a sneaky sniper
Critical Edge Forum
MAR 2015

There are at least two available options for multiplayer:
http://www.battlelog.co/
http://www.bf2hub.com/home/

According to information found in the battlelog.co forum, users are able to retrieve old BF2 accounts after the fact, even if they had not saved/ported them prior to GameSpy being shut down.

BF2_SPX_01.zip mod (1.7GB)includes the BoosterSP mod which provides an offline 1.41 SP game playing option for all but the non-SF maps

BF2 Hub retrieves your BFHQ BF2 stats hassle free.

Port forwarding bare minimum to run BF2 MP with BF2 Hub:
UDP 16567
TCP 28910
TCP 29900
UDP 29900

To speed up loading of the BF2 Hub prompt, add TCP 29901.
with router firewall disabled = 20 seconds delay
with medium security + port forwarding - TCP 29901 = 55 seconds
with medium security + port forwarding + TCP 29901 = 32 seconds