atcomsystems.ca/forum Forums Wiring - Telecom Carriers - Trunks & Services T1's, CSU's and DSU's "Dry DSL"?

Had a service call to set up a construction office today. Two voice lines, a fax, and a "data" line, each with phone numbers assigned by Verizon.

Going off-hook on the "data" line (assuming DSL) circuit, all that I got was a "click/click" and then battery, indicative of a disconnected circuit in the 5ESS. When calling the number assigned to this circuit, I got what sounds like ring trip.

Since the customer didn't have their DSL modem on-site, all I could do is to verify that this click and battery was present at the jack.

Since I've never worked with the supposed "dry DSL" service that Verizon offers, should I be concerned about a callback? My guess is that they just use an un-programmed CO port to provide battery for the DSL transport to the premises. That seems like a pretty expensive means to do so.

Just askin...

Local at&t tech commented about a "dry DSL" the other day....and you have it all....

Also referred to as "naked DSL". If you hear anything you're lucky. I know some locations have started putting battery or dial tone with no LEN just so the phone company techs quit robbing the pairs because they think they are dead unused pairs. In this area you hear nothing, you either need a modem or DSL test set to see if there's anything on the pair. I'm guessing Ed that in your area this is their way of identifing it's a pair in use.

I don't see them a lot anymore, but used to...they often had a tag that said TXNU.

Really depends on how the network is set-up to deliver xDSL for a customer’s area on what else is hooked up on the pair with an “naked DSL service.” ... I’ve heard about every scenario you could imagine.

* LEN to DSLAM splitter just like a normal POTS + DSL service except the switch port is programmed for no inbound and outbound 911 only calls. (Just like if it had been disco-ed for no pay.)

* A combo card (LEN + DSLAM.) where the LEN can be programmed same as above.

* A combo card (LEN + DSLAM.) Where the LEN is set as a pseudo-LEN (a software marker of sorts) and the LEN is programmed to a null value, so as far as the actual switcher is concerned there’s no LEN there.

* I have never seen one used ‘round here, but I also understand there are DSLAMs (either modules of Next-Gen pair gain cards) that are set-up to supply battery too, so lines can be set up DSLAM to cable-pair specifically for naked DSL.

What you’re gonna get when connecting a tel-set or butt set to a dry DSL line and going off hook, is going to result in about anything you could image. :shrug:


That’s an ckt id for a CLEC leased broadband capable loop... Possible that “naked” or “dry” xDSL is being delivered on it but a LEC provided xDSL loop will not have a circuit id.

Our Verizon DSL is a dry loop.
1 no dial tone, just clicks
2 less expensive
3 works fine.