General LAN questions

Hi all

im organising LAN Party and wondering how much users my router Linksys (model#: BEFSR41) can support if it only act as a DHCP server

i went on Linksys website and it says that it theoretically support 253 users but im sure it wouldnt be able to

had to mention...
the router acting as a DHCP only is directly plugged into the principal switch that manage others uplinked switch...

is it ok? should i use 1000mbits uplinks between switch?
anyway got some other questions ill ask later

[Uranium-235]

why not just plug all users into the switch?

cause actually i dont have enuf equipment
cant plug all user on one switch

so i got few uplinks.. bout 8 to 24 users per uplinked switchs. Tough using 1000mbps uplink port between switch would be usefull..
still dont know anyone can gemme advice ?

think bout it... theres gaming, file transfer, internet...
i would run dedicated servers on 100mbps plugged into the main switch, my router acting as DHCP server only, maybe another router only for the net but it may be useless.. cause im thinking to make a public lan in college or something so i guess the net is also routed...

[Omega]

If your device says it will handle 253 users, then that's what it will handle. I'm not sure how gracefully it will handle them if you have that many, and they're consistently unplugging/plugging into the network (because of retention of DHCP leases), but it should be fine up above 100 users. Gigabit uplinks between switches is a good idea, to prevent bottlenecks, especially if some users want to transfer files, while others game, but I wouldn't recommend spending an extra few hundred dollars for this. If you're running some more advanced switches, you could also look for port trunking abilities, rather than a giabit ethernet module. In all fairness, most LAN gaming doesn't take up all that much bandwidth. If you were *just* concerned about gaming, you'd likely be fine with 100 mbps uplinks, assuming full duplex. If you're hoping for good file transfers between switches in multiple instanes, I'd recommend higher capacity uplinks.

i know that lan gaming doesnt take that much
but for sure whenever theres Lanparty theres file transfer

also what the trunk port option ive already read something bout it but dont really remember..
is it kinda priorities managment or something?

Port trunking involves uplinking switches together using multiple ports, at their maximum speed. Basically this means you would could use two (or three, or four, or more, depending on switch) ports on each switch, trunked, for maximum throughput of 400 mbps (100 mbps + 100 mbps upstream, 100 mbps + 100 mbps downstream), again, assuming full duplex 100 mbps Ethernet.

Prioritizing ports is something different, but can be useful in certain situations. For example, you may want to give a dedicated game server high priority on a switch, so then the people doing file transfers can have higher latency, and slightly slowed transmission. This is really only going to have an effect if you're using extremely high amounts of bandwidth on the switch, though. Additionally, some switches allow manual specification of 10, 100, or auto-sensing speeds per port. You may want to restrict people to 10 mbps if there's game slow-down.

wowerz

im learning too
it always is a good time to learn

Yup! ur right evil

thx for the info omega
by the way is there anyone could gemme exemple of a good switch setup for a Lanparty of 100-200 users

a good setup to be performant, high bandwith, with less bottleneck as possible

I hope I can explain myself so please be patient.

Try to keep the load balanced so all computer have the same number of hops to just about any other computer. This would mean you may have one or two master switches that "farm out" to the rest. This means for 200 plus users about 17 16 port switches (used for simplicity Doubt if this will be your setup. Set up one switch as the master. Then use one port on each to tie back to the master this leaves 15 ports on each switch or 240 ports to plug computer strait into. You could even pull one switch, have 225 ports and plug the main server directly into the Main switch. Then every computer would have 2 hops to the server (secondary switch to main switch) and at most 3 hops to any other peer on the network (secondary switch to main switch and to the other secondary switch).
What you want to avoid is chaining, one switch plugged to another, to another to another. Traffic is split between available ports and divides your theorortical bandwidth. an example.

main switch 4 port 100 Mbps
secondary 4 port 25 Mbps (because it can only get 1/4 of the main switch's data
third 4 port 4.25 Mbps (Since it is only connected as as 1 of the other 4 ports It will still only get 1/4 of the main switch's speed.

It just keep's degrading very fast and even more so If your dealing with large switches. I hope that makes sense. Some if it's fairly simple but it can get complex quick.

[Omega]

What you really have to be concerned with is uplinks between switches. An ideal situation would be a 200 port 100 mbps switch...but good luck finding that. Next, if you truly wanted equal bandwidth for everyone, would be a central gigabit switch, branching out to switches with a gigabit uplink, and 10, 100 mbps users per switch. That way, theoretically everyone could send/receive at full bandwidth (unless 199 users are simultaneously trying to download a 10 GB file from the 1 other user...then you get into issues of how switches handle frame queuing, but regardless, common sense states it won't work). You'd probably want to throw anything that was a dedicated server (file, or game) onto the gigabit switch as well.

If you were trying to do this 100 mbps switches without gigabit, it's another issue. While there are obviously multiple ways to go about doing this, here's my idea:

Have a central 24 port 100 mbps full duplex Ethernet switch. From that, branch out to 17, 12-port switches (or a 48 port switch going out to 40, 6-port switches). You'll want to minimize the amount of traffic having to travel across an uplink port (this means the least amount of people per uplink possible). Simply stated, however many users (x) per uplink are sharing a specific amount of bandwidth (y). So bandwidth/user = f(x)=y/x. The limit of the function as x->infinity is 0 (threw in some calculus there too).

Anyway, I have to go, you get the basic theory, hopefully.