shared key for all, if i change to different keys for different users will that allow more than one user at a time?

Or is this setup impossible with Mikrotik and do i need to look into buying a new box such as a sonicwall?

2

It is a limitation of linux kernel. You can run only one client behind the same NAT router.
As far as I know openswan and strong swan have the same limitations.

Solution could be to map L2TP to different port and use strict ipsec policy.