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UDP and TCP as the New Waist of the Internet Hourglass

Document Type Expired Internet-Draft (individual)
Author Jonathan Rosenberg
Last updated 2008-02-11
Stream (None)
Intended RFC status (None)
Expired & archived
Stream Stream state (No stream defined)
Consensus boilerplate Unknown
RFC Editor Note (None)
IESG IESG state Expired
Telechat date (None)
Responsible AD (None)
Send notices to (None)

This Internet-Draft is no longer active. A copy of the expired Internet-Draft is available in these formats:


One of the fundamental design principles of the Internet is that IP represents a common intermediate protocol layer, linking together a variety of link layer technologies underneath with a large number of applications on top. When drawn graphically, this can be show as an hourglass with IP in the middle. The preponderence of NATs and firewalls in the Internet has changed this reality, such that UDP and TCP are now the waist of the hourglass. This document discusses this change and describes its implications for protocol and application design.


Jonathan Rosenberg

(Note: The e-mail addresses provided for the authors of this Internet-Draft may no longer be valid.)