From: James P Bowlin <jpbowlin@attmail.com> To: Jay R. Ashworth <jra@scfn.thpl.lib.fl.us> Cc: Brian Horvitz <horvitz@nsa.shore.net>; Ehud Gavron <GAVRON@ACES.COM>; Eric Wieling <eric@ccti.net>; nanog@merit.edu Subject: Re: Am I the bonehead or is it SprintLink? Date: Tuesday, September 16, 1997 8:49 AM

On Tue, Sep 16, 1997 at 01:17:03PM -0400, Brian Horvitz wrote:

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Could be that they physically handle full and partial T1 circuits on different facilities. I would imagine that Sprint brings in many circuits on a large trunk so, to avoid the interruption of moving one end of

On a full T1, whether it's terminating in a router or switch, the ckt will be engineered through a 3x1 dacs. This is just to move the ckt off the carrier DS3 and into the router or switch port. Subordinate slotting is not supported. The router or switch port would be a full T1 port. To downgrade the ckt to 256k the T1 must be muxed. A 1x0 or 3x0 dacs port must be inserted into the T1 path. The four DS0 channels would then be terminated on a channelized card, like a Cascade 9000 4-port T1 card. All of this can be pre engineered and a dacs xconnect completed at the time of cut over to activate the new configuration. Installing a new loop is a waist of everyone's time and the customers money. Maybe this is what Sprint had in mind. The customer would incur additional install charges and probably dual ckt payments for about a month. Todd ---------- the

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circuit which could take it down for hours while the telco does their work, they just install a new circuit and the customer does a cutover.

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It could, I suppose... but it's not too likely. I presume you mean that they terminate Full- and Frac-T services on different routers at their end? Maybe, but who cares? I've done this sort of thing on Frame circuits, and it runs just the way he expected: you put two people on the circuit on the phone, they both flip the same switched at the same time, and your throughput changes. If they'll _upgrade_ you from Frac- to Full- that way, why in hell won't they downgrade you?

Below is an excerpt from my direct reply to the original question.

It may be a little more complicated than you think. My first question is

whether you are currently paying for M24 functionality on the T1. M24 allows the carrier to break the T1 signal down to 24 DS0 signals. You cannot assume that this is the case for a full T1. If M24 is available (is the T1 terminated in the correct place on the carrier side) then your request is

fairly simple. If not, the T1 needs to be re-terminated in the correct place on the carrier side.

The reason that the upgrade is easier is that M24 functionality already exists for circuits less than T1 speeds. You CANNOT assume that M24 is on a circuit sold as a full T1 because there are additional costs incurred. One factor in designing T1s is whether M24 will be required because more equipment will be necessary.

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Is SprintLink being a bonehead or am I just totally clueless?

While I am not impartial regarding the participants, I do believe the sales droid should have expended more effort to understand what you wanted.

Jim Bowlin AT&T Network Operations

I have never nor will I likely ever speak for AT&T. These words are mine and only mine!