Possible port problem !!

[JEA]

Hi Peter,
We have been using JoinFs for ages now with no problems at all. However, due to circumstances, certain aspects have changed. I have built a new computer, and also my residency chances monthly. One of my group has moved to Lanzarote from the UK, and now runs through a third party server. I understand he has asked for ports to be forwarded, and that has been done.
I, too, have to run through a third party server. (Not a problem when I used my laptop, FSX-SE and JoinFS)
Not wanting to take up too much of your time I will quickly describe the problem we are having.
I will call us A, B and C...... Person 'A' has a standard BT Infinity BB line.
A hosts a session, B and C join. A can see B and C, B can see A, but not C. C can see A but not B.
B and C cannot be joined by any if either host a session.
So, as a trial last night, we decided to try to join a public server in the Hubs list. This was successful, and we all saw each others aircraft. So we tried a second hub, and all joined that successfully, with full visuals.
We are baffled.....can you shed any light, please.
Many thanks in advance,
Kind regards,

Tony

[ATC Roo]

B and C cannot be joined by any if either host a session.

I would say port issue on their end.
All agree to the same port and see if manually setting it in the JOINFS settings works?

So, as a trial last night, we decided to try to join a public server in the Hubs list. This was successful, and we all saw each others aircraft. 

Has A tried hosting as a hub?

This sounds like the LAN issue where everybody connects to a server A is running on a different PC.
A connects using a local IP but doesn't see everybody.
If A connects to somebody else using the server, A sees everybody.

Unless A is able to connect to B or C, you will need to meet D, who also has a good internet connection with the correct port forwarded.

Ask D to host.
If A, B and C connect to D they should see each other( as when you all connected to the Hub).

If D wants to see everyone try...
A connects to D
B connects to A
C connects to D

My thinking is that A will pass B for D to see.
D will then pass B for C to see.
D can then pass C back for A to see.
A can then pass C back for B to see.

Just a theory....