Quote:My current reality is that P2P allows for a higher maximum number of player than Server-Client does in the case we don't use dedicated servers

Actually, the one crucial assumption is that everyone has the same upload limitations. If that is true, then P2P will allow larger amounts of clients than C/S -- but only up to some small amount of clients, like 16 or 32, because limited upload is, well, limited :-)

As soon as you can find one user who has better than average upload, then C/S gives you a lot of benefits, including an authoritative server, larger player counts (even for players with much more limited upload), etc. And that server is, generally, a normal playing doing "hosting," not a dedicated server paid for by the game publisher.

When it comes to RTS games, I'm not so sure they are all P2P -- if you look at Starcraft, for example, it has a clear host, and when on the Internet, it goes through battle.net to avoid NAT problems. I wouldn't be surprised if it actually was C/S topology with the "host" as the server. However, it doesn't matter much, because with 4-8 players, neither model is all that different in network bandwidth usage, so other implementation worries probably weigh more heavily.

Quote:Original post by NickS
* Donnybrook is a collaboration between Microsoft Research and the Carnegie Mellon University, the system was at the basis of simulation results involving battles of approximately 900 players interacting simultaneously.

Where do you get the number 900 from? From the papers linked so far in this thread (and all the other papers I have found), it seems to me they're testing only 2 players at a time, with 30 bots (i.e. 32 players in a single game).

Quote:Original post by NickS
* Players are satisfied by Donnybrook in a low bandwidth environment as they are by Quake III in a high-bandwidth environment, e.g. a LAN.

That's still comparing Donnybrook P2P in low-bandwidth to "naive" P2P in high bandwidth, though. It's not comparing Donnybrook P2P with C/S. Also, the "low bandwidth" Donnybrook is 108Kb/s upload which is already at the limit of many people's broadband plans - that is, even Doonybrook does not scale past 32 players on a standard broadband plan*.




*Technically, Donnybrook bandwidth requirements are supposed to scale better than linearly in the number of players, but it's still not "free".

Another thing to consider is the complexity of implementing the Donnybrook solution, compared to the way it was done in "normal" C/S Quake 3. The way it was implemented in C/S Quake 3 is practically the most naive solution possible while still providing for 32 players (in fact, if you read what he says, it seems Carmack simplified the implementation a lot since the original QTEST).

Donnybrook is far more complex than the C/S implementated in Quake 3, and it doesn't seem to work any more efficiently than C/S quake.

Quote:There is a growing desire to use the machines of participants themselves rather than separate dedicated servers to provide resources for serving games.

Do you have any support at all for this statement?

In my experience, it used to be that users would host, because hosting was expensive. These days, hosting is cheap. Thus, /users/ will pay for dedicated servers (just jump on any C/S:S session -- almost all the servers are hosted at ServerBeach or Gameservers or whatever).

When it comes to large-scale P2P solutions, I still recommend you look into the VAST project. However, it's also been my experience that when people try to really deliver large systems on P2P, they end up adding more and more C/S-like systems, until suddenly the P2P turns out to be something like a C/S set-up with P2P-elected dynamic servers...

Finally, Xbox Live! tech cert requires that you work well in multiplayer on 64 kbps upload. While some users may have 768 (DSL generally comes with 384), you're not allowed to use that in your normal multiplayer scneario.

Hi guys, I'm the developer of the earlier mentioned Stickman Warfare, one of the banned guys from here has invited me to this topic, so I'm just here to share my experiences.

I've been doing stickman for like 3 years now, and i have to tell you, P2P is a heavy PITA. Not only it has sync and connect issues, it's really easily hacked. But the reason I made it this way is that its absolutely free to host, since a P2P NAT introducer doesn't use too much bandwidth OR CPU, so it can be run from a really cheap (free) virtual server at my friends computer.

Apart from the NAT stuff, i found P2P a lot easier than C/S. Simply because the player only has to care about his characters physics only, and it doesn't have to synchronize with the server, compensate the roundtrip time or anything like that. Only the priority system was a bit difficult/complicated until i fine tuned it. Now the network code is no more than a few thousand lines of PASCAL code.

Oh, and with the right priority system, you can have infinite players using only 7kBps upload. (yes, stickman did not lagg at 70 players and its completely scalable)

OF course, this cannot be applied to a commercial game because its so much less secure than C/S that hacking is inevitable, only delayable (memory protection, debugger detection, etc... but thats only against Cheatengine using script kiddies).

Well, thats all i could think of.

P.S: Its been a long time since i used my English...

EDIT: Forgot to mention, my P2P implementation is rather unstable, there are times when you don't connect to the clod or suffer severe lag. Thats completly my fault, not the P2P's.

EDIT2: I just read th whole topic, and I dont know the guy, please dont ban me :P. I dont consider my game great or innovative, it is just your average P2P shooter.

Quote:stickman did not lagg at 70 players and its completely scalable

What happens when 100 players all congretate in the same spot?

Quote:stickman.hu <=my game (please tell me your opinion about it)

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