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
prospero 191 tcp Prospero Directory Service [B_Clifford_Neuman] [B_Clifford_Neuman]
prospero 191 udp Prospero Directory Service [B_Clifford_Neuman] [B_Clifford_Neuman]
pana 716 udp PANA Messages [RFC5191]
gpfs 1191 tcp General Parallel File System [Dave_Craft] [Dave_Craft] 2004-11
gpfs 1191 udp General Parallel File System [Dave_Craft] [Dave_Craft] 2004-11
ultrabac 1910 tcp UltraBac Software communications port [Paul_Bunn] [Paul_Bunn]
ultrabac 1910 udp UltraBac Software communications port [Paul_Bunn] [Paul_Bunn]
mtp 1911 tcp Starlight Networks Multimedia Transport Protocol [Bruce_Lieberman] [Bruce_Lieberman]
mtp 1911 udp Starlight Networks Multimedia Transport Protocol [Bruce_Lieberman] [Bruce_Lieberman]
rhp-iibp 1912 tcp rhp-iibp [George_Nachman][Tom_Lake] [George_Nachman][Tom_Lake]
rhp-iibp 1912 udp rhp-iibp [George_Nachman][Tom_Lake] [George_Nachman][Tom_Lake]
armadp 1913 tcp armadp [Kevin_Welton] [Kevin_Welton]
armadp 1913 udp armadp [Kevin_Welton] [Kevin_Welton]
elm-momentum 1914 tcp Elm-Momentum [Willie_Wu] [Willie_Wu]
elm-momentum 1914 udp Elm-Momentum [Willie_Wu] [Willie_Wu]
facelink 1915 tcp FACELINK [J_H_Hermans] [J_H_Hermans]
facelink 1915 udp FACELINK [J_H_Hermans] [J_H_Hermans]
persona 1916 tcp Persoft Persona [Tom_Spidell] [Tom_Spidell]
persona 1916 udp Persoft Persona [Tom_Spidell] [Tom_Spidell]
noagent 1917 tcp nOAgent [Martin_Bestmann] [Martin_Bestmann]
noagent 1917 udp nOAgent [Martin_Bestmann] [Martin_Bestmann]
can-nds 1918 tcp IBM Tivole Directory Service - NDS
can-nds 1918 udp IBM Tivole Directory Service - NDS
can-dch 1919 tcp IBM Tivoli Directory Service - DCH
can-dch 1919 udp IBM Tivoli Directory Service - DCH
tvbus 2191 tcp TvBus Messaging [Brian_W_Beach] [Brian_W_Beach] 2003-01
tvbus 2191 udp TvBus Messaging [Brian_W_Beach] [Brian_W_Beach] 2003-01
csvr-sslproxy 3191 tcp ConServR SSL Proxy [Mikhail_Kruk] [Mikhail_Kruk]
csvr-sslproxy 3191 udp ConServR SSL Proxy [Mikhail_Kruk] [Mikhail_Kruk]
4191 tcp Reserved
dsmipv6 4191 udp Dual Stack MIPv6 NAT Traversal [RFC5555]
aol-1 5191 tcp AmericaOnline1 [Bruce_Mackey] [Bruce_Mackey]
aol-1 5191 udp AmericaOnline1 [Bruce_Mackey] [Bruce_Mackey]
limnerpressure 8191 tcp Limner Pressure [Aaron_Kleinsteiber] [Aaron_Kleinsteiber] 2014-01-16
8191 udp Reserved
sun-as-jpda 9191 tcp Sun AppSvr JPDA [Abhijit_Kumar] [Abhijit_Kumar] 2005-11
sun-as-jpda 9191 udp Sun AppSvr JPDA [Abhijit_Kumar] [Abhijit_Kumar] 2005-11
19021-19190 Unassigned
opsec-uaa 19191 tcp OPSEC UAA [Reuven_Harrison] [Reuven_Harrison]
opsec-uaa 19191 udp OPSEC UAA [Reuven_Harrison] [Reuven_Harrison]
19192-19193 Unassigned
ua-secureagent 19194 tcp UserAuthority SecureAgent [Reuven_Harrison_2] [Reuven_Harrison_2] 2003-01
ua-secureagent 19194 udp UserAuthority SecureAgent [Reuven_Harrison_2] [Reuven_Harrison_2] 2003-01
19195-19219 Unassigned
noit-transport 43191 tcp Reconnoiter Agent Data Transport [Theo_Schlossnagle] [Theo_Schlossnagle] 2009-05-19
43191 udp Reserved

Contact Information

ID Name Contact URI Last Updated
[Aaron_Kleinsteiber] Aaron Kleinsteiber mailto:protocol&limnerapp.com 2014-01-16
[Abhijit_Kumar] Abhijit Kumar mailto:as-iana-ports&sun.com 2005-11
[B_Clifford_Neuman] B. Clifford Neuman mailto:bcn&isi.edu 2022-02-18
[Brian_W_Beach] Brian W. Beach mailto:brian&tivo.com 2003-01
[Bruce_Lieberman] Bruce Lieberman mailto:brucel&iserver.starlight.com
[Bruce_Mackey] Bruce Mackey mailto:BAMackey&aol.com
[Dave_Craft] Dave Craft mailto:gpfs&ibm.com 2004-11
[George_Nachman] George Nachman
[J_H_Hermans] J.H. Hermans mailto:j.h.hermans&hiscom.nl
[Kevin_Welton] Kevin Welton mailto:Kevin.Welton&armltd.co.uk
[Martin_Bestmann] Martin Bestmann mailto:martin&datawatch.de
[Mikhail_Kruk] Mikhail Kruk mailto:mkruk&biscom.com
[Paul_Bunn] Paul Bunn mailto:iana&ultrabac.com
[Reuven_Harrison] Reuven Harrison mailto:rnd_ana&checkpoint.com
[Reuven_Harrison_2] Reuven Harrison mailto:rharrison&checkpoint.com 2003-01
[Theo_Schlossnagle] Theo Schlossnagle mailto:jesus&omniti.com 2009-05-19
[Tom_Lake] Tom Lake mailto:tlake&m-ware.com
[Tom_Spidell] Tom Spidell mailto:spidell&persoft.com
[Willie_Wu] Willie Wu mailto:willie&mds.com