By default, GAS will utilize the Passive Port range of 30000-32000. Opening up the 2030-2130 (I would assume) would only affect the passive port range on THEIR server, if that's what they use.
During negotiation, GAS will tell their server to utilize port xxxxx (within the range mentioned above) to start communication (Data Transfer).
If you're connecting to THEIR server, then the issue might be that their Passive Port range isn't opened for them (Their Local) not yours. As a client, you don't have say-so as to which Passive port to connect to. That happens during the handshaking. As long as your client allows you to connect to them, you should be fine.