Message Send Protocol 2
RFC 1312

Document Type RFC - Experimental (April 1992; No errata)
Obsoletes RFC 1159
Authors Russell Nelson  , Geoff Arnold
Last updated 2013-03-02
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Network Working Group                                          R. Nelson
Request for Comments: 1312                               Crynwr Software
Obsoletes: RFC 1159                                            G. Arnold
                                                  Sun Microsystems, Inc.
                                                              April 1992

                        Message Send Protocol 2

Status of this Memo

   This memo defines an Experimental Protocol for the Internet
   community.  Discussion and suggestions for improvement are requested.
   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.


   The Message Send Protocol is used to send a short message to a given
   user on a given terminal on a given host.  Unix's write command
   offers a limited form of this service through its host-local write
   command.  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 Internet protocols at all times.  These hosts may be able to
   use a simple protocol that can be implemented using UDP and 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 SMTP's SEND is not implemented by the majority of vendors at
   this time, and is difficult to use by unskilled users.  For the
   purposes of standardization, we will include a TCP based Message Send

Message Syntax

   The message consists of several parts, all of which must be present
   The first part is a single octet indicating the protocol revision,
   currently decimal 66, 'B'. The remaining parts are null-terminated
   sequences of eight-bit characters in the ISO 8859/1 alphabet. Some
   parts may be empty. All comparisons of parts (e.g., recipient,

Nelson & Arnold                                                 [Page 1]
RFC 1312                Message Send Protocol 2               April 1992

   cookie, etc.) are case-insensitive. The parts are as follows:

   RECIPIENT      The name of the user that the message is directed to.
                  If this part is empty, the message may be delivered to
                  any user of the destination system.

   RECIP-TERM     The name of the terminal to which the message is to be
                  delivered. The syntax and semantics of terminal names
                  are outside the scope of this specification. If this
                  part is empty, the "right" terminal is chosen. This is
                  a system-dependent function.  If this part consists of
                  the string "*", all terminals on the destination
                  system are implied.  If the RECIPIENT part is empty
                  but the RECIP-TERM is not, the message is written on
                  the specified terminal.  If both the RECIPIENT and
                  RECIP-TERM parts are empty, the message should be
                  written on the "console", which is defined as some
                  place where the message is most likely to be seen by a
                  human operator or administrator.

   MESSAGE        The actual message. The server need not preserve the
                  formatting and white-space content of the message if
                  this is necessary to display it.  New lines should be
                  represented using the usual Netascii CR + LF.
                  (Following the Internet tradition, a server should
                  probably be prepared to accept a message in which some
                  other end-of-line convention is followed, but a
                  conforming client must use CR + LF.)

                  The message text may only contain printable characters
                  from the ISO 8859/1 set, which is upward compatible
                  from USASCII, plus CR, LF and TAB. No other control
                  codes or escape sequences may be included: the client
                  should strip them from the message before it is
                  transmitted, and the server must check each incoming
                  message for illegal codes. (A server may choose to
                  display the message after stripping out such codes, or
                  may reject the entire message.) If the MESSAGE part is
                  empty, the message may be discarded by the server.

   SENDER         The username of the sender. (This and subsequent parts
                  were not present in version 1 of the Message Send
                  Protocol.) This part should not be empty. A server may
                  choose to accept, reject or ignore messages in which
                  the SENDER part is empty.
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