I am in the early stages of planning a small RTS game using XNA. My concept revolves around 2-4 players on a local network, each controlling around 10-15 units. I've been reading a lot about RTS client/server relations on both the forums, creators club website, and elsewhere, trying to educate myself as much as possible before beginning. In addition, I also intend to implement as much of the general concepts as possible in my test project (a stratego clone). Now before I begin to implement the XNA 2.0 networking, I was wondering if anyone had input on pitfalls I might encounter. Is anyone familiar enough with the XNA networking framework to know if it will be able to handle an RTS type game? I don't suspect it will struggle with the load, as I don't intend to have a "1,000 archers" type game. My greatest concern is that I will struggle to maintain lock-step synchronization with the XNA framework. Before I begin to implement anything in my stratego test project, I want to be certain that XNA is an appropriate technology to use for my future rts project. Any input? Thanks!

[Edit: Just re-read that you plan to do this on a LAN; not online. In that case PC to PC LAN connections don't require any subscription so I'd suggest going with the LIVE networking API inside of XNA. I'm leaving this text for others, I guess]

If you use the built in LIVE online networking, be aware that you basically can't redistribute it at this time. Currently access to the LIVE online networking requires that the player be subscribed to not only LIVE Gold but also to the Creator's Club. That said they are opening up Xbox LIVE Community Games at the end of the year where anyone can download and play XNA games (including those utilizing the networking) directly to their Xbox 360s. This is great if you are shooting for Xbox 360, but does nothing for you on PC.

If that doesn't sound good for you, you may want to consider another networking API such as Lidgren. There's a tutorial over on Ziggyware.com to show how to integrate Lidgren with an XNA game.

If you aren't worried about it, then yes, LIVE networking is going to be fine for this sort of game. A large portion of your game's network performance will come down to you; not the networking API. It depends on how much data you send from machine to machine and how frequently you do that.