Service Name and Transport Protocol Port Number Registry

Last Updated
2026-10-09
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
[RFC 6335]
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 [RFC 6335].

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
[RFC 6335]. According to Section 8.1.2 of [RFC 6335], System Ports are 
assigned by the "IETF Review" or "IESG Approval" procedures described in 
[RFC 8126]. User Ports are assigned by IANA using the "IETF Review" process, 
the "IESG Approval" process, or the "Expert Review" process, as per 
[RFC 6335]. Dynamic Ports are not assigned.

The registration procedures for service names and port numbers are
described in [RFC 6335].

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
busboy 998 tcp
puparp 998 udp
x25-svc-port 1998 tcp cisco X.25 service (XOT)
x25-svc-port 1998 udp cisco X.25 service (XOT)
realsecure 2998 tcp Real Secure [Wes_Wilson] [Wes_Wilson]
realsecure 2998 udp Real Secure [Wes_Wilson] [Wes_Wilson]
dnx 3998 tcp Distributed Nagios Executor Service [John_Calcote] [John_Calcote] 2007-11-06
dnx 3998 udp Distributed Nagios Executor Service [John_Calcote] [John_Calcote] 2007-11-06
4992-4998 Unassigned
5995-5998 Unassigned
iatp-highpri 6998 tcp IATP-highPri [John_Murphy] [John_Murphy]
iatp-highpri 6998 udp IATP-highPri [John_Murphy] [John_Murphy]
7998 tcp Reserved
usicontentpush 7998 udp USI Content Push Service [Prakash_Iyer] [Prakash_Iyer] 2009-08-10
canto-roboflow 8998 tcp Canto RoboFlow Control [Canto] [Thomas_Schleu_2] 2014-02-26
8998 udp Reserved
9980 Unassigned
pumpkindb 9981 tcp Event sourcing database engine with a built-in programming language [Eventsourcing_Inc] [Yurii_Rashkovskii] 2017-04-18
9981 udp Reserved
9982-9985 Unassigned
kaostransport 9986 tcp KAOS secure message transport protocol for safety-critical environments [KAOS_Management_Group_LLC] [Philip_Duvalsaint] 2025-10-30
9986 udp Reserved
dsm-scm-target 9987 tcp DSM/SCM Target Interface [Mike_Dyslin] [Mike_Dyslin] 2006-08
dsm-scm-target 9987 udp DSM/SCM Target Interface [Mike_Dyslin] [Mike_Dyslin] 2006-08
nsesrvr 9988 tcp Software Essentials Secure HTTP server [Narayanan_Raju] [Narayanan_Raju] 2009-02-05
9988 udp Reserved
9989-9989 Unassigned
distinct32 9998 tcp Distinct32 [Anoop_Tewari] [Anoop_Tewari]
distinct32 9998 udp Distinct32 [Anoop_Tewari] [Anoop_Tewari]
wmedistribution 11998 sctp WorldMailExpress [Greg_Foutz] [Greg_Foutz] 2006-03
15998 tcp Reserved
2ping 15998 udp 2ping Bi-Directional Ping Service [Ryan_Finnie] [Ryan_Finnie] 2010-10-06
iec-104-sec 19998 tcp IEC 60870-5-104 process control - secure [Grant_Gilchrist] [Grant_Gilchrist] 2010-10-18
19998 udp Reserved
20811-20998 Unassigned
27877-27998 Unassigned
29170-29998 Unassigned
30940-30998 Unassigned
42511-42998 Unassigned
spremotetablet 46998 tcp Connection between a desktop computer or server and a signature tablet to capture handwritten signatures [SOFTPRO_GmbH] [Christoph_Hipp] 2012-07-19 2013-08-02
46998 udp Reserved

Contact Information

ID Name Organization Contact URI Last Updated
[Anoop_Tewari] Anoop Tewari mailto:anoop&next.distinct.com
[Canto] Canto mailto:tschleu&canto.com 2014-02-26
[Christoph_Hipp] Christoph Hipp SOFTPRO GmbH mailto:christoph.hipp&softpro.de 2013-08-02
[Eventsourcing_Inc] Eventsourcing, Inc. mailto:accounts&eventsourcing.com 2017-04-18
[Grant_Gilchrist] Grant Gilchrist mailto:grant&enernex.com 2010-10-18
[Greg_Foutz] Greg Foutz mailto:gregf&adminovation.com 2006-03
[John_Calcote] John Calcote mailto:jcalcote&users.sourceforge.net 2007-11-06
[John_Murphy] John Murphy mailto:john.m.murphy&mci.com
[KAOS_Management_Group_LLC] KAOS Management Group, LLC mailto:phil&GotKAOS.com 2025-10-30
[Mike_Dyslin] Mike Dyslin mailto:mike.dyslin&hp.com 2006-08
[Narayanan_Raju] Narayanan Raju mailto:narayanan.raju&hp.com 2009-02-05
[Philip_Duvalsaint] Philip Duvalsaint mailto:phil&GotKAOS.com 2025-10-30
[Prakash_Iyer] Prakash Iyer mailto:prakash.iyer&intel.com 2009-08-10
[Ryan_Finnie] Ryan Finnie mailto:ryan&finnie.org 2010-10-06
[SOFTPRO_GmbH] SOFTPRO GmbH mailto:christoph.hipp&softpro.de 2013-08-02
[Thomas_Schleu_2] Thomas Schleu Canto mailto:tschleu&canto.com 2014-02-26
[Wes_Wilson] Wes Wilson mailto:wwilson&iss.net 2003-10
[Yurii_Rashkovskii] Yurii Rashkovskii mailto:yrashk&eventsourcing.com 2017-04-18