sundance-communications.com/forum Forums Other TDM Phone Systems 1A2 and Comkey Telephones & Systems Backboards

Hello again,

Would somebody please tell me what the different color backboards are for? I've seen blue, green, red, yellow, orange and purple. Some use 66 blocks others don't. Help!

I'm doing a new install and want to do it so you guys would be proud.

Thanks,
Dave

I Have seen Pink one's. It depends on how sexy the job is. Just like The lyrics of Right Said Fred.

Dave:

Blue: Station cable runs only;

Green: Incoming from CO (lines);

Purple: Circuits from PBX systems (trunks or stations);

Yellow: Misc. circuits such as intercoms or paging;

Red (Pink): 1A2 or key system line circuits;

Orange: Telco demarcation, such as RJ21X jacks;

White: Jumper wiring only.

Ed, I knew you would know the answers. When you say 1A2 or key system line circuits, do you mean the actual circuits leaving the KSU before they feed the stations (blue board)?

Thanks,
Dave

Ed or Bill maybe better at this question but here is what I have

Orange = Demark
Green = Network Connection
Purple = Common Equipment
Red = Key System
White = 1st level backbone
Gray = 2nd level backbone
Brown = Inter-building backbone
Blue = Horizontal
Yellow = Other

Yes the cable from the KSU the Red boards had the 25 pair multi pin blocks because of the way the stations were wired. I think in today's environment the Purple boards fit the needs.

Merritt:

Your information is TIA/EIA standards. This is their "authouritative" version of Bell System standards. They basically had to have their final say and two-cents worth. My answer was based upon Bell standards.

Red backboards represented 1A2 line circuits (there weren't issues with stations). There was a CO line in on the first pair of the line circuit; then the next three pairs represented the typical 1A2 line circuit (T1, R1, A, A1, LG and L). The fifth pair represented the common audible (ringing) output for that particular line. These could be "daisy chained" together if a company had multiple lines..

It's true, purple backboards are more appropriate these days since things aren't as "fixed" as they used to be. Ports are more "hybrid", so purple is the way to go for tails coming out of the switch.

What about the pink one's.

I have some pinks one's I'm not kidding. What where the pink one's used for? Government Jobs?

If they have the 25 pair blocks on them they are Red. I've see the red ones that looked pretty pink.

The sun must have faded them pink? That telephone closet must have had a sunny window? I don't think so. These are Pink. These are the special pink ones they installed in various IdF's . I bet they come from a political office.