I am having a problem with VPN, I currently have L2TP set up but the problem is while im working in the other office they have the port closed. They only have the following open:
Open TCP Port: 22 ssh
Open TCP Port: 23 telnet
Open TCP Port: 80 http
Open TCP Port: 443 https
Is there another way of setting up a VPN, for example a HTTP based VPN how can i set up a VPN with the ports open?