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The New Waist of the Hourglass

Document Type Expired Internet-Draft (individual)
Expired & archived
Author Hannes Tschofenig
Last updated 2013-01-10 (Latest revision 2012-07-09)
RFC stream (None)
Intended RFC status (None)
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This Internet-Draft is no longer active.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:


When developing a new application layer protocol the question about its foundation arises. The decision will be impacted by various factors but the ability for the solution to be deployable in today's Internet will certainly play a big role since various intermediaries may lead to a brittle communication architecture. The waist of the hourglass has changed over time: new applications have to run on top of UDP or TCP. Protocol designs that use other transport protocols have turned out to be undeployable on the public Internet. Running protocols on bare IP is also doomed to fail. This change is not theoretic in nature but has real-world implications for protocol designers. There is also a trend to run applications on top of HTTP/HTTPS. The author seeks more input from the wider IETF community about the deployment situation of protocol filtering by intermediaries and on the impact for protocol designers. This document is being discussed at


Hannes Tschofenig

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