Service Name and Transport Protocol Port Number Registry

Last Updated
2026-08-17
Expert(s)
TCP/UDP: Joe Touch; Eliot Lear, Kumiko Ono, Wes Eddy, Brian Trammell,
and Michael Scharf
SCTP: Michael Tuexen
DCCP: Eddie Kohler and Yoshifumi Nishida
Reference
[RFC6335]
Note
Service names and port numbers are used to distinguish between different
services that run over transport protocols such as TCP, UDP, DCCP, and
SCTP.

Service names are assigned on a first-come, first-served process, as
documented in [RFC6335].

Port numbers are assigned in various ways, based on three ranges: System
Ports (0-1023), User Ports (1024-49151), and the Dynamic and/or Private
Ports (49152-65535); the different uses of these ranges are described in
[RFC6335]. According to Section 8.1.2 of [RFC6335], System Ports are 
assigned by the "IETF Review" or "IESG Approval" procedures described in 
[RFC8126]. User Ports are assigned by IANA using the "IETF Review" process, 
the "IESG Approval" process, or the "Expert Review" process, as per 
[RFC6335]. Dynamic Ports are not assigned.

The registration procedures for service names and port numbers are
described in [RFC6335].

Assigned ports both System and User ports SHOULD NOT be used without
or prior to IANA registration.

************************************************************************
* PLEASE NOTE THE FOLLOWING:                                           *
*                                                                      *
* ASSIGNMENT OF A PORT NUMBER DOES NOT IN ANY WAY IMPLY AN             *
* ENDORSEMENT OF AN APPLICATION OR PRODUCT, AND THE FACT THAT NETWORK  *
* TRAFFIC IS FLOWING TO OR FROM A REGISTERED PORT DOES NOT MEAN THAT   *
* IT IS "GOOD" TRAFFIC, NOR THAT IT NECESSARILY CORRESPONDS TO THE     *
* ASSIGNED SERVICE. FIREWALL AND SYSTEM ADMINISTRATORS SHOULD          *
* CHOOSE HOW TO CONFIGURE THEIR SYSTEMS BASED ON THEIR KNOWLEDGE OF    *
* THE TRAFFIC IN QUESTION, NOT WHETHER THERE IS A PORT NUMBER          *
* REGISTERED OR NOT.                                                   *
************************************************************************

Request an Assignment
  [https://www.iana.org/protocols/apply]

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Service Name Port Number Transport Protocol Description Assignee Contact Registration Date Modification Date Reference Service Code Unauthorized Use Reported Assignment Notes
dc 2001 tcp
wizard 2001 udp curry
4501 Unassigned [IANA] [IANA] De-registered 08 June 2001
entextnetwk 12001 tcp IBM Enterprise Extender SNA COS Network Priority [Eugene_Cox] [Eugene_Cox]
entextnetwk 12001 udp IBM Enterprise Extender SNA COS Network Priority [Eugene_Cox] [Eugene_Cox]
20006-20011 Unassigned
20012 tcp Reserved
ss-idi-disc 20012 udp Samsung Interdevice Interaction discovery [Hong_Jungkih] [Hong_Jungkih]
ss-idi 20013 tcp Samsung Interdevice Interaction [Hong_Jungkih] [Hong_Jungkih]
20013 udp Reserved
opendeploy 20014 tcp OpenDeploy Listener [Todd_Scallan] [Todd_Scallan] 2005-08
opendeploy 20014 udp OpenDeploy Listener [Todd_Scallan] [Todd_Scallan] 2005-08
20015-20033 Unassigned
optocontrol 22001 tcp OptoControl [Kevin_Kuhns] [Kevin_Kuhns]
optocontrol 22001 udp OptoControl [Kevin_Kuhns] [Kevin_Kuhns]

Contact Information

ID Name Organization Contact URI Last Updated
[Eugene_Cox] Eugene Cox mailto:genecox&raleigh.ibm.com
[Hong_Jungkih] Hong, Jungkih mailto:jungkih.hong&samsung.com 2010-09-20
[IANA] IANA mailto:iana&iana.org
[Kevin_Kuhns] Kevin Kuhns mailto:kkuhns&opto22.com
[Todd_Scallan] Todd Scallan mailto:tscallan&interwoven.com 2005-08