Transport Multiplexing Protocol (TMux) (RFC1692)
Original Publication Date: 1994-Aug-01
Included in the Prior Art Database: 2000-Sep-12
Internet Society Requests For Comment (RFCs)
P. Cameron: AUTHOR [+4]
One of the problems with the use of terminal servers is the large number of small packets they can generate. Frequently, most of these packets are destined for only one or two hosts. TMux is a protocol which allows multiple short transport segments, independent of application type, to be combined between a server and host pair.
Network Working Group P. Cameron
Request for Comments: 1692 Xylogics, International Ltd.
Category: Standards Track D. Crocker
Silicon Graphics, Inc.
Transport Multiplexing Protocol (TMux)
Status of this Memo
This document specifies an Internet standards track protocol for the
Internet community, and requests discussion and suggestions for
improvements. Please refer to the current edition of the "Internet
Official Protocol Standards" (STD 1) for the standardization state
and status of this protocol. Distribution of this memo is unlimited.
One of the problems with the use of terminal servers is the large
number of small packets they can generate. Frequently, most of these
packets are destined for only one or two hosts. TMux is a protocol
which allows multiple short transport segments, independent of
application type, to be combined between a server and host pair.
This specification is the result of the merger of two documents: the
original TMux proposal which was the result of several discussions
and related initiatives through IETF working groups; and IEN 90 
originally proposed by Danny Cohen and Jon Postel in May 1979.
The TMux protocol is intended to optimize the transmission of large
numbers of small data packets that are generated in situations where
many interactive Telnet and Rlogin sessions are connected to a few
hosts on the network. In these situations, TMux can improve both
network and host performance. TMux is not intended for multiplexing
long streams composed of large blocks of data that are typically
transmitted by such applications as FTP.
The TMux protocol may be applicable to other situations where small
packets are generated, but this was not considered in the design.
The use of the TMux protocol in any other situation may require some
When network designers consider which protocols generate the most
load, they naturally tend to consider protocols which transfer large
blocks of data (e.g., FTP, NFS). What is often not considered is the
load generated by Telnet and Rlogin because of the assumption that
users type slowly and the packets are very small. This is a grave
underestimation of the load on networks and hosts which have many
Telnet and Rlogin ports on multiple terminal servers.
The problem stems from the fact that the work a host must do to
process a 1-octet packet is...