Short answer: FIFA Street 2 (2006) has no official online multiplayer. It predates widespread console online infrastructure.
Local Multiplayer (Original Experience): Supports 4-player offline matches on one console. The intended way to play with friends.
Emulation + Netplay (PC Only, Technical): Use Dolphin (GameCube/Wii) or PCSX2 (PS2) emulators with netplay features (e.g., Dolphin's Netplay, Parsec). Requires:
Third-Party Tunneling Services (Risky/Unreliable): Tools like XLink Kai or custom VPN setups might bridge local multiplayer over internet, but success is rare, often violates Terms of Service, and exposes network security risks.
FIFA Street (2012) / FIFA Street (2014): Feature dedicated, stable online modes (ranked/unranked matches, lobbies, tournaments) on PS3/Xbox 360/PC.
Volta Football (FIFA 20–23): Integrated street mode in main FIFA titles with full online ecosystems.
Street Power Football (2020): Arcade-style street football with online multiplayer on modern platforms.
Recommendation: For a hassle-free online street football experience, play a modern title. Reserve FIFA Street 2 for local couch co-op nostalgia.