🚀 go-pugleaf

John Navas wrote:
> 

> 
> Again, this is only a concern on *asymmetric* links.  Saturation of the
> uplink on a *symmetric* path will not have an adverse effect on the
> downlink.
>

Huh? Why not?

All our differences (not that we NEED to agree) seem to hinge on this
point, so I'll focus here for now.

Assume I've got my own dedicated, 10Mbps, full-duplex link.  If I
saturate the
upstream with 10Mbps of one-way UDP traffic (a video stream let's say),
my downstream
throughput potential (for a TCP session) would be severely limited, no?

The returning ACKs are going to be impeded whether the bandwidth
potential on the link is assymetrical or not.

All that matters is whether the upstream is saturated or not??

> >Even though bandwidth between the DSLAM and aggregation router is
> >assymetric (e.g. 45Mbps full-duplex),
> 
> Typically *symmetric*.
My typo, sorry.
 

> Possible, but unlikely given typical usage patterns of far more download
> than upload.  But so what?  Saturating the upstream will not adversely
> affect the downstream on a *symmetric* link.
> 
> >For example, if 5% (175) of the ~4000 ADSL users aggregated into a DS3
> >ran active web servers (uploading at constant 256Kbps), you'd saturate
> >the upstream.
> 
> I'd say it's typically more like 2000-3000 subscribers per DS3, with
> uplink capped at 128 Kbps, so that it would take more like about 15%.
> But again, so what?

I don't know what others are doing, but Bellsouth ADSL is 256Kbps
upstream.
Oh, and BTW, EVERY single loop I've analyzed is capable of 256Kpbs,
REGARDLESS of
loop length.
 
> >I'm not saying that this is extremely likely, but I
> >believe the best way to quantify the probablility is to quantify:
> >upstream oversubscription rate
> 
> >I suspect that few considered the impacts of upstream saturation on ADSL
> >throughput...or ADSL downstream traffic saturating the reverse channel
> >of their T1 customers...hmmmmm.
> 
> I've not seen any real evidence of a significant problem in this area --
> have you?  
My DSL get's slow too...impossible to know why without having backbone
access.

> Regardless, the issue would be the same for cable as for
> ADSL.
Absolutely.

BTW: I'm NOT frustrated by this conversation...as always I appreciate
the engaging dialog.

lb. 
-------------------------
Lawrence Baldwin
Protocol Scientist
678-624-0924
http://www.mynetwatchman.com - I'm under attack, now what?