RFC 2840 (rfc2840) - Page 2 of 12
TELNET KERMIT OPTION
Alternative Format: Original Text Document
RFC 2840 TELNET KERMIT OPTION May 2000
1. MOTIVATION
The Kermit protocol [KER] performs error-corrected file transfer and
management over many types of connections, including terminal
connections, among diverse hardware and software platforms. It is
supported by a large number of Telnet clients and is also widely
available on the Internet hosts to which Telnet connections are made.
Traditionally, the Kermit protocol connection is started manually by
a user, or perhaps by an automated script. It is the user's
responsibility to start the Kermit server on one end of the
connection and the Kermit client on the other, or to start a Kermit
"send" operation on one end and a Kermit "receive" on the other.
This procedure grew out of necessity on ordinary direct-dial
connections, and serves its purpose within the limitations of that
context. But it introduces timing and dexterity problems, and lacks
an effective way for each Kermit program to determine the "mode" of
the other, or even its very presence, and therefore to know with
certainty which operations and procedures are legal on the connection
at any given time.
When Kermit services are offered on the Internet, however, a strong
coupling can be established between the two end applications by
having the Telnet protocol [TEL] serve as a supervisor for Kermit
sessions, ensuring that a valid and known relationship is always
obtained. Kermit sessions are, in effect, embedded within Telnet
sessions, with Telnet providing the mechanism for starting and
stopping them and defining which end is the Kermit client and which
is the Kermit server, possibly changing the relationship in response
to user actions.
2. DEFINITIONS
Kermit server
A software program that is ready to accept and act upon commands
in the form of well-defined Kermit packets [KER].
Kermit client
A software program that receives requests through its user
interface from a human agent (or a script or other source) and
translates them to command packets, which it sends to a Kermit
server, thus initiating a Kermit protocol transaction such as the
transfer of one or more files.
Altman & da Cruz Informational