[lug] DSL in Denver?

Chris M chrism at peakpeak.com
Tue Feb 1 21:41:17 MST 2000


>On Thu, Jan 27, 2000 at 09:28:06AM -0700, Viggy wrote:
>  > Are you in an apartment?  Is this a fairly new housing complex?  There
>  > are a couple of reasons why you cannot get DSL (or ADSL):
>  >
>  > 1)  You have to be within 15,000 feet of the CO (phone switch).  This is
>  > 15,000 feet of wire, not 15,000 driving, or line of sight.
>  > 2)  Some of the "older" new housing complexes was wired with fiber
>  > optical cable to support all of the houses, and any "upgrades" (i.e. a
>  > resident orders two more phone lines, etc.).  Fiber is not compatible
>  > with ADSL.
>  > 3)  If this is an apartment complex, and old enough, the phone lines
>  > might be multiplexed.  In other words, USWest puts more than one phone
>  > number on a physical pair that leads into the apartment building.  ADSL
>  > is not compatible with this setup.
>
>There's some truth to this and some half-truths.
>
>For #1: Not true with some flavors of RADSL and SDSL.  Limits have been
>pushed further than 15,000 feet.  Usually the available speed drops the
>further you get from the head-end equipment.
>
>USWest is sticking with the lower numbers for standardization and since
>they have a huge investment in the equipment they originally went with.


These are not the only reasons.  There is dialtone service quality 
(tariffed stuff) to worry about.  They can't just stick anything on 
the copper, the voice quality still has to be there.  So the length 
is lower so that they can maintain that quality.

>Some of the competitors like Rhythms, JATO, FlowPoint, and Covad have better
>equipment and if they have a POP (point-of-presence) in the Central Office
>that services your area, you can usually get service further out than USWest
>offers.


And they are not as closely regulated by the PUC like US West is.

>
>Example: USWest says I'm not in service coverage.  My Rhythms connection
>was expected to run about 512K max (RADSL), and actually tested to a max
>speed of 784 symmetric (same up as down) during the installation.  (And
>hoo boy, I tell ya, I was SORELY tempted to put in the order to just
>LEAVE it that fast after seeing that here at home... whew!)
>
>For #2: Also true to a point.  Fiber is typically used to feed systems
>that use "concentration" and are designed for voice service like GR-303
>equipment and SLC-96 compatible channel banks.  These play hell with
>standard analog modems, and because you don't have copper all the way to
>the CO, DSL cannot ride out to you.  HOWEVER, if the telco has a powered
>vault or other powered location with enough copper in a particular
>subdivision or (better yet) apartment/condo complex, they will typically
>install a head-end DSL box at the "end" of the fiber (most fiber is laid
>out in ring topology if it's SONET... doesn't have to be, but usually
>is...) and can service the neighborhood that way.  So it's usually a
>number-crunching/bean-counting exercise for the telco.  If they can
>recoup the cost of the extra equipment and LOTS of people in a
>particular area have shown an interest in DSL service, they *can* do it,
>it's just a matter of time and money.


But since there are entire cities that don't even have DSL yet, US 
West is not likely to pursue a cul-de-sac in one market for a handful 
of business.

Chris

>
>For #3: It's just an extension of the engineering dilemma the voice
>telco's put themselves in in #1.  Technologies like GR-303 and SLC-96
>allow a telco to have a much better use of their facilities with less
>copper in the ground, but they didn't anticipate someone coming up with
>a way to do broadband over copper (while still using that same pair for
>dial-tone voice) ten years ago.


>--
>Nate Duehr <nate at natetech.com>
>
>GPG Key fingerprint = DCAF 2B9D CC9B 96FA 7A6D AAF4 2D61 77C5 7ECE C1D2
>Public Key available upon request, or at wwwkeys.pgp.net and others.
>
>Content-Type: application/pgp-signature
>
>Attachment converted: Digit:Untitled 165 (????/----) (00035EE1)





More information about the LUG mailing list