How to make a full-featured server from a cheap and simple router.

Introduction

The first router that came to me was the D-Link DI-524, I didn’t have time to choose anything, I just bought the first inexpensive wi-fi router. Since I like to break everything by nature, I almost immediately climbed into the Internet to look for ways to improve it.
But at that time, I found almost nothing but tips to drill holes in it. Yes, indeed, he often overheated and therefore worked unstable, but I did not go to such a risky step.
Fortunately, I sold it to my friend almost immediately.
When I needed such a device again, I already knew what functions I really needed, for me it was QoS. As an ordinary buyer, I began to look at the marketing descriptions of features and device chips. For me it seemed the only right thing then. It turned out not quite so.
I bought asus w520gu, I’m generally satisfied with it (more on that later), but I think it’s right to share my experience and information as I improved it.

New look at the choice of the router on the hardware characteristics

Buying a router, we pay a substantial part for the possibilities implemented by software. But the router is approximately like a computer, it has hardware, and there is a program.
So who's stopping us to choose the best iron, and then replace the program. It is almost a common thing even with computers, when the bundled system is removed and a new one is installed.
Of course, no one in the description writes hardware characteristics, here the Internet and vast communities of users will come to the rescue.
Surely there is more, but I liked the page - dd-wrt.com/wiki/index.php/Supported_Devices
There is a huge variety of devices, and for almost everyone the parameters are filled: Frequency (CPU frequency), RAM (RAM), Flash Memory (non-volatile memory), WLAN standard (supported Wi-fi standard).
Great now we see the hardware specifications and can choose, for the router as a small server almost all parameters are important, and it is also desirable to consider the support of usb ports, it will always come in handy.

Various unofficial firmware

Free firmware for many wireless routers based on BroadCom / Atheros / Xscale / PowerPC chips, originally developed for the Linksys series of routers, they are a miniature operating system based on the Linux kernel.
Briefly about known to me:

• DD-WRT dd-wrt.com
• Tomato www.polarcloud.com/tomato
• Openwrt openwrt.org
• Oleg firmware oleg.wl500g.info

I will not describe the system, to whom it is interesting to read it myself, a lot of diverse information (although most are in English)
To evaluate the possibilities of DD-WRT, look at demo dd-wrt.com/demo/index.asp
In short, people with a lot of experience in the linux world, and who have a few free nights, I advise you to try openwrt, you will be able to configure everything from scratch and put a lot of ported linux software.
Oleg is more focused on certain versions of routers, but provides a lot of useful features.
Most I advise you to pay attention to the first two firmware. They are very similar in features, some like one thing, others like another. Personally, I liked tomato to have an easy and convenient Ajax control interface.
')

Example with asus w520gu, what was and what became

Now I have asus w520gu and I am, in general, pleased with it. He stands somewhere 2500-3000 p and works out his money.
I wrote at the beginning that it is important for me to have QoS ( http://ru.wikipedia.org/wiki/QoS ). This is the prioritization of traffic, channel width, as well as the speed of response.
So that's how I was upset when I saw the implementation of QoS in the factory firmware of my asus. The new rules were not added, but the built-in ones were very general, such as the voip game and so on.
Also, this router has a usb port, but in the factory version, nothing is connected to it except for the printer.
What I got after the installation of unofficial firmware:

• Overall stability and speed
• Fully customizable Qos (Or rather, the separation of the channel width by different ports, protocols, network interfaces and even the size of the downloaded traffic, at least it is always useful to lower the priority of torrents)
• Increased restriction on the number of compounds (important for p2p)
• A working usb port for external devices (not just a printer)
• A large number of settings, new features, and a very informative interface, traffic graphics, resource load, etc.
• And also, which is important, the linux platform, for which a lot of software is ported. With this, the possibilities are endless.
  For example, if you have a connected hard drive or a large flash drive, you can hang a simple http server, a torrent with a web interface, as well as make a file server on a router. In general, a home server can be made from a router.

Exemption from liability.

I want to warn in advance, to install unofficial firmware will require some knowledge. If you are not sure that you will master it yourself, then do not do it better, ask a friend Linuxuid or administrator.
Also, most likely it will violate the warranty agreement, so with the new firmware you can forget about the warranty.
If you follow the installation instructions clearly, you are unlikely to break something, most routers have a special boot mode, usually within the first 5 seconds the router waits for commands to restore and you can always reinstall everything again.
Most importantly, whatever you do, do at YOUR OWN RISK. I will not be responsible for the harm done to your router.

This is my first post here, so I’ll review all the objective comments and suggestions, you need to learn from your mistakes.