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RFC 347 UNKNOWN ARPANET · TESTING

Echo process

Hosts are invited to run a process that sends received data straight back, for debugging and measurement.

On rfc-editor.org ↗
PUBLISHED
May 1972
AUTHORS
J. Postel
STREAM
Legacy
SETUP
ICP per NIC 7104
HANDLING OF DATA
Echoed bit for bit
DOI
10.17487/RFC0347

RFC text

Original text · RFC Editor View on rfc-editor.org ↗ 
Network Working Group                           Jon Postel
Request for Comments : 347                      Computer Science
                                                UCLA-NMC
NIC  10426                                      30 May 72

Categories: Standard Processes


                                Echo Process


I suggest that for debugging and measurement purposes those hosts which
are willing implement an "Echo" process.
This echo process would listen for a request for connection and execute
the Initial Connection Protocol (ICP) as specified in NIC 7104 the
"Current Network Protocols" notebook.  Upon completion of the ICP the
echo process would wait for data from the network.  When the data is
received from the network it is echoed at once, (and the buffer space is
re-allocated).  By echoed I mean that the data received is sent back
over the network, bit for bit with no modification by the echo process.
The echo process is terminated by closing the network connections.
Note that BBN-TENEX has had such an echo process available for use for a
long time.







       [ This RFC was put into machine readable form for entry ]
       [ into the online RFC archives by BBN Corp. under the   ]
       [ direction of Alex McKenzie.                   12/96   ]

AI ELI5

On this page
PROBLEMHosts needed a simple service to help with debugging and measurement of the network.
MECHANISMA willing Host runs a Echo process that waits for a connection, performs the Initial Connection Protocol (ICP), then echoes back all data it receives.
WHY IT MATTERSThe proposal is voluntary: it applies to those hosts which are willing to implement it.

§1The Echo Process Proposal

Jon Postel suggests that, for debugging and measurement purposes, those hosts which are willing implement a Echo process. Participation is optional.

Some computers are asked to offer a simple test service, if they want to.

§2How the Echo Process Works

The process listens for a request for connection and executes the Initial Connection Protocol (ICP) as specified in NIC 7104, the "Current Network Protocols" notebook. After ICP completes, it waits for data from the network.

When data arrives it is echoed at once and the buffer space is re-allocated. Echoed means the data is sent back over the network, bit for bit, with no modification by the echo process. The process ends when the network connections are closed.

The computer waits for someone to knock, says hello the standard way, then sends back exactly what it gets.

§3Status

The RFC notes that BBN-TENEX has had such an echo process available for use for a long time. It is a short suggestion from Jon Postel at UCLA and sets no other requirements: any Host that is willing may implement the process, and no Host is required to.

It is just a friendly suggestion, not a rule.