nanog mailing list archives

RE: Verizon Policy Statement on Net Neutrality


From: "Naslund, Steve" <SNaslund () medline com>
Date: Fri, 27 Feb 2015 17:40:53 +0000

These standards are for the interoperability of the equipment between vendors.  There is no technical reason that you 
could not have one particular speed in one direction and any other speed in the opposite direction as long as you do 
not exceed the total bandwidth potential of the loop.  In fact, in the pre-standards days of DSL we could dial up any 
speed you wanted in either direction (because the DSLAM and CPE were from the same manufacturer).  In this case, the 
standard reflects what the customer wants, not a technical limitation.  If people want a different ratio of up to 
downlink speed it could certainly be done.  ADSL is by definition asymmetric.  We also sold SDSL which is symmetric 
service and the primary buyers were generally businesses.  See G.SHDSL  if you want a standard for symmetric DSL.  It's 
there, it is just not a popular.

Steven Naslund
Chicago IL


Jack,

I don't know what manufacturer you might be thinking of, but from a standards point of view ADSL2 and ADSL2+ both have 
faster upstream speeds than ADSL (G.dmt or T1.413)


 - ANSI T1.413 Issue 2 <http://en.wikipedia.org/wiki/ANSI_T1.413_Issue_2>,
 up to 8 Mbit/s and 1 Mbit/s
 - G.dmt <http://en.wikipedia.org/wiki/G.992.1>, ITU-T G.992.1, up to
 10 Mbit/s and 1 Mbit/s
 - G.lite <http://en.wikipedia.org/wiki/G.992.2>, ITU-T G.992.2, more
 noise and attenuation resistant than G.dmt, up to 1,536 kbit/s and
 512 kbit/s
 - Asymmetric digital subscriber line 2
 <http://en.wikipedia.org/wiki/Asymmetric_digital_subscriber_line_2> (ADSL2),
 ITU-T G.992.3, up to 12 Mbit/s and 3.5 Mbit/s
 - Asymmetric digital subscriber line 2 plus
 <http://en.wikipedia.org/wiki/Asymmetric_digital_subscriber_line_2_plus>
(ADSL2+),
 ITU-T G.992.5, up to 24 Mbit/s and 3.5 Mbit/s




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