Zephyr (protocol)

Zephyr was a part of the project Athena (1983-1991) and was at the Massachusetts Institute of Technology (MIT) as an instant messaging protocol and the associated application software package with strong Unix background developed. In keeping with the Unix philosophy "write computer programs so that they do only one task and do it well. " It was divided into several programs, which together form a complete system for exchanging messages.

Zephyr is today at some university environments such as at Carnegie Mellon University, Iowa State University, Stanford University, the University of Maryland, College Park, Brown University, North Carolina State University and at MIT used as before, even if it has been largely replaced by modern and more popular instant messaging systems like AIM and XMPP.

Zephyr sends UDP packets on ports 2102, 2103 and 2104. The protocol is incompatible with most routers in NAT mode because it passes only the internal IP address of the local network to the other party and thus the response data packets are not correctly can be routed. Zephyr uses only the Kerberos 4 protocol for authentication. It was made no more effort to implement support for Kerberos 5.