[e2e] TCP, retransmissions, and ISPs with byte caps

[Cottrell, Les]

Not exactly what you want, but we have been monitoring (via ping) loss and RTT from SLAC to various homes (usually to the router/gateway at the home), in the San Francisco bay area, that have DSL or cable access for a couple of years. For example see:

http://www-iepm.slac.stanford.edu/cgi-wrap/pingtable.pl?dataset=hep&file=packet_loss&by=by-site&size=100&tick=monthly&from=SLAC&to=SF-ISP&ex=none

In the above table you can select other metrics or different "click ticks".  The names of the remote homes may give a clue to the provider (PBI=Pac Bell Internet), , SU = Stanford University acting as a front for Pac Bell DSL services.

For more on the general project see:

http://www-iepm.slac.stanford.edu/pinger/


> -----Original Message-----
> From: Philippe Strauss [mailto:philou at philou.ch] 
> Sent: Monday, June 17, 2002 9:54 AM
> To: end2end-interest at postel.org
> Subject: Re: [e2e] TCP, retransmissions, and ISPs with byte caps
> 
> 
> On Tue, Jun 18, 2002 at 12:10:41AM +1000, grenville armitage wrote:
> > 
> > On a different tangent, has anyone got pointers to
> > studies of TCP retransmission rates in the context of 'typical' 
> > consumer broadband access? (And, e.g., the (dis?)incentive 
> for a dodgy 
> > ISP to reduce packet loss rates if they're also counting 
> retransmitted 
> > packets against a customer's weekly/monthly usage cap.)
> 
> At TCP level, I dont'know.
> But i have a "smokeping" running on my home PC connected to
> the net thru CATV (terayon teracomm, not DOCSIS), you can take a look:
> 
http://philou.ch/cgi-bin/smokeping.cgi

It show packet loss rate on long term average (several hours).

But, as an ex-CATV-based-ISP network admin, I can say that there is no incentive to let packet loss rate grow, except if your are struggled by the internet bandwidth fee toward your upstream, which used to be the case in '96 - '98 for the emerging broadband business but not anymore.

If you want to maximize customer traffic, reduce packet drop. Retransmit are nothing compared to a connection that works well.

-- 
Philippe Strauss
http://philou.ch/

L'indifférence est le plus grand risque de notre temps,
la forme civilisée de la cruauté.  -- Zenta Maurina
--