Service Name and Transport Protocol Port Number Registry

Last Updated
2026-09-02
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]

Available Formats

CSV

XML

HTML

Plain text
Service Name Port Number Transport Protocol Description Assignee Contact Registration Date Modification Date Reference Service Code Unauthorized Use Reported Assignment Notes
smtp 25 tcp Simple Mail Transfer [IESG] [IETF_Chair] 2017-06-05 [RFC-ietf-emailcore-rfc5321bis-43]
smtp 25 udp Simple Mail Transfer [IESG] [IETF_Chair] 2017-06-05 [RFC-ietf-emailcore-rfc5321bis-43]
netnews 532 tcp readnews
netnews 532 udp readnews
ltp-deepspace 1113 tcp Licklider Transmission Protocol [RFC5326]
ltp-deepspace 1113 udp Licklider Transmission Protocol 2014-02-21 [RFC5326][RFC7122]
miroconnect 1532 tcp miroconnect [Michael_Fischer_2] [Michael_Fischer_2]
miroconnect 1532 udp miroconnect [Michael_Fischer_2] [Michael_Fischer_2]
ovtopmd 2532 tcp OVTOPMD [Eric_Pulsipher] [Eric_Pulsipher]
ovtopmd 2532 udp OVTOPMD [Eric_Pulsipher] [Eric_Pulsipher]
raven-rmp 3532 tcp Raven Remote Management Control
raven-rmp 3532 udp Raven Remote Management Control
bsfserver-zn 5320 tcp Webservices-based Zn interface of BSF [Bert_Paul] [Bert_Paul] 2008-05-01
5320 udp Reserved
bsfsvr-zn-ssl 5321 tcp Webservices-based Zn interface of BSF over SSL [Bert_Paul] [Bert_Paul] 2008-07-03
5321 udp Reserved
5322-5342 Unassigned

Contact Information

ID Name Organization Contact URI Last Updated
[Bert_Paul] Bert Paul mailto:bert.paul&apertio.com 2008-07-03
[Eric_Pulsipher] Eric Pulsipher mailto:eric_pulsipher&hp.com
[IESG] IESG mailto:iesg&ietf.org
[IETF_Chair] IETF Chair IETF mailto:chair&ietf.org
[Michael_Fischer_2] Michael Fischer tel:+49-531-21-13-0