Hi folks,
I'm an I.T. guy who's trying hard to learn the telecom side of things, and I'm always confused when people refer to a "trunk" and also "supertrunk".

For example, our current data provider has a line item on our invoice titled "Supertrunk Channel Ter/DS1"

I think I get the DS1 phrase (that's Digital Service Level 1, i.e. a T-1 line, right?).

Can someone define the two terms - "trunk" and "supertrunk" for me and how they probably apply to my ISP?

Also, do you have any suggestions on how I might go about learning more about datacom - i.e., are there any good books on the topic, video tutorials, etc.?

Thank you!
Ed

Never heard the term here. It's got to be a term made up by that provider. My guess is that it is a dynamic T1.

It's been a long time, but I seem to recall one carrier pushing their T-1 trunks that were ESF (as opposed to AMI) as "Super Trunks".

There may also have been some talk of PRIs, as opposed to standard T-1s as "Super Trunks", but I think either way it was all just marketing-speak.

Sam

Sometimes the best approach is the direct approach. Ask them what they mean by the term, and ask them to show you a reference.

Same here term is not one I ever heard.

Maybe they are referring to bonding multi T-1"s.......

A "Supertrunk" is basically a T1 line that is not PRI. You get the full 24 channels. I run into them from time to time out here but they are usually older circuits.

They can be a real pain to configure because they are so configurable, especially when a system has defaulted. I've never had a provider able to tell me exactly how one should be setup. It's usually a crap shoot unfortunately.

What Styx1 said...old school T1 with 24 in and out channels. No caller ID. Alot were setup as E&M4 but AT&T switch interfaces in our area require the customer equipment to be programmed as DID trunks but would also allow outbound service on the channels. Haven't seen any in years since the acceptance of PRI formats. Blast from the past.

I've seen Supertrunk most referred to by AT&T, so it may be a marketing name coined by AT&T for their 24-channel T1. Like everyone has said, you don't see them too often. PRI is much more common now, and can deliver more features (like caller ID), as others have mentioned.

The chan term you reference how they describe each end of the circuit. If you look at your Customer Service Record, you'll see two addresses for the chan term, one at your site and the other at the central office (unless it's a point to point between your sites).

Justin

Here are a some terms and couple of factoids.

SF = Super Frame
ESF = Extended Super Frame
AMI = Alternate Mark Inversion
B8ZS = BiPolar with 8 Zero Substitution
PRI = Primary Rate Interface
ISDN = Intergrated Services Digital Network
E&M = Ear & Mouth

A PRI/ISDN T1 is provisioned as ESF/B8ZS. It can contain as many as 23 "B" (voice) channels and 1 "D" (data) channel.

A T1 that that features Loop Start, Ground Start or E&M can support up to 24 channels. If compression is applied on both ends of the circuit, the number of channels can be increased.

To me, a trunk usually refers to a single channel of service (and we can drill down further to hairsplit between a line and a trunk).

A Supertrunk is indeed carried over a DS1 facility. One of the key differences is that all lines will ID to the same BTN or LDN. In other words, whether you call out on the 7th channel or the 23rd channel, the called party will always receive the same telephone number.

That's what the "TER" thing refers to. Back in the day I don't think they called it a Supertrunk...but maybe they did. Anyway, it was always identified by a main telephone number followed by TER 1, TER 2, TER 3, etc. "TER" was short for TERMINATION point, or something like that.

So "213-555-1212 TER 5" referred to said circuit, fifth channel.

Trunk:


Super Trunk:

Your one sick cookie "test-ok"..........................LOL.
:rofl: :rofl:

I thought it was the part of a car that people work out of?

I see TER 1, TER 2, etc. associated with terminal hunt groups, where the outbound Caller ID is the same for all lines. These are delivered via standard POTS lines, not DS1.

The first line is the actual WTN, the terminal number starts after that. So TER 1 is really the second line. To report trouble on the fifth line, you need to reference TER 4.

And it helps if Term 5 is the same at both ends. After 10 years or so of cable damage, reroutes, replacements, etc, there are usually 2 or more mis-labeled! Been there, Seen that!

I think we're still missing a basic definition here...the OP asked to define both terms, Trunk and Supertrunk.

First, a trunk is a connection between two pieces of switching equipment, as opposed to a "Line" which is a connection between a switch and a piece of terminal equipment (telephone, RAN, answering device, etc.) A trunk can be digital or analog, copper or fiber.

The only times I have seen the term "Supertrunk" used, it has referred to a T1 (Not PRI) with AMI framing. I've seen them in AT&T literature, as well as in sales proposals from (now defunct, I think) US-LEC.

Thank you all...I appreciate your input!

Does anyone know how (short of going to work for a telco company) how I can self-study and learn more about the topic of telcom??? Are there any decent (and accurate) books on the subject???

Ed

You can start here. They've got a lot of telcom specific stuff.

https://www.teracomtraining.com

Pick up a current Edition of NEWTON's TELECOM DICTIONARY. I have the 14th edition and it is dated March 1998

My old edition defines "Supertrunk" A cable that carries several video channels between facilities of a cable television company. A trunk between the master and the hub headends in a hub CATV system

"TRUNK" A communication line between two switching systems. The term switching systems typically includes equipment in a central office (the telephone Company) and PBXs. A tie trunk connects PBXs. Central office trunks connect a PBX to the switching system at the central office.
Again my dictionary is dated 1998 so I'm sure the definitions may be a little different.

Sorry I got so caught up in"super trunk" that I missed the part about "trunk".

A LINE is a connection between two phones or a phone and a switching system. (Correction: there doesn't have to be a phone at the end- it could be a fax, a modem, a whatever)

A TRUNK is a connection between two switching systems. The physical circuit could be identical to a line or it could be completely different.

In the UK they used to say (might still do) "I need to place a Trunk Call", where we would say " I need to make a Long Distance Call", because a Local call goes right to another phone (only passing through the local CO), where an LD call goes to at least one and often more, COs.


A Super Trunk, I think we can all agree, is "marketing-speak" and may mean different things in different locales.


Sam