Friday, May 25, 2007

The LAN in LAN Party

While electricity may fuel a LAN Party, it needs one more thing- The LAN. What would a LAN Party be without its namesake? So to add this spice, here is an overview of pieces you need. Many of these items will be discussed in greater detail later.

Table Switch
For a small LAN Party this may be the only piece of networking equipment you have to buy. It splits your internet connection into enough pieces for every one at the table to have one. I recommend getting a 24 port switch with at least one gigabit uplink port. For my LAN, I use DELL 2324's. They are fairly cheap and good quality. You can also buy other brands like Netgear or D-Link. At a larger LAN Party (greater than 24 people) table switches just become a small part of the network layout. As tempting as it is, avoid switch with even more ports like 36 or 48. Trying to squeeze more computers on to one switch will create a need for longer cables and an even bigger mess. Keep in mind with a 24 port switch like mine, 24 PCs are sharing one gigabit uplink but on a switch with more ports, more computers are having to share that same uplink creating the possibility for a traffic jam.

Another consideration when buying a switch is to make sure that it is non-blocking. This means that it has the capability to switch all of the traffic it receives. While common today, some older switches don't have this feature. Sometimes the switch's description will only show the switch's switching capacity. To tell if is non-blocking, add up the bandwidth of each port and times it by 2 (for incoming and outgoing). For example- the Dell 2324 has (24 x 100 mbps) + (2 x 1000 mbps) so add this up and times it by 2 to get 8.8 gbps (8,800 mpbs) and if this equals what the stated capacity is, the switch is non-blocking.

If you are on a budget, switches this size are easy to find on eBay for good prices. I have gotten good deals on a lot of my equipment by searching eBay but always check to make sure you only buy from reputable sellers.

Core Switch
At a large LAN Party, you may have several table switches and they all have to be linked together. This is where the core switch comes in to place. The core switch becomes the central component of the network that all the other devices connect to. It is best for this switch to be full gigabit for maximum network speeds and super low pings. In the past, I have used a DELL 2708. I originally picked it because it was the cheapest gigabit switch I could find that offered some management capabilities. I also got this one off of eBay. It has worked well but It's 8 ports are becoming limiting as I have more game servers and table switches to connect to it. For LAN-O-THON v4.0, I'm watching eBay for a used 16 or 24 managed gigabit switch and my 2708 will become a server switch.

Server Switch
This switch isn't necessary unless you are having a large LAN Party you have more dedicated servers and table switches than have ports on your core switch or there may not be enough space near the core switch to place the dedicated servers. The server switch then becomes a offshoot of the core switch, kinda like a table switch but for the servers. It should be full gigabit like the core switch to prevent network latency (high pings).

Often the only internet connection available only supports one computer (like a dsl or cable modem) and you need to intelligently split the internet connection into multiple ports while appearing to be only one machine. This device is commonly called a Router but it is made up of several parts, the NAT, the Firewall, and the DHCP server. The DHCP server assigns each computer on the network its own IP address to use. This help people automatically connect to the network when they plug computer in so no manual configuration needed. The NAT merges the data from all of these unique address into the single address the router uses to connect to the internet. The firewall sits between these two parts filtering the data to provide network security by preventing unauthorized machines from gaining access.
For a small LAN Party (10 or less seats) a household router that you may already have around will work fine. For events in my dorm room, I use a Netgear WG614 but once you add more seats, a more industrial solution is needed.
For my big events I use an old PC running pfSense. pfSense is a highly optimized FreeBSD distro for creating a dedicated router. It can handle 200mbps+ and has a ton of features. The old PC I run it on is 700mhz Celeron with a 256mb of RAM and 2 Intel gigabit network cards and this is more than enough computing power for most events. pfSense s easy to install and setup and I'll create a Install guide in the future.

Cables- The Last Link
To connect all of your network together- your routers, switches, servers and guest's PCs, you use cat5e cable. You can buy this cable ready made or you can buy a roll and make the cables yourself. For a large event, this is often much cheaper and allows you to create just the length cables you need, reducing the tangles of wires on the tables.

There are two main types of Cat5e cable: stranded and solid . Stranded cable has conductors (the individual wires in a cat5e cable) that are made up of multiple thin copper wires. This creates a very flexible cable great for linking your guests computers to the table switches. They typical have ticker jackets making them able to withstand a lot of handling however, the down side is that data can degrade over runs of cable over 50 feet long. This where solid cat5 comes in. Solid cat5's conductors are made up of a single, thicker piece of copper. It is good for making long runs of cable like between your table switches and core switches because data doesn't degrade as it travels over it but is less flexible.

Cat5e's outer coating also comes in several different types: PVC, Plenum and LC (Low Combustion). PVC is the standard and cheapest and what you're probably going to want to buy. The other 2, Plenum and LC are designed for office buildings and data centers where building codes specify their use to prevent fires from spreading when cables are hidden in walls and traveling between floors. These two types of cable both melt instead of burn when exposed to an open flame, while they are safer, they cost 2 to 3 time more and for a temporary event like a LAN Party where all of the cable is exposed it's overkill.

LAN Cables are easy to make. See my guide How to: Make a LAN Cable for step by step instructions.

If your look to buy Cat5e cable on the internet I recommend a site called Deep Surplus. They sell a variety of network related products at great prices. I have bought many items from them and they are fantastic plus every order includes a free bag of candy. Sweet!

Optional Elements

Web Server
Having a dedicated webserver is almost required for a large LAN Party. Running great software like ALP (the Autonomous LAN Party, free) allows you to organize your LAN Party, run tournaments, schedule events, jukebox and more. I also use the computer as a file server for hosting critical game patches and custom maps. For my server, again I use an old PC, this time its a 733mhz PIII with 512mb of ram running FreeBSD but you could you any flavor of Linux or even Windows. My magic 8 ball sees another guide in the future.

Game Servers
Any size LAN Party can benefit from running dedicate game servers. A dedicated box is more stable and easier to fix when something goes wrong. I tend to just borrow a friends computer (who isn't a gamer) to use at the event (just be careful not to cause any ill harm). For my favorite Valve games like CounterStrike: Source and Half-life 2: Deathmatch you can use Valve's free Source Dedicated Server. It is easy to install and setup and runs on Linux and Windows. A guide for getting this setup is planned too.

How it all goes together
Have a look at this diagram....

It basically goes like this Router-> Core switch->table switches. Once you get all of your cables run, like extension cords, it is a good idea to tape these cables down to the floor with blue painters tape for safety. When possible, it is a good idea to keep electrical and data cords 12 inches away from each other to prevent interference. If the have to cross make sure they are a 90 degree angles. Have a look at the picture right to see my setup.

Have a question? Did I leave something out? That's what the comment box is for.

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