(I don’t typically implement my own NAT punchthrough — working on consoles it is already provided. If I were developing code for PC or Mac I’d licence some tech to do it, or go client/server with dedicated servers…)

cheers

How does UDP get through routers without manually forwarding ports? I understand that it’s not really the topic of discussion here, but I feel that someone here could provide a better explanation from a developer perspective, then most google searches provide.

Thank you.

And incidentally, as the Guild Wars programmer who wrote the client->server communication protocol, the server->server communication protocol, and the low-level network libraries (among other things), I want to caution folks about making assumptions about why we chose to use TCP for Guild Wars (or why Blizzard chose TCP for WoW). We didn’t pick TCP for Guild Wars because it was unequivocally the best choice; it was a trade-off.

It probably warrants a blog article, but the reason Guild Wars uses TCP is that I felt the labor required to write a reliable transport layer on top of UDP would take too long: we’d run out of money fooling around writing transport code instead of writing a game.

So I chose to write Guild Wars on top of TCP, and if it didn’t work out I could rewrite the client transport layer to use UDP. Fortunately TCP worked well enough for client->server code.

But there is a big downside to TCP that I should mention beyond what Glenn talked about: you lose control of when connections terminate. So if a router fails-over in your datacenter, or if one of your bandwidth providers fails, you’ll likely drop all your TCP connections traveling over that route. With UDP it’s possible to just ignore the loss of connectivity, wait for routes to re-converge through a different router or bandwidth provider, and keep going.

So in short, Glenn knows what he’s talking about!

A hybrid Action-MMORPG called TERA Online is nearing release, complete with the tagline “True Action Combat”. I’ve played in the public beta tests, and can personally attest to the legitimacy of the claim; the controls feel crisp and responsive. What’s even more interesting is that it is one of the first ‘action’ games to feature a persistent world, a la World of Warcraft, Guild Wars, and other more traditional MMORPGs. No lobbies, no rounds.

I did some googling, and it sounds like TERA uses both TCP and UDP to pull it off. Maybe I’ll try capturing some packets with Wireshark later (after double-checking the ToS to make sure I can do so) and take a look, but in the meanwhile, any thoughts on this?

Thanks

I am new to online Game development and I am trying to develop an online card game using ASP.Net MVC. I was reading your article on UDP vs TCP and some of your comments. You have explained it well to get basics of how both works. I understand for some games UDP will be the best choice. I am thinking to use TCP for the card Game. Is it a right choice and do you have good pointer which can lead me to right path.

Thanks and I appreciate your reply.
ssp