[NCLUG] DSL Throttling or General Congestion?

[Michael Milligan]

Stephen Warren wrote:
> Michael Milligan wrote:
> 
> That (being Qwest's problem) doesn't sound likely.

Actually, I'm pretty darn sure the problem is at the RT (DSLAM) about a
mile from my house.  I bet dollars to donuts that the uplink is only
1.5Mb/s to the fiber, whether it is ATM or not is irrelevant (though I
know it is).  There are 25 houses in my neighborhood of which 10 or more
have 1.5Mbs DSL service already...  so, no matter how you slice it, you
can't stuff 10.5Mb of traffic onto one 1.5Mb/s ATM VC when everyone
tries to download music via P2P networks all at the same time (every
evening).  Cells have to be dropped.  Same goes for any ATM router in
the core...  if aggregate traffic exceeds capacity of in- or out-going
links, cells get dropped, end of story.  Which ones get dropped is
another (interesting) topic...  there's also queue sizes and introduced
queuing delays of cells when traffic levels approach saturation as
well...  I pretty darn sure I'm seeing the effects of both due to local
congestion.  And if I'm right, that will have little to do with which
ISP I'm using to take my IP packets.

Does anyone else think it's not a Qwest issue and switching ISPs would
help?  I'm game to go with FRII if it makes sense, they've been pretty
good to me w.r.t. co-lo service...  But from talking with a tech at
FRII, bascically all the Qwest DSL traffic is aggregated locally, routed
over the ATM cloud down to Denver (building on 16st Street), then
cross-connected to all the various ISPs that are available (most with
zero-mile DS3s or OC3s)...  so I doubt it would make any difference.

> With alternate ISPs, I *believe* that your phone line goes into an ATM
> switch at the nearest CO (central office), and that ATM line is then
> routed, in isolation, to the ISP. Only then does the ATM traffic get
> unpacked into potentially other transport technologies.

What's an "ATM line"?  Perhaps you are thinking of an ATM Virtual
Circuit (VC).

> The thing about ATM is that it's time division multiplexing, so there's
> an assigned fixed-bandwidth link all the way from your DSL modem at home
> all the way to the ISP.

You've got to be kidding.  That would be prohibitively expense for
Qwest.  If I had guaranteed bandwidth from my house to my ISP's
first-hop router, I'd probably need to be paying at least 5 times more
than I currently am.  Thought I WISH that were the case.

IMHO, if I'm right, Qwest needs to put a 6Meg card in my local RT soon
to alleviate this, or I'm switchin' to something else as soon as
something is available (can you say "WiMAX trial" anyone?).  It's so bad
that I'm even considering going back to CWX...

Regards,
Mike

-- 
Michael Milligan                                   -> milli at acmeps.com
Acme Professional Services LLC                        970-581-9948