From: Anthony Pace (anthonypace@fastmail.fm)
Date: Thu May 12 2005 - 16:46:12 GMT-3
Scott,
again, very good info in your post! I know that HDSL was born out of the
desire to deliever the equivolent of a T1 on 1 pair, and that then the
other tecnologies sparang up simutaneous to the TELCO laws changing
(thus DSL emerged as an alternative to serial point-to-point in that it
could be delievered by a CLEC renting 1 single loop from the ILEC)
I know that T1's are ferquently MUXED onto ATM and then transparently
delievered as to the CPE gear on either end as serail T1, but if it's
going to a last mile of something other than a T1 (ESF with all the
signalling bits and CRC and all the stuff backward compatible to 1962)
why not just sell and deliever the new and improved DSL (whatever
flavor) right into the CPE device (router in my case).
Is it just the idea of a T1= good and DSL=bad for marketing purposes? Or
is it just to be able to hand the customer what they want (T1) and then
finding the best technical approach (separate form the terminology being
used to sell it)
does that question make sense? probobly not.
Anthony Pace
On Thu, 12 May 2005 15:25:54 -0400, "Scott Morris" <swm@emanon.com>
said:
> Hehehe... Telco Voodoo Magic. :)
>
> It's just a way to transport bits. The design concepts behind ADSL
> (shared
> medium with varying xfer rates) are significantly different at the
> telco-side of things than designing for HDSL or VDSL. So the assumptions
> people have about DSL in general don't always apply.
>
> For the telcos, it's all about conserving wire pairs. Physical
> infrastructure is a pain in the butt to fix, upgrade and change out. So
> any
> reuse is great!
>
> Where can you learn more about it? Hmmmmm... Good question.
> www.protocols.com perhaps, or Newton's Telecom Dictionary. It's just
> part
> of my vast collection of useless knowledge from working in the field so
> long!
>
> HTH,
>
> Scott
>
> -----Original Message-----
> From: Anthony Pace [mailto:anthonypace@fastmail.fm]
> Sent: Thursday, May 12, 2005 3:11 PM
> To: swm@emanon.com; 'Hogo, Trust'; 'Group Study'
> Subject: RE: T1 delievered on 2 wires or 4???
>
> Scott,
>
> This is very good information. Where can I learn more about it?
>
> ok. So people have come to believe T1=good DSL=flakey and opted for the
> old
> tried and true 4 wires delieverd by the ILEC, with many repeaters along
> the
> path; rather than gamble on DLS delievered by the CLECS. BUT now the
> smartjack accepts the 4 wires comming from my router interface and
> converts
> it to DSL so that it can be transmitted on 2 wires - and then does the
> same
> conversion at the other end of the circuit (keeping the entire process
> transparent to me)
>
> Anthony Pace
>
>
>
>
> On Wed, 11 May 2005 18:30:40 -0400, "Scott Morris" <swm@emanon.com>
> said:
> > A T-1 is 2-pair or 4 wires.
> >
> > However, many of the smartjacks are now HDSL capable (or VDSL
> > depending on proximity to CO) and that is delivered over a single pair
> > or two wires.
> >
> > The smartjack is doing magical conversion between the two. ;)
> >
> > HTH,
> >
> > Scott
> >
> > -----Original Message-----
> > From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf
> > Of Hogo, Trust
> > Sent: Wednesday, May 11, 2005 6:05 PM
> > To: Anthony Pace; Group Study
> > Subject: RE: T1 delievered on 2 wires or 4???
> >
> > Hope this might help.
> >
> > http://www.cisco.com/warp/public/788/products/vwicmf_t1.html
> > http://www.cisco.com/warp/public/63/wic-1dsu-t1.html
> >
> > ------
> > HQ
> >
> >
> > -----Original Message-----
> > From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf
> > Of Anthony Pace
> > Sent: Wednesday, May 11, 2005 4:50 PM
> > To: Group Study
> > Subject: T1 delievered on 2 wires or 4???
> >
> > I recently terminated a T1 and ISDN PRI in a remote location and was
> > able to see that the TELCO had terminated the T1 using a single pair
> > and the PRI using a single pair from the 25 pair bundle coming into
> > the Data Center's smart jacks.
> >
> > I was always under the impression that from the CSU/DSU (in my case it
> > was built into the router) to the smartjack and subsequently the NI
> > card in the MPO was 4 wires. 1 pair TX and 1 pair RX.
> >
> > Maybe between the CSU/DSU and the NI card it's 2 wires and then 4 for
> > the distance to the CO? ??? I am confused because I always believed
> > that DSL was born out of the efforts of finding a single pair
> > alternative to
> > T1 technology.
> >
> > Should PRI and DS1 be 1 pair or 2?
> >
> > Anthony Pace CCIE 10349
> >
> > --
> > Anthony Pace
> > anthonypace@fastmail.fm
> >
> > ______________________________________________________________________
> > _ Subscription information may be found at:
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> >
> > ______________________________________________________________________
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> >
> --
> Anthony Pace
> anthonypace@fastmail.fm
>
-- Anthony Pace anthonypace@fastmail.fm
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