DIY

Getting Technical

DIY routers overcome the support limitations of commercial units, although until recently this has been at a cost of:

• acreage
• wattage
• additional terminology

Most DIY units have been based on superceded PC

• new mainboards now affordable - see below under "Hardware"

Additional hardware will be required, whatever main board is used:

• additional network cards
  • most USB-Ethernet devices supported
  • some USB modems will work in lieu one Ethernet card
• modem (if not provided by ISP as modem or Set Top Box)
• ethernet switch (unless only one computer will be accessing the Internet)
• WiFi Access Point
  • if required
  • might be implemented as a PCI/PCIe WiFi card in the routing PC

Hardware

Minimum suggested specs are approximately

• CPU - any X86 compatible of 333 Mhz or faster
  • ARM CPU may now be viable in lieu x86 compatible see "Strictly for Geeks" below
• RAM - 256 MB
  • additional functions, particularly caching, require extra RAM
• storage - 2 GB
  • effective caching requires several GB more disk space
• network interfaces
  • PCI, PCIe or USB-Ethernet required
  • 10 Mb/s suffice - unless running ADSL 2 or faster link
  • NB - speed of other devices on the LAN is irrelevant, LAN performance depends on the ethernet switch deployed

Wattage for DIY has been somewhat higher than for commerical routers. A suitable objective, using 2010 or later componentry is 25 W. Lower wattage units are addressed under "Strictly for Geeks" below. CPU wattage is a poor indicator because other chips and peripherals consume somewhat more. Suggested basis for low wattage router:

1. HP Proliant Microserver
2. mainboards based on C50 CPU - which appears to have been used mainly in netbooks
3. mainboards based on E350 CPU
4. mainboards based on Atom CPU are something of an enigma
   • can be the lowest cost available but
   • wattage surprisingly high, because of associated chips
5. mainboards based on VIA CPU
   • expensive unless s/hand
   • not particularly low wattage
6. mainboards based on Pentium III CPU
   • reliability might be reduced because of age
   • zero cost & acceptable wattage

Software

Many Linux and BSD can be configured a gateway-router, but it is generally simpler and more watt efficient to use a specialised firewall/gateway distribution. Better known ones are listed in Linux_Distribution_Recommendations Although BSD based distributions such as Monowall are quite functional, their use would involve an additional learning curve for most people

Zoning

Software for DIY routers implements similar network zoning to that in commercial routers. An aspect that is different is the colour coding of zones:

• RED for untrusted/unfiltered Internet
• GREEN for most trusted, wired LAN connections
• BLUE for less trusted WiFi connections
• PURPLE for additional LAN zone
• ORANGE for Demilitarized Zone, (DMZ)
  • not required by most home users
  • typically used for stand-alone servers, to which access from the Internet is permitted

Strictly for Geeks

Be aware that the following techniques can render commecial routers unusable and perhaps unrecoverable, if applied unsuccessfully.

openWRT

openWRT http://wiki.openwrt.org is a long standing project aimed initially at utilising improved software on commerical routers. More recently it has morphed to:

• a more general embedded Linux distribution for compact devices
• covering a much wider range of off-the-shelf devices

One of the more popular devices to which openWRT it is currently applied is the TP-Link TL-703N

• not sold on the Australian market
• must be sourced from China
• nearest equivalent on the Australian market appears to be the TP-Link TL-MR3020

Developer Boards

DIY routers based on bare boards utilising an ARM CPU have become viable during 2012.

• have potential to match commerical routers in wattage and acreage
  • whilst maintaining advantage of frequent software updates
• require more careful matching of hardware and software
  • ARM compilations are not as "portable" as x86 compilations
    • advisable to select hardware having an ARM CPU series matching the compilation
• raspberry pi is best known hardware example - see Raspberry Pi
  • IPFire is the only well-known firewall/router that has reached released level for it
  • alternatively, raspbian could be adapted as a firewall/router for it

Developer boards typically have more RAM & CPU resources than openWRT devices thus making print servers and caching routers more practical.

--Rpeters 15:34, 1 September 2013 (EST)