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]

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
talk 517 tcp like tenex link, but across machine - unfortunately, doesn't use link protocol (this is actually just a rendezvous port from which a tcp connection is established)
talk 517 udp like tenex link, but across machine - unfortunately, doesn't use link protocol (this is actually just a rendezvous port from which a tcp connection is established)
vpac 1517 tcp Virtual Places Audio control
vpac 1517 udp Virtual Places Audio control
call-sig-trans 2517 tcp H.323 Annex E Call Control Signalling Transport [ITU-T] [ITU-T_TSB] 2013-01-31
call-sig-trans 2517 udp H.323 Annex E Call Control Signalling Transport [ITU-T] [ITU-T_TSB] 2013-01-31
802-11-iapp 3517 tcp IEEE 802.11 WLANs WG IAPP [Stuart_J_Kerry] [Stuart_J_Kerry] 2002-05
802-11-iapp 3517 udp IEEE 802.11 WLANs WG IAPP [Stuart_J_Kerry] [Stuart_J_Kerry] 2002-05
5169-5171 Unassigned
pcoip-mgmt 5172 tcp PC over IP Endpoint Management [HP_Inc_2] [Jeff_Jeansonne] 2014-04-28 2026-03-10
5172 udp Reserved
5173-5189 Unassigned
18517-18633 Unassigned

Contact Information

ID Name Organization Contact URI Last Updated
[HP_Inc_2] HP Inc. mailto:jeff.jeansonne&hp.com 2026-03-10
[ITU-T] ITU-T mailto:tsbsg16&itu.int 2013-01-31
[ITU-T_TSB] ITU-T TSB ITU-T mailto:tsbsg16&itu.int 2013-01-31
[Jeff_Jeansonne] Jeff Jeansonne mailto:jeff.jeansonne&hp.com 2026-03-10
[Stuart_J_Kerry] Stuart J. Kerry Chair IEEE 802.11 WG mailto:stuart&ok-brit.com 2002-05