Proposed Standard Socket Numbers
A proposal for assigning ARPANET socket numbers to standard services.
Postel, J., "Proposed Standard Socket Numbers", RFC 349, DOI 10.17487/RFC0349, May 1972, <https://www.rfc-editor.org/info/rfc349>.
@misc{rfc349,
series = {Request for Comments},
number = 349,
howpublished = {RFC 349},
publisher = {RFC Editor},
doi = {10.17487/RFC0349},
url = {https://www.rfc-editor.org/info/rfc349},
author = {J. Postel},
title = {{Proposed Standard Socket Numbers}},
pagetotal = 1,
year = 1972,
month = may,
} RFC text
Network Working Group Jon Postel
Request for Comments : 349 Computer Science
UCLA-NMC
NIC : 10428 30 May 72
Categories : Socket Numbers
References : RFC's 322, 204
Proposed Standard Socket Numbers
I propose that there be a czar (me ?) who hands out official socket
numbers for use by standard protocols. This czar should also keep track
of and publish a list of those socket numbers where host specific
services can be obtained. I further suggest that the initial allocation
be as follows:
Sockets Assignment
0-63 Network wide standard functions
64-127 Host specific functions
128-239 Reserved for future use
240-255 Any experimental function
and within the network wide standard functions the following particular
assignment be made:
Socket Assignment
1 Telnet
3 File Transfer
5 Remote Job Entry
7 Echo
9 Discard
these socket numbers (decimal) are to be used for the socket called "L"
in the official Initial Connection protocol (ICP) as specified in NIC
7104 the "Current Network Protocols" notebook.
[ 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 ]
ISO Plain Language
On this page
§1Coordinating Socket Numbers
Jon Postel proposes that a central administrator hand out official socket numbers for standard protocols. The administrator would also track and publish socket numbers where host-specific services could be found.
The memo relates these decimal socket numbers to the socket called L in the official Initial Connection Protocol.
The proposal gives one person responsibility for assigning service numbers and keeping a public list. That way, the numbers for standard services could be coordinated.
§1Proposed Ranges and Assignments
The proposed ranges are 0-63 for network-wide standard functions, 64-127 for host-specific functions, 128-239 reserved for future use, and 240-255 for experimental functions.
Initial proposed assignments within the network-wide range are socket 1 for Telnet, 3 for File Transfer, 5 for Remote Job Entry, 7 for Echo, and 9 for Discard.
The proposal divides socket numbers into four ranges. It assigns example numbers to five services, including Telnet, File Transfer, Echo, and Discard.
§3Proposal Status
RFC 349 presents a proposal: it says that an administrator should issue numbers and that the listed values are initial allocations. The unit metadata records RFC 433 as the later document that obsoleted it.
This memo proposes a system for assigning socket numbers. A later RFC replaced the proposal.