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
ljk-login 472 tcp ljk-login [LJK] [LJK]
ljk-login 472 udp ljk-login [LJK] [LJK]
exp1 1021 tcp RFC3692-style Experiment 1 [IESG] [IETF_Chair] [1][RFC4727][RFC6335]
exp1 1021 udp RFC3692-style Experiment 1 [IESG] [IETF_Chair] [1][RFC4727][RFC6335]
exp1 1021 sctp RFC3692-style Experiment 1 [IESG] [IETF_Chair] [1][RFC4727][RFC6335]
exp1 1021 dccp RFC3692-style Experiment 1 [IESG] [IETF_Chair] [1][RFC4727][RFC6335]
exp2 1022 tcp RFC3692-style Experiment 2 [IESG] [IETF_Chair] [1][RFC4727][RFC6335]
exp2 1022 udp RFC3692-style Experiment 2 [IESG] [IETF_Chair] [1][RFC4727][RFC6335]
exp2 1022 sctp RFC3692-style Experiment 2 [IESG] [IETF_Chair] [1][RFC4727][RFC6335]
exp2 1022 dccp RFC3692-style Experiment 2 [IESG] [IETF_Chair] [1][RFC4727][RFC6335]
csdm 1472 tcp csdm [Robert_Stabl] [Robert_Stabl]
csdm 1472 udp csdm [Robert_Stabl] [Robert_Stabl]
c3 2472 tcp C3 [Eckhard_Grieger] [Eckhard_Grieger]
c3 2472 udp C3 [Eckhard_Grieger] [Eckhard_Grieger]
jaugsremotec-1 3472 tcp JAUGS N-G Remotec 1
jaugsremotec-1 3472 udp JAUGS N-G Remotec 1
4712-4724 Unassigned
truckstar 4725 tcp TruckStar Service [Brian_Toothill] [Brian_Toothill] 2010-10-15
truckstar 4725 udp TruckStar Service [Brian_Toothill] [Brian_Toothill] 2010-10-15
4726 tcp Reserved
a26-fap-fgw 4726 udp A26 (FAP-FGW) [David_Ott] [David_Ott] 2010-10-15
fcis 4727 tcp F-Link Client Information Service
fcis-disc 4727 udp F-Link Client Information Service Discovery [Makoto_Zukawa] [Makoto_Zukawa] 2010-10-15
capmux 4728 tcp CA Port Multiplexer [Nigel_Groves] [Nigel_Groves] 2006-06
capmux 4728 udp CA Port Multiplexer [Nigel_Groves] [Nigel_Groves] 2006-06
4729 tcp Reserved
gsmtap 4729 udp GSM Interface Tap [Harald_Welte] [Harald_Welte] 2009-01-16
apsolab-tag 5472 tcp The Apsolab company's dynamic tag protocol [Apsolab_Inc] [Jean-Francois_Gauthier] 2014-11-10
5472 udp Reserved
6472-6479 Unassigned
7472 Unassigned
otv 8472 tcp Overlay Transport Virtualization (OTV) [Dino_Farinacci] [Dino_Farinacci] 2008-01-07
otv 8472 udp Overlay Transport Virtualization (OTV) [Dino_Farinacci] [Dino_Farinacci] 2008-01-07
24681-24726 Unassigned
24727 Unassigned Unauthorized Use Known on port 24727
24728-24753 Unassigned
25472-25575 Unassigned
37472 tcp Reserved
37472 udp Reserved
3gpp-w1ap 37472 sctp W1 signalling transport [_3GPP_3] [Lionel_Morand] 2020-07-16
38472 tcp Reserved
38472 udp Reserved
f1-control 38472 sctp F1 Control Plane (3GPP) [Luis_Lopes] [Luis_Lopes] 2017-06-23

Contact Information

ID Name Organization Contact URI Last Updated
[_3GPP_3] 3GPP mailto:lionel.morand&orange.com 2020-07-16
[Apsolab_Inc] Apsolab Inc. mailto:admin&apsolab.com 2014-11-10
[Brian_Toothill] Brian Toothill mailto:brian.toothill&touchstar.co.uk 2010-10-15
[David_Ott] David Ott mailto:dott&qualcomm.com 2010-10-15
[Dino_Farinacci] Dino Farinacci mailto:dino&cisco.com 2008-08-21
[Eckhard_Grieger] Eckhard Grieger mailto:e.grieger&com-on.de
[Harald_Welte] Harald Welte mailto:laforge&gnumonks.org 2009-01-16
[IESG] IESG mailto:iesg&ietf.org
[IETF_Chair] IETF Chair IETF mailto:chair&ietf.org
[Jean-Francois_Gauthier] Jean-Francois Gauthier Apsolab Inc. mailto:jfgauthier&apsolab.com 2014-11-10
[LJK] LJK Software, Cambridge, Massachusetts mailto:support&ljk.com
[Lionel_Morand] Lionel Morand mailto:lionel.morand&orange.com 2020-07-16
[Luis_Lopes] Luis Lopes mailto:llopes&qti.qualcomm.com 2017-06-23
[Makoto_Zukawa] Makoto Zukawa mailto:zukawa&jp.fujitsu.com 2010-10-15
[Nigel_Groves] Nigel Groves mailto:nigel.groves&ca.com 2006-06
[Robert_Stabl] Robert Stabl mailto:stabl&informatik.uni-muenchen.de