ISP blocks the use of ssh?
Here's a part of my remote machine's /etc/ssh/sshd_config:
Port 22
Port 443
In other words, I connect to my remote machine at port 443, which is usually used by HTTPS.
ssh [email protected] -p 443
I've found that most places that employ traffic filtering won't mess with HTTPS (or traffic on HTTPS' port).
1) Ask your ISP (consult their T&Cs etc)
2) Run a simple service (e.g. echo service) on that port and try connecting with telnet client or netcat. SSH is more complex to diagnose, so start with something simple.