So the list of equipment is a long and expensive one. There are two components that really stand out as overly expensive, firstly the access switch (2511) and then the frame relay switch (2522).
Both are actually fairly easy to find alternatives for. So lets look at the access switch first.
What we need from the access switch is a bunch of serial ports and a way to access them.
Luckily I found an old Barracuda web filter in the office that was out of support and unused. Although its got a custom OS and was password protected on the BIOS, this was easy to overcome, and really its just an MSI 1U machine. Ideal for a 32bit version of Ubuntu.
I loaded the live CD onto a USB drive, and once got round the BIOS limitation, loaded Ubuntu on it.
Its got a serial port already so connected this to the router.
I enabled ssh
sudo apt-get install openssh-server
and then installed minicom
sudo apt-get install minicom
Connecting with minicom
sudo minicom -s
I set the device (ttyS0) which I found through
dmesg | grep tty
and connected.
Great for a single connection, but as we are going to need a whole bunch of them we need a better solution. Thankfully this comes in for form of ser2net. Install this using
sudo apt-get install ser2net
and then have a look at the config file:
You should be able to see the ttyS0 connection already in there.
Now I can putty through to port 2000 and straight onto the router!
I will need to get a bunch of USB to serial converters, but these are only a couple of pounds on eBay, and a USB hub as its only got 4 USB ports (and maybe a quieter fan as its pretty noisy!). But all in all instead of £150-200 for a 2511 access server, its going to cost me about £20-30. Now I was lucky to not have to buy the server, but ANY linux machine can do the same thing!
We'll have a look at alternatives to the 2522 in a later post.