ios Muliplayer策略：使用ARC发送数据包（无结构）

I'm starting a multiplayer game, but the examples show passing a NSData object that was created using a structure. With ARC though, I can't use C structures. (correct?) It seems that I'm supposed to use objects instead of C structures using ARC. But how do I send NSData packets of objects? I'm starting a multiplayer game, but the exampl