Bonded SDSL (was RE: ITU G.992.5 Annex M - ADSL2+M Questions)

Frank Bulk - frnkblk at
Tue Jan 5 21:37:56 UTC 2010

It's being done by Actelis, Hatteras, and Zhone.  More exactly SHDSL or
similar variants.  The market is being well-served.


-----Original Message-----
From: Michael Sokolov [mailto:msokolov at ivan.Harhan.ORG] 
Sent: Monday, January 04, 2010 9:40 PM
To: nanog at
Subject: Bonded SDSL (was RE: ITU G.992.5 Annex M - ADSL2+M Questions)

Frank Bulk - <frnkblk at> wrote:

> We offer it, but practically speaking we haven't gotten much higher than
> Mbps on the upstream.

Sorry that I'm coming into this thread late (I have just subscribed),
but since I see people discussing DSL with beefy upstream, I thought I
would be brave and ask: do you esteemed high-end network op folks think
that there may be anyone in the world who might be interested in bonded
SDSL or not?

I have spent the past 5 years of my life learning everything there is to
know about SDSL.  Don't ask me why, I don't really know the answer to
that question myself.  I won't waste the bandwidth of this elite list
with dirty details of just what I've done with SDSL over the past 5 y,
but I'll give a link to an open source project that contains the body of
SDSL knowledge amassed over those years:


To make the long story short, for most of those years I kept trudging on
my project, treating it as an ultra-weird hobby that no one else in the
world could possibly have any interest in.  That persisted until 2009
when my project got noticed by two fairly major North American DSL
network operators.  (Well, one very major and one semi-major, but I'll
spare the names.)  Both of those had contacted me via my Open SDSL
Connectivity Project expressing interest in SDSL bonding.  Both
companies were telling me how much interest they had in SDSL bonding,
how much it would help their business to be able to offer bonded SDSL
services at 3 or 6 Mbps, how many customers they would be able to sign
up for these services, etc.  But when I asked them to back their
verbally-expressed interest with the tiniest amount of money or even no
money at all but a letter of intent which I could show to SBA etc, they
both went silent.  We've been playing a game of cat-and-mouse ever since.

As far as I could understand the existing situation is that the SDSL
infrastructure already deployed en masse by the major North American DSL
network operators already has the capability to serve out bonded SDSL
circuits, bonding either in the DSLAM or somewhere upstream of it, using
MLPPP, Multilink Frame Relay or whatever else one can think of, but the
problem is with CPE.  Apparently bonding-capable multiport SDSL CPE
devices are quite scarce.

Considering everything I've done with SDSL over the past 5 y, I believe
I have a right to say with confidence that I am more than capable of
designing and building a bonding-capable multiport SDSL CPE device for
any existing SDSL flavor with any desired number of ports (2, 4 or
whatever).  But what I don't know, and what I'm asking this highly
esteemed list for advice with, is this question: is there anyone at all
in the world who might have a real serious interest in such a thing?

If there is someone in the world who would truly appreciate having a
bonded SDSL solution, I would be delighted to work on developing such a
thing.  I would see it as a service to humanity whereby more use would
be made out of existing copper infrastructure in the ground instead of
having to dig more ditches to bury more fiber or whatever.  But if there
is no one in the world who would be interested in bonded SDSL (or at
least interested enough to invest one dime into development), then why


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