Observers, Blizzard, and Esport - Page 3

Badred

Canada129 Posts

September 06 2010 05:26 GMT

#41

On September 06 2010 11:00 gondolin wrote:

To be fair I never wrote huge multiplayer project using udp, so I may be wrong about this, but in my experience udp packets eventually do arrive (except when there are some problem with the MTU and thus but it will be detected at the IP level anyway).

UDP packets are not guaranteed to arrive - that's exactly why it's "faster" than TCP: there's no confirmation of packet arrival sent back to the sender. TCP will keep sending the packet until it receives confirmation of it's arrival, while UDP just sends once and assumes it got there. It's possible, and indeed likely, that some UDP packets will never arrive. Any sort of guaranteed delivery in UDP would have to be manually coded into the software (or use some sort of library that handles that for you).

Really the protocol used isn't the issue. The actual amount of *latency* between the two protocols is the roughly the same as long as you're not dropping too many packets, it's just that TCP just requires slightly more bandwidth and has more overhead (as does UDP if you're using the aforementioned libraries to ensure delivery).

This page has a fairly good analysis of the two protocols: http://www.devmaster.net/wiki/UDP_vs_TCP

Lighioana

Norway466 Posts

September 06 2010 05:33 GMT

#42

Good post. Still, I'm afraid Blizzard will not do it.

Subversion

South Africa3627 Posts

September 06 2010 05:49 GMT

#43

isnt this exactly the same as huk's thread?

gondolin

France332 Posts

September 06 2010 10:41 GMT

#44

On September 06 2010 14:26 Badred wrote:
UDP packets are not guaranteed to arrive - that's exactly why it's "faster" than TCP: there's no confirmation of packet arrival sent back to the sender. TCP will keep sending the packet until it receives confirmation of it's arrival, while UDP just sends once and assumes it got there. It's possible, and indeed likely, that some UDP packets will never arrive. Any sort of guaranteed delivery in UDP would have to be manually coded into the software (or use some sort of library that handles that for you).

Yes, I know they can not arrive, but usually they just get delayed, and arrive in the wrong order. The packet get loss when one router is overloaded with data and start dropping packet. As I have said, in my experiments, this happened very rarely, but that was because it was through a local network, with not saturated routers. I can guess than in a multiplayer game like scII, the packets will go through more congestionned routes, and they can be lost more easily.

If you have some data about the rate of packet loss using udp via internet (rather than an intranet), I would be interested.

The actual amount of *latency* between the two protocols is the roughly the same as long as you're not dropping too many packets, it's just that TCP just requires slightly more bandwidth and has more overhead (as does UDP if you're using the aforementioned libraries to ensure delivery).

Yes, but the point with udp is that you can just send the datagram and don't care to what they do afterward. If you are sending them to observers, you don't care if they lose some packets and desync (if that happen rarely). And if they lag you don't notice it at all. With tcp the reliability is implemented on the os tcp stack, so you can't do the same thing.

gondolin

France332 Posts

September 06 2010 10:42 GMT

#45

On September 06 2010 14:49 Subversion wrote:
isnt this exactly the same as huk's thread?

My post is from earlier, and is more focused on providing a technical solution to the observer problem.

Random()

Kyrgyz Republic1462 Posts

September 06 2010 11:43 GMT

#46

On September 06 2010 19:41 gondolin wrote:
Yes, I know they can not arrive, but usually they just get delayed, and arrive in the wrong order.

The protocol does not guarantee that all the packets will arrive, so you cannot just tie the functionality of your software to what "usually" happens in perfect conditions.

vol_

Australia1608 Posts

September 06 2010 14:20 GMT

#47

With Cataclysm beta going on Blizzard is probably more worried about their gift that keeps on giving, WoW..

kariido

Saudi Arabia179 Posts

September 06 2010 17:48 GMT

#48

Good idea, won't be implemented, sorry. B.net staff/Blizzard just doesn't give a hoot and you know it.

If LAN, cross-region play, and chat channels were done away with for no reason whatsoever (don't you dare say piracy or spammers as that can be easily dealt with by authentication/banning) why would they bother with rewriting code just so you and few other nerds get lag free games? Since the majority (read: Casual gamers) are happy and are still buying the game they don't see a need for wasting money on modifying anything or implementing any features that have been overlooked or plain butchered from the start. Our opinion simply doesn't command enough market presence for them to bat an eye at our displeasure.

Also, instead of working on a released game that is still selling well, they're main focus now is on WoW Cataclysm which will bring them far far far greater revenues than SC2.
The point at which these threads and/or complaints would of made a difference was during the BETA but every similar thread with a legitimate complaint (read: not MBS/Smart Cast) was bombarded by Blizzard fanboys who would flame thread starters for whining and preach about how the game was still in BETA and that the release version would have any and all problems fixed and dealt with. They were wrong and now we have a multitude of problems on our hands that won't be dealt with any time soon.

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