From: Scott Morris (swm@emanon.com)
Date: Thu May 12 2005 - 17:21:06 GMT-3
Well... That will certainly depend on the SP architecture!
More likely is't CPE-T1 --> Smartjack --> HDSL --> SLIK --> Fiber -->
MUX/other aggregating device
But it's one of the many potential scenarios depending on how new or how old
the physical design is!
Scott
-----Original Message-----
From: Anthony Pace [mailto:anthonypace@fastmail.fm]
Sent: Thursday, May 12, 2005 4:17 PM
To: swm@emanon.com; 'Hogo, Trust'; 'Group Study'
Subject: RE: T1 delievered on 2 wires or 4???
Is the conversion circitry actually in the smartjack itself on a chip?
Does that mean that there is no clunky looking NIU cards (or whatever they
are called)in old fashioned looking slots in the basement of that building
anymore?
So its:
CpeT1Device=>SmartjackSpittingOutDslOn1pair=>SinglePairWithNoRepeaters=>Dsla
mAtCentralOffice
Sounds like this is to maintain backwards compatitlity with the CPE device.
Anthony Pace
On Thu, 12 May 2005 15:58:39 -0400, "Scott Morris" <swm@emanon.com>
said:
> Actually, it boils down more to the oversubscription model used by
> service providers. People who have T-1's (synchronous and/or
> point-to-point
> interfaces) get really pissy when the bandwidth they paid for isn't
> available at random intervals.
>
> ADSL catered more to the way that traffic patterns exist at a consumer
> level and allowed service providers to work within the statistical
> probability of usage/bursty traffic. And the expectation was
> delivered to customers as that of an "availble, but not always usable"
> bandwidth. T-1 never worked that way.
>
> All traffic COULD still be muxed. Just depends on your engineering!
> (and
> your market expectations!)
>
> Scott
>
> -----Original Message-----
> From: Anthony Pace [mailto:anthonypace@fastmail.fm]
> Sent: Thursday, May 12, 2005 3:46 PM
> To: swm@emanon.com; 'Hogo, Trust'; 'Group Study'
> Subject: RE: T1 delievered on 2 wires or 4???
>
> 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:
> > > http://www.groupstudy.com/list/CCIELab.html
> > >
> > > __________________________________________________________________
> > > __ __ _ Subscription information may be found at:
> > > http://www.groupstudy.com/list/CCIELab.html
> > >
> > --
> > Anthony Pace
> > anthonypace@fastmail.fm
> >
> --
> Anthony Pace
> anthonypace@fastmail.fm
>
-- Anthony Pace anthonypace@fastmail.fm
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