Tom DeReggi wrote:

First off, in true technical theory, it is my opinion, that Latency =speed, Transfer rate = capacity. Latency is the "speed" in which one packet goes from point A to Point B. Transfer rate is the "quantity of packets" that can be transfered within a specific time. Therefore the Term "Speed" is incorrectly used in marketing.

While your usage is correct from the perspective of physics, the customer's perception of speed is the relevant one. I suspect most customers would say a service with 10Mbps and 30ms latency to a major backbone is "faster" than one with 1Mbps but 5ms latency to that same backbone.

(I'm assuming some value of "normal" here. Satellite-grade latency of, say, 2000ms, obviously skews customer perceptions. I don't know where I'd want to put the cutoff, but the exact numbers aren't as important here.)

As an aside, most of what I'm doing is purely speculatory from here on in. Anyone know whether any serious academic research has been done on this point?

Anyway, I don't want this to turn into anything related to semantics. Let's get back to the good stuff :)

MP4 Streaming Video-- only needs 400kbps.
VOIP --- only need MAX of 70kbps.
Web Browsing, VERY LITTLE, as most images are web optimized.

Haven't been to YouTube lately, I take it? :)

Between high-bandwidth services like that (and DailyMotion and Google Video and all the other folks doing the same sort of thing), and the dreaded peer-to-peer, and teleconferencing and maybe even telemedicine, and ...

My point is that while your numbers above may be sufficient for very casual users, today, those numbers won't hold much longer. I'm not sure they even hold today, honestly. Many residential customers want and expect more bulk bandwidth.

I just looked at's front page (to borrow one of your examples), and there's about sixty distinct images, plus the page's HTML, and other stuff like JavaScript and CSS imports. If you just cleared out your browser and DNS cache, and had to load that page completely from scratch, it's likely to take ten to fifteen seconds to load.

( offers a testing tool for that, but they're throwing in ridiculous latency numbers of 200ms per file, cumulative, and apparently never have heard of HTTP pipelining. I don't think I would take their numbers too seriously, but it's a good way to get basic "how big is a page" data to play with.)

The simple amount of bulk data there - amazon's home page including all those graphics adds up to around 300k, though it changes as the whole page is dynamic - is the key in this instance. Doesn't matter if you're plugged straight into with a crossover cable in this instance; the perception of slowness comes not from the latency but from the volume of data.

eBay's home page isn't much better, and's front page, including all scripts and images, is about 250 files and nearly 800K. (For comparison, on a classic 56k dialup, that's probably about three minutes just waiting for the front page to load.)

Sure if you are a IT guy -constantly downloading software drivers, or a Designer or Architec -constantly transfering CAD/Layout files, sure "Transfer Rate" is going to be important to you.

In all fairness, I should disclose my bias, it's been argued I'm an IT guy. :)

PS. I recognize next generation applications such as HD TV, can easilly justify GB transfer rates to the home. But we aren't in that generation today.

I think that generation is much, much closer than you think.

David Smith


** Join us at the WISPA Reception at 6:30 PM on October the 16th 2007 at ISPCON 
** ISPCON Fall 2007 - October 16-18 - San Jose, CA **
** FREE Exhibits and Events Pass available until August 31 **
** Use Customer Code WSEMF7 when you register online at **

WISPA Wants You! Join today!

WISPA Wireless List:



Reply via email to