RFC 1159 (rfc1159) - Page 1 of 2


Message Send Protocol



Alternative Format: Original Text Document



Network Working Group                                          R. Nelson
Request for Comments: 1159                           Clarkson University
                                                               June 1990


                         Message Send Protocol

Status of this Memo

   This RFC suggests an Experimental Protocol for the Internet
   community.  Hosts on the Internet that choose to implement a Message
   Send Protocol may experiment with this protocol.  Please refer to the
   current edition of the "IAB Official Protocol Standards" for the
   standardization state and status of this protocol.  Distribution of
   this memo is unlimited.

Discussion

   The Message Send Protocol is used to send a short message to a given
   user on a given terminal on a given host.  This is similar to the
   service provided by Unix's write command, which is limited to the
   users on that host.  This service is also known on some hosts as
   "SEND".

   As the Internet grows, more and more people are using hosts that do
   not run TCP/IP at all times.  These hosts may be able to use a simple
   protocol that can be implemented in a subset of TCP/IP.  The Message
   Send Protocol is one such protocol.

   Note that a message sending protocol is already defined using TCP.
   The SMTP protocol includes a "SEND" command that will direct mail to
   a user's terminal.  SMTP's SEND is not useful in this instance
   because TCP requires quite a bit of code.  For the purposes of
   standardization, we will include a TCP based Message Send Service.

TCP Based Message Send Service

   One message send service is defined as a connection based application
   on TCP.  A server listens for TCP connections on TCP port 18.  Once a
   connection is established a short message is sent by the client out
   the connection (and any data received by the client is thrown away).
   The client closes the connection after sending the message.

UDP Based Message Send Service

   Another message send service is defined as a datagram based
   application on UDP.  A server listens for UDP datagrams on UDP port
   18.  When a datagram is received by the server, an answering datagram



Nelson