New televisions from China or Taiwan

Jul 25, 2010 102 Replies

Ah. Well we had (big) routers in several racks (800 wide, 1000 deep, 47u high) as well as optical kit. Each bit of kit had its routing engine (with two serial ports) as well as a backup engine, so each box needed 4 serial connections back to a terminal server as well as two ordinary ethernet connections back to a switch. All this was only manageable with

400x400 vertical cable management ducting and 24 or 48 cat5 ports prewired between racks. Then there were a couple of hundred fibres connecting the routers and the optical kit, running in different ducting on top of the racks. So, some huge optical patch panels too.

Well, this is why I'm not sure what I was trying to do was going to scale. The answer was to have them made up on site, which worked well enough for copper and power - I didn't even try that with fibre.

But doing that sort of thing was the only way to keep on top of the rats nest. Trouble is, there's always folks back home who seem to think that all cables are infinitely thin, and should therefore not pose a problem.

By the time I retired, we were just starting to look at precabling fibre connections between racks, too, but I don't know whether than got taken any further.

I hope all your cables are labelled at each end, then :-)

I try and avoid dealing with routers :-)

(serial? Is this old kit by any chance?)

I might consider doing that for a major routing install, but for network and power there's no way - nobody here's going to accept hiring a professional wireman for a day to install a single server.

Fortunately we don't suffer that :-)

In the newer stuff, yes. The older rats-nest, no :-( We keep talking about rewiring that rack completely...

Though there is some argument as to how they're labelled. I reckon both ends need both source and destination (source so you can plug it into the right hole again, destination so you can trace). Others think it merely needs labelling with the other end, so eg Server X NIC 2 is on the end which plugs into switch 2 port 34, and I think that's barking. Or am I just overly paranoid?

No, brand new. These ports are the connection method of last resort. Methods of reaching your kit:

1) in band SSH to the router (or workstation) 2) If the network's sufficiently buggered that you have to go out-of band, ISDN to the terminal server at the PoP, then ssh to the router over the PoP LAN. 3) If the PoP's ethernet switch is down as well, or the router is sufficiently buggered so it's not responding via ethernet, then on the terminal server reverse telnet to another port on the terminal server that's connected to the router console port at 9600bps 4) If the ISDN is not working, there is also a modem connection to the terminal server.

Either you label the cable with source and destination at each end, or you label generically and store the mapping in a database. If you don't put source and destination at each end, and a cable gets disconnected by accident, you then have to trace it through to the other end and then back again - what a waste of time! And you have to hope that the cabling is correct, so that the other end f the disconnected cable is in the far port it's supposed to be in!

We always did the latter, as there were unfortunately always going to be lots of klods potentially messing with the cabling. So each end of any cable had the same label and you looked that cable up in the database to see what it was connected to. If you have an e-mail address there's a doc I can send you.

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