Trouble seeing other players on Monster Hunter Freedom

[AdamN]

What is BT homehub? are you using 4G internet connection?

If you use mobile data connection such as 3G/4G you won't be able to use public Adhoc Server such as socom.cc, because most mobile data ISP will blocks incoming data from the internet.
The only workaround is by using VPN, which mean you will need to use built-in Adhoc Server and can only plays with people connected to the same VPN with you.

There is also Port Offset issue, you need to make sure everyone playing together to use the same Port Offset value, the default is 10000 but some players might change their Port Offset, thus won't be able to see each other.