BWQ3DM Season 5

[old.Requ!em]

UDP

Originally posted by wz|Acronym
plus whatever the UDP header overhead is, which is less than 22 bytes that TCP inflicts; let's call it 8 (you need at least 8; sending address and receiving address, each being one word.)

You must also allow for length and optional checksum in the UDP header. The IP header ( UDP/IP ) adds an extra overhead as well. Example of a UDP/IP header follows:

IP: ----- IP Header -----
IP:
IP: Version = 4
IP: Header length = 20 bytes
IP: Type of service = 0x00
IP: xxx. .... = 0 (precedence)
IP: ...0 .... = normal delay
IP: .... 0... = normal throughput
IP: .... .0.. = normal reliability
IP: Total length = 180 bytes
IP: Identification = 16822
IP: Flags = 0x4
IP: .1.. .... = do not fragment
IP: ..0. .... = last fragment
IP: Fragment offset = 0 bytes
IP: Time to live = 254 seconds/hops
IP: Protocol = 17 (UDP)
IP: Header checksum = de8e
IP: Source address = 62.7.7.123, me
IP: Destination address = 213.221.174.66, them
IP: No options
IP:
UDP: ----- UDP Header -----
UDP:
UDP: Source port = 27950
UDP: Destination port = 27911
UDP: Length = 160
UDP: Checksum = 094B

[Edited by Requ!em on 13-03-01 at 14:11]

 

[old.VicNBob]

Acronym wrote:

8 players on a map, need 6 bytes to describe position/velocity per player (two three-byte unsigned ints as vectors) = 48 bytes;

About thirty fixed-location items; one byte for each, to tell the client whether they're there or not = 30 bytes

In the case of ra spamming at DM7, about 30/40 plasma entities at 6 bytes each (approximately 180 bytes);

Urrrrrrrrrgh
It's nowhere near that simple ;p

I just looked at the direction code - it's hideous ;p For network travel, all directions are mapped onto one of 162 predefined 'Byte Normals' - which can than be transmitted as a single byte. Positions are a bit less clear though, but I strongly suspect these will go as 3*32bit integers - 12 bytes. Which means 13 bytes/player and 13 bytes/bolt.

Players outside your PVS aren't sent even in snaps. Obviously a DM7 melee will often see all eight players in the same room - that's 104 bytes of snap.

Thirty fixed-location items - I hope to God ID have encoded this as bitfields, although I can't actually be bothered to check ;p - please let this be 4 bytes, or I'll end it all RSN. We can therefore pretty much ignore this. However, when added to sound triggers and other events, there's probably 30-odd bytes of 'assorted events'

Again, a plasma bolt is 13 bytes. Plasma fire rate is 10/sec. It takes about half a second for a bolt to travel the width of the RA room on DM7, so say 5 bolts per pg. firer existing simultaneously. IME, 4 is realistically the highest number of people firing pg at once in there - defenders will often favour rail initially, some attackers will come in with rockets and shotguns. So that's about 260 bytes / snap of plasma fire.

Serverinfos are only sent when they change. On OSP, that means with every frag. An OSP serverinfo is quite large - 400-500 bytes at least, I'd guesstimate from looking at Game Explorer; however, even in mass fights you rarely get two frags within a second of each other.

So, worst case:

104 bytes of player vectors
260 bytes of plasma vectors
30 bytes events
Bookkeeping overhead (round up to 400 bytes ;P)
UDP overhead max. 16 bytes.

416 * 20 (whatever your client snaps is set to, you never get more than sv_fps actual snaps, ie. usually 20) bytes in snaps = bit over 8k. This is worst case big plasma melee. 8.5k when you add the osp serverinfos. In melees therefore, ISDN will give up on deltas, and also start dropping snaps (or worse if you overdo your rate setting).

RE. packet efficiency in ISDN - ISDN adds a small packet-tracking overhead. I dunno what exactly this is in telephony ISDN - but I do know a bit of SS#7 which suggests to me this could well be about 12 bytes.

It's worth also bearing in mind that even on dual channel ISDN, individual packets are only sent at 64kbit/sec which means that packet size has an impact on ping which won't be helped at all by going 128k bonded.

Cheers,
Vic

 

[old.VicNBob]

Less Geeky / IRC llama-y post

Coupla things, now I've read the whole thread:

Q3Mexx1 - like it
Q3DM11 - love it, scene of the best teamplay I've participated in to date in TDM
CPM9 - NO NO NO NO NO NO NO NO NO!

Played cpm9 in wpdml last night - it truly sucks beyond belief as a teamplay map. When I first saw it, I immedeately assumed it was a FFA map, have played TDM on it I stand by that assessment.

Someone suggested sv_fps increase to 25/30 - NO NO NO! 30 would flood even rate 10k in melees, and 25 would strain it. See my previous post for sums. Single channel ISDN wouldn't stand a chance - looking at effective 25%+ pl in melees with sv_fps 25.

I've just thought of a possible theory for the lag experience. The kickback and firing rate from plasma and lightening are both enormous, and due to stabler connects broadbanders are likely to be more accurate with these (in particular they don't suffer as much from the packet size/ping link) - add this to prediction errors and bang! feels like lag. Might explain why I don't feel a huge difference between 128k and 64k ISDN - although I will continue to use 128k in leagues for those 4v4 plasma bustups One thing about this theory though - broadbanders should still feel the difference between ISDNer firing at them at broadbander - any of you c*nts find that? (I love you all really, honest, but reserve the right to swear at you lots on servers )

 

[old.saltire]

Maxpackets: rule is fine as is. As CM'er I have no pity for ISDN'ers, since I don't remember many rules pitying 56k'ers. And yes, as a 56k'er I did get lagged next to ISDN'ers. Yes, this is selfish, but to heck with it, this is online gaming. If you really want a truly even field, LAN.

Maps: CPM9. I'm so bored of the same old 6 maps its unbelievable, a case of lather-rinse-repeat. And imo it has alot to do with the recent bout of people/clans/organisers ditching Q3. Clan Wars are trying something different, and yes they got abuse, and yes some people don't agree with a couple of the maps, but it is at least trying to breathe a little more life into the game. And I can't abide clans saying that they have to learn all over again - thats what its all about! Yes, its custom built, yes, it means you have to download it all by yourself, but come on! 6 maps over 9/10 weeks? Pfft. And if q3mexx1 results in close games, great, keep it in.

Self adminning: would probably be more hassle than its worth should 'issues' arise. It can be bad enough with an admin there as it is.