multiple l2tp from same public IP to same server issue

RouterOS General
1

I have an issue with l2tp/IPSEC vpn.
I have a mikrotik connected via vpn to the vpn server (mikrotik as well).
If a user connects with his laptop from the same public ip to the same server it drops the initial mikrotik vpn connection.
The user had it to his laptop to use it when is out in the road but accidentally he connected while he was in the office dropping the vpn connection of office towards the vpn server.
This may happen also if 2 users connect to the same vpn server while behind the same NAT in other words from the same public IP.

Any ideas?

2

http://forum.mikrotik.com/t/multiple-road-warrior-l2tp-ipsec-clients-behind-nat-solved/118206/1

http://forum.mikrotik.com/t/l2tp-ipsec-several-connections-from-to-same-ip-addres/71519/1

3

in other words we need to choose a different vpn solution…
the working but slow sstp or the ovpn?

would the caller ID type help at all?
setting ip address → number
and/or one session per host options of l2tp server?