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brookeKrige
join:2012-11-05
San Jose, CA

brookeKrige

Member

reasons for no VDSL2 fastpath?

If your noise margin is "good enough", then you're not pushing the limits of your copper lines, and fastpath should be technically feasible (i.e. sufficiently low error rates), right?

Especially if you qualify for a higher speed tier, one would think you'd be eligible for fastpath on every other lesser speed tier (requiring much reduced sync-rates). And therein perhaps lies the problem?:

ATT never wants a customer presented with a choice between: paying more for the higher speed tier at interleaved, versus staying on a cheaper tier because (in addition to the cost savings) it gives them fastpath?

There must be some kind of marketing idiom about such a policy: the fear of 'feature tradeoffs' cannibalizing your highest margin products?

Excepting the expected eventuality of vectoring, it might be a theoretical opportunity 'some day', similar in theme to the small speed bumps within tiers: they could open up fastpath for folks with the stats to support it, delivering a welcome small improvement. (If an RG were rooted, could it be used to enable fastpath, or still likely to be locked out via settings in the VRAD cards)?

rolande
Certifiable
MVM,
join:2002-05-24
Dallas, TX
ARRIS BGW210-700
Cisco Meraki MR42

rolande

MVM,

said by brookeKrige:

(If an RG were rooted, could it be used to enable fastpath, or still likely to be locked out via settings in the VRAD cards)?

I'm pretty certain that Fastpath is statically configured on the VRAD and negotiated by the RG. It is not enabled on the customer end.
CplEstesUSMC
join:2005-02-16
Douglasville, GA

CplEstesUSMC to brookeKrige

Member

to brookeKrige
I could be wrong but I was to understand that you could have different interleave values for different COS/diffserv values. I would imagine voice and video would be interleaved by 20ms or better while best effort data could be interleaved at something more competitive with Comcast, say .. 4ms down and 2ms up, plus serialization time would give you about 8ms to the first hop.

rolande
Certifiable
MVM,
join:2002-05-24
Dallas, TX
ARRIS BGW210-700
Cisco Meraki MR42

rolande

MVM,

said by CplEstesUSMC:

I could be wrong but I was to understand that you could have different interleave values for different COS/diffserv values.

That doesn't seem to be how AT&T implements it. They make it all or nothing on the port.
CplEstesUSMC
join:2005-02-16
Douglasville, GA

CplEstesUSMC

Member

said by rolande:

That doesn't seem to be how AT&T implements it.

Yeah I was just wondering if VDSL2 actually supports it or of it was just something I found in a forum. I was just trying to get someone else to google for me.

xsbell
join:2008-12-22
Canada

xsbell to CplEstesUSMC

Member

to CplEstesUSMC
said by CplEstesUSMC:

I could be wrong but I was to understand that you could have different interleave values for different COS/diffserv values. I would imagine voice and video would be interleaved by 20ms or better while best effort data could be interleaved at something more competitive with Comcast, say .. 4ms down and 2ms up, plus serialization time would give you about 8ms to the first hop.

You're not wrong, you can pretty much create as many different profiles as you wish, each with different settings, including the class of service. Up here all the shelves have "fastpath" profiles (INP=0, 0ms download and upload delay, etc.) but we also have a variety of interleaved profiles, some with an impulse noise protection value (INP) of 2, some 4, and even 6. Same with delays, some profiles have 6ms download delay and 4ms upload, some have 8ms download and 6ms upload. We also have different profiles for classes of service, ie., just internet, or internet with IPTV.
CplEstesUSMC
join:2005-02-16
Douglasville, GA

CplEstesUSMC

Member

Would you happen to know where find a good white paper in case I needed to argue this on a more formal level?

TestBoy
Premium Member
join:2009-10-13
Irmo, SC

TestBoy to brookeKrige

Premium Member

to brookeKrige
Reason.... they don't want to.
When I had one of their support argue with me that profiles were set in stone I gave up.

The hardware supports it. Just lazy.
cramer
Premium Member
join:2007-04-10
Raleigh, NC

cramer to rolande

Premium Member

to rolande
There is no fastpath within VDSL. Sure, engineers can tweak the various knobs, but it will always be interleaved. That's simply the way the technology is designed.