The subject of Lines & Trunks came up in another thread and I thought I'd recount a tale from my past. (Seems to be all I've got left these days)
Once upon a time, (about 20 years ago) in a kingdom by the sea (NYC,)a handsome young man (grave exaggeration) was the Network Manager for one of America's largest banks.
The network consisted of 3 GTD-4600s all tied together with T-1s (originally the connections had been 4 Wire E&M, but they had been upgraded.) The DIDs had also been upgraded to T-1s but the OGTs (Outgoing Trunks)were still coming in on copper.
One day at the Network Hub, everyone who dialed "9" for an OGT got reorder tone. Needless to say our hero was somewhat distressed. And discomfitted. And was being screamed at by everyone who was anyone and by most people who were not.
Tests at the demarc with a butt set and a ground wire produce dial tone. Dialing 9 from the switch - no dial tone. Obviously something is wroong with the switch. Our hero is getting beat up pretty bad.
To make a long story a little shorter, excessive troubleshooting and evaluation of SMA (System Malfunction Analysis) reveal that the switch attempted to seize DT. After 375 ms of no DT, the switch gave up on tht trunk and tried the next one. After 375 ms of no DT on the second trunk, the switch returned reorder tone and printed out a SMA report (in easily readable and translatable hexadecimal format).
What was going on? According to the Bell System Red Book all ground start trunks must return DT within 250 ms. The GTE switch added another 125 ms to the timing to cover for foulups and then gave up. Hence, reorder tone.
What was wrong with the CO? Well, according to NY Telephone - nothing. What about the parameters for Trunks? Well, surprise! They felt the parameters didn't apply. Why not?
Because, while we ordered (Ground Start) Trunks, And the NY Tel Sales Department wrote the order for (Ground Start) Trunks, the Switch delivered
(Ground Start) Lines. Trunks have to deliver DT in 250 ms. Lines can deliver it whenever they feel like it. In this case about 1000 - 1500 ms. Which is why we would get DT on the demarc with a butt set and a ground wire but not on the switch.
So when is a Trunk not a Trunk? When it's a Line.
Why did we get Lines and not Trunks? Because it was too expensive to provide trunks (Blocking, traficing, CCS, Erlangs, etc. is the reason. If anybody cares, I'll start another thread on that stuff - it's a subject unto itself.)
Not only did we not get trunks, neither did anyone else in the entire City of NY! Everyone who ordered GSTs got GSLs!
I began to set up a class action law suit (my brother is an attourney). I had progressed quite a way in writing it up when I was called in to the office of the Bank's Senior Vice President for Telecommunications.
"Silverman", he said, "You will forthwith cease and desist with this lawsuit. If you continue, you will be out of a job. Immediately."
So I gave it up. Later I discovered that the Chairman of the Board of NY Tel sat on the Bank's Board of Directors.
Surprise!
To the best of my knowledge, at least in NYC, if you order an analog GST today , you will still get a connection to the Line side of the switch. A monumentally inferior connection.
So much for quality service.
And now we know when a Trunk is not a Trunk.
Sam
