The IP Over NBMA (ION) Archive

[TG6124 <tg6124@topmail1.sbc.com>]

-----Original Message-----
From:	John T. Burgess, Jr. [SMTP:jtburgess@predictive.com]
Sent:	Tuesday, April 22, 1997 10:33 AM
To:	ion@nexen.com
Subject:	RE: RBOCs Reaching Limits

At 09:50 AM 4/22/97 +0200, you wrote:
>>xDSL  may not be a solution compatible with most of the RBOC's physical
>>cable plant. This may not change until the underlying infrastructure more
>>closely approaches the fiber-to-the-curb or fiber-to-the-house scenario. By
>>that time, however, other solutions will be more economical. 
>>
>>Tim Gorman
>False.  At least according to the ADSL Forum,
>70-80% of homes in the US are "within reach" of ADSL.
>This includes existing Digital Loop Carrier systems.
>This is why the TelCos are so interested in xDSL solutions!

>John

This may be so based on marketing claims. I have yet to see any xDSL units compatible with cable pairs having bridge tap and almost all unconditioned loops have bridge tap. This disqualifies a huge number of customers right off the bat or raises the installation costs to an extremely high level. Significant interference with other services can result from xDSL services in much of the outside plant unless methods are used to segregate the xDSL services. This raises the incremental cost of providing xDSL services thus affecting its underlying economics. I have yet to read about xDSL units designed to be integrated into telco mechanized loop maintenance systems although some may exist by now. Unless significant attention is paid to this, however, xDSL will not become a significant player anywhere because no one can afford manual checkout of loops as the first stage of the repair process and remain competitive.

70-80% of the homes being reachable is the same kind of hype that was applied to ISDN. Yes, the technology exists to do so. What is left out of the equation is the word "economically". The question is how many homes are reachable economically? I assure you, the telco's are not going to install T1 qualified loops, including line repeaters, into