12 myths about how the Internet works

A list of assumptions we make when we hit the send button or download a video

Thirty years have passed since the Internet Protocol was first described in a series of technical documents written by early experimenters. Since then, countless engineers have created systems and applications that rely on IP as the communications link between people and their computers.

Here's the rub: IP has continued to evolve, but no one has been carefully documenting all of the changes.

"The IP model is not this static thing," explains Dave Thaler, a member of the Internet Architecture Board and a software architect for Microsoft. "It's something that has changed over the years, and it continues to change."

Thaler gave the plenary address Wednesday at a meeting of the Internet Engineering Task Force, the Internet's premier standards body. Thaler's talk was adapted from a document the IAB has drafted entitled "Evolution of the IP Model.'' 

"Since 1978, many applications and upper layer protocols have evolved around various assumptions that are not listed in one place, not necessarily well known, not thought about when making changes, and increasingly not even true," Thaler said. "The goal of the IAB's work is to collect the assumptions -- or increasingly myths -- in one place, to document to what extent they are true, and to provide some guidance to the community."

The following list of myths about how the Internet works is adapted from Thaler's talk

1. If I can reach you, you can reach me

Thaler dubs this myth, "reachability is symmetric," and says many Internet applications assume that if Host A can contact Host B, then the opposite must be true. Applications use this assumption when they have request-response or callback functions. This assumption isn't always true because middle-boxes such as network address translators (NAT) and firewalls get in the way of IP communications, and it doesn't always work with 802.11 wireless LANs or satellite links.

2. If I can reach you, and you can reach her, then I can reach her

Thaler calls this theory "reachability is transitive," and says it is applied when applications do referrals. Like the first myth, this assumption isn't always true today because of middle-boxes such as NATs and firewalls as well as with 802.11 wireless and satellite transmissions.

Join the Good Gear Guide newsletter!

Error: Please check your email address.

Tags wireless lan

Struggling for Christmas presents this year? Check out our Christmas Gift Guide for some top tech suggestions and more.

Keep up with the latest tech news, reviews and previews by subscribing to the Good Gear Guide newsletter.

Carolyn Duffy Marsan

Network World

Most Popular Reviews

Follow Us

Best Deals on GoodGearGuide

Shopping.com

Latest News Articles

Resources

GGG Evaluation Team

Kathy Cassidy

STYLISTIC Q702

First impression on unpacking the Q702 test unit was the solid feel and clean, minimalist styling.

Anthony Grifoni

STYLISTIC Q572

For work use, Microsoft Word and Excel programs pre-installed on the device are adequate for preparing short documents.

Steph Mundell

LIFEBOOK UH574

The Fujitsu LifeBook UH574 allowed for great mobility without being obnoxiously heavy or clunky. Its twelve hours of battery life did not disappoint.

Andrew Mitsi

STYLISTIC Q702

The screen was particularly good. It is bright and visible from most angles, however heat is an issue, particularly around the Windows button on the front, and on the back where the battery housing is located.

Simon Harriott

STYLISTIC Q702

My first impression after unboxing the Q702 is that it is a nice looking unit. Styling is somewhat minimalist but very effective. The tablet part, once detached, has a nice weight, and no buttons or switches are located in awkward or intrusive positions.

Latest Jobs

Shopping.com

Don’t have an account? Sign up here

Don't have an account? Sign up now

Forgot password?