Update: Also check out my full ADSL setup over at this link.
My search for the ultimate router started when had a problem where my basic ADSL router would die with perfect regularity if I left a torrent running overnight. After some research, I came to the understanding that Bittorrent asks a lot of a router. By design Bittorrent opens a heap of connections, and also hops around between connections very frequently, dropping and adding new ones all the time. Without going into the gory details of Network Address Translation (NAT), I can say that Bittorrent tends to load up router NAT tables pretty heavily.
So I went searching, and came across this page at Tom’s Networking. “Great!” I though, “here’s the clearest indication of P2P performance of different routers”. And off I went to order a Netgear Rangemax 240. It even sounded fast. However, following a few nights and days of testing, the Netgear was sent back for refund. Basically with Bittorrent running, I could browse two or three websites, and the fourth site would simply not respond. The DNS would resolve, but the connection would timeout. Crazy thing is that I could still browse the original two or three websites with no issues. I can only presume the NAT table system was dying horribly.
After further research, I read of some users who were having great success running customised firmware on Linksys routers. The price of the Linksys WRT54GL (the ‘L’ suffix stands for ‘Linux’, meaning these particular models support custom firmware), was so good that I figured I couldn’t go wrong at least trying it. I grabbed the router and uploaded a copy of the DD-WRT firmware. There are other custom firmware options, but it seems DD-WRT offers the simplest interface.
The first thing I changed was the NAT table settings, increasing the table size from the default 512 to 4096, and dropping the NAT timeout from 3600 seconds to 90. In English this basically tells the router “store heaps of connection details, but discard them pretty sharpish if you don’t need them anymore”, which is exactly the behaviour we want with Bittorrent and other P2P apps.
The result? Bittorrent downloads are consistently 50-100kBps faster than I’ve ever had them, and web browsing is still possible with torrents running (well, unless of course our third-world internet is congested). The router is also as stable as a rock, and the custom firmware offers so many tweaking options that I can’t imagine it being unable to deal with anything thrown at it. Heck if you want to sell WiFi access to your neighbours it appears to only take a couple of clicks!