Service Name and Transport Protocol Port Number Registry

Last Updated
2026-09-07
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
gist 270 udp Q-mode encapsulation for GIST messages [RFC5971]
ptcnameservice 597 tcp PTC Name Service [Yuri_Machkasov] [Yuri_Machkasov]
ptcnameservice 597 udp PTC Name Service [Yuri_Machkasov] [Yuri_Machkasov]
orbplus-iiop 1597 tcp orbplus-iiop [Robert_A_Kukura] [Robert_A_Kukura]
orbplus-iiop 1597 udp orbplus-iiop [Robert_A_Kukura] [Robert_A_Kukura]
homesteadglory 2597 tcp Homestead Glory [John_Tokash] [John_Tokash]
homesteadglory 2597 udp Homestead Glory [John_Tokash] [John_Tokash]
a14 3597 tcp A14 (AN-to-SC/MM)
a14 3597 udp A14 (AN-to-SC/MM)
a21-an-1xbs 4597 tcp A21 (AN-1xBS) [David_Ott] [David_Ott] 2006-02
a21-an-1xbs 4597 udp A21 (AN-1xBS) [David_Ott] [David_Ott] 2006-02
ininmessaging 5597 tcp inin secure messaging [Mike_Gagle_2] [Mike_Gagle_2] 2006-05
ininmessaging 5597 udp inin secure messaging [Mike_Gagle_2] [Mike_Gagle_2] 2006-05
5970-5983 Unassigned
pd-admin 9597 tcp PD Administration [Duk_Loi] [Duk_Loi] 2005-11
pd-admin 9597 udp PD Administration [Duk_Loi] [Duk_Loi] 2005-11

Contact Information

ID Name Contact URI Last Updated
[David_Ott] David Ott mailto:dott&qualcomm.com 2010-10-15
[Duk_Loi] Duk Loi mailto:dloi&peerdirect.com 2005-11
[John_Tokash] John Tokash mailto:jtokash&homestead.com
[Mike_Gagle_2] Mike Gagle mailto:mikeg&inin.com 2006-05
[Robert_A_Kukura] Robert A. Kukura mailto:kukura&apollo.hp.com
[Yuri_Machkasov] Yuri Machkasov mailto:yuri&ptc.com