Internet Assigned Numbers Authority

Service Name and Transport Protocol Port Number Registry

Last Updated
2025-07-22
Expert(s)
TCP/UDP: Joe Touch; Eliot Lear, Kumiko Ono, Wes Eddy, Brian Trammell, 
Jana Iyengar, 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
48006-48047 Unassigned
48051-48127 Unassigned
48557-48618 Unassigned
mihcs MIH Command Services [RFC5679]
mihes MIH Event Services [RFC5679]
mihis MIH Information Services [RFC5679]
7ksonar tcp Teledyne Marine 7k Sonar Protocol [Teledyne_Marine] [Anders_Brandt_5] 2023-10-03 Defined TXT keys: None
7ksonar udp Teledyne Marine 7k Sonar Protocol [Teledyne_Marine] [Anders_Brandt_5] 2023-10-03 Defined TXT keys: None
brski-reg-cmp tcp Bootstrapping Remote Secure Key Infrastructure registrar with CMP capabilities according to the Lightweight CMP Profile (LCMPP) [RFC9483] [IESG] [IETF_Chair] 2024-09-23 [RFC9733] Defined TXT keys: None
caldav tcp Calendaring Extensions to WebDAV (CalDAV) - non-TLS [IESG] [IETF_Chair] 2012-02-17 [RFC6764] This is an extension of the http service. Defined TXT keys: path=<context path>
caldavs tcp Calendaring Extensions to WebDAV (CalDAV) - over TLS [IESG] [IETF_Chair] 2012-02-17 [RFC6764] This is an extension of the https service. Defined TXT keys: path=<context path>
core-rd tcp Resource Directory accessed using CoAP over TCP [IESG] [IETF_Chair] 2021-03-16 [RFC9176] Defined TXT keys: None
core-rd udp Resource Directory accessed using CoAP [IESG] [IETF_Chair] 2021-03-16 [RFC9176] Defined TXT keys: None
core-rd-tls tcp Resource Directory accessed using CoAP over TLS [IESG] [IETF_Chair] 2021-03-16 2022-04-14 [RFC9176] Defined TXT keys: None
core-rd-dtls udp Resource Directory accessed using CoAP over DTLS [IESG] [IETF_Chair] 2021-03-16 [RFC9176] Defined TXT keys: None
dccp-ping dccp ping/traceroute using DCCP [Samuel_Jero] [Samuel_Jero] 2012-11-14 1885957735 Defined TXT keys: None
dns-push-tls tcp DNS Push Notification Service Type [IESG] [IETF_Chair] 2019-11-25 [RFC8765, Section 6.1] Defined TXT Keys: None
dots-call-home tcp DOTS Signal Channel Call Home Protocol. The service name is used to construct the SRV service names "_dots-call-home._udp" and "_dots-call-home._tcp" for discovering Call Home DOTS clients used to establish DOTS signal channel call home. [IESG] [IETF_Chair] 2020-11-19 [RFC8973] Defined TXT keys: None
dots-call-home udp DOTS Signal Channel Call Home Protocol. The service name is used to construct the SRV service names "_dots-call-home._udp" and "_dots-call-home._tcp" for discovering Call Home DOTS clients used to establish DOTS signal channel call home. [IESG] [IETF_Chair] 2020-11-19 [RFC8973] Defined TXT keys: None
dots-data tcp DOTS Data Channel Protocol. The service name is used to construct the SRV service name "_dots-data._tcp" for discovering DOTS servers used to establish DOTS data channel. [IESG] [IETF_Chair] 2020-11-19 [RFC8973] Defined TXT keys: None
est tcp Enrollment Over Secure Transport [Jack_Visoky] [Jack_Visoky] 2017-10-06 [RFC7030]. Defined TXT keys: None
fix Financial Information Exchange (FIX) Protocol [Joakim_Johansson] [Joakim_Johansson] Defined TXT keys: Currently valid enumerated values: FIX Session Protocol Versions (SESSIONVERSION): 1.1 FIX Application Protocol Versions (APPLICATIONVERSION): 2.7, 3.0, 4.0, 4.1, 4.2, 4.3, 4.4, 5.0 Possible TXT records defined and their values (replace uppercase text with enumerations from the list above): txtvers=1 fix=APPLICATIONVERSION fix supported=APPLICATIONVERSION[,APPLICATIONVERSION, ... ,APPLICATIONVERSION] fixt=SESSIONVERSION
help HELP command [RFC1078] TCP Port Service Multiplexer (TCPMUX)
hpr-bldlnx HP Remote Build System for Linux-based Systems [Jeffrey_J_Walls] [Jeffrey_J_Walls] Defined TXT keys: rh73, rhel3, rhel4, deb31, suse102
hpr-toollnx HP Remote System that houses compilers and tools for Linux-based Systems [Jeffrey_J_Walls] [Jeffrey_J_Walls] Defined TXT keys: rh73, rhel3, rhel4, deb31, suse102
hpr-tstlnx HP Remote Test System for Linux-based Systems [Jeffrey_J_Walls] [Jeffrey_J_Walls] Defined TXT keys: rh73, rhel3, rhel4, deb31, suse102
jnx-kcsync tcp jollys keychain cloud sync protocol [Patrick_Stein] [Patrick_Stein] 2011-10-24 Defined TXT keys: hash=<40hex characters> salt=<40hex characters> uuid=<40hex characters> Example: hash=5e7580598c0d7064d4fc79faaeb42585e1a675f8 salt=f0164cb3a0c3d7efe75abea8fda86d2d56c8dda9 uuid=db61dc092922252e45bbb264f59147138c7fd5fa
msrps tcp MSRP protocol over TLS 2014-04-25 [RFC4976] Defined TXT keys:
presence Peer-to-peer messaging / Link-Local Messaging [XMPP_Registrar] [XMPP_Registrar] Defined TXT keys: See http://www.xmpp.org/registrar/linklocal.html Note: Registration updated May 2007. Was formerly listed as "iChat AV" (Apple's IM client for Mac OS X) with TXT keys: txtvers, port.p2pj, phsh, vc, 1st, AIM, msg, status, last When first shipped in Mac OS X 10.2, iChat's peer-to-peer messaging protocol was created to solve the problem of serverless messaging between peers on the same link. However, there is nothing inherent in the protocol that limits it to being only link-local; it was simply an artifact of iChat in Mac OS X 10.2 using link-local Multicast DNS to discover peers. With the advent of Wide-Area DNS-SD, it is also possible to use iChat's peer-to-peer messaging between machines on different links.
radiusdtls udp Authentication, Accounting, and Dynamic Authorization via the RADIUS protocol. This service name is used to construct the SRV service label "_radiusdtls" for discovery of RADIUS/DTLS servers. [IESG] [IETF_Chair] 2015-03-23 2015-10-06 [RFC7585] Defined TXT keys: None
radiustls tcp Authentication, Accounting, and Dynamic Authorization via the RADIUS protocol. This service name is used to construct the SRV service label "_radiustls" for discovery of RADIUS/TLS servers. [IESG] [IETF_Chair] 2015-03-23 2015-10-06 [RFC7585] Defined TXT keys: None
spx-hmp tcp SpinetiX HMP [SpinetiX_S_A] [Diego_Santa_Cruz] 2011-10-18 Defined TXT keys: txtvers=1 cport= the port for the content HTTP server (secondary HTTP server used for content publishing) mode= the mode in which the HMP device is currently operating, one of "normal", "safe" or "recovery" serial= serial number of the HMP device firmware= firmware version string (e.g., 2.1.0-0.1.7844) model= model string (e.g., HMP100)
sztp tcp This service name is used to construct the SRV service label "_sztp" for discovering SZTP bootstrap servers. [IESG] [IETF_Chair] 2019-01-17 [RFC8572] This protocol uses HTTPS as a substrate.
timezone tcp Time Zone Data Distribution Service - non-TLS [IESG] [IETF_Chair] 2015-08-03 [RFC7808] This is an extension of the http service. Defined TXT keys: path=<context path> (as per Section 6 of [RFC6763]).
timezones tcp Time Zone Data Distribution Service - over TLS [IESG] [IETF_Chair] 2015-08-03 [RFC7808] This is an extension of the https service. Defined TXT keys: path=<context path> (as per Section 6 of [RFC6763]).
wot tcp W3C WoT Thing Description or Directory [W3C_Web_of_Things_Working_Group] [Kazuyuki_Ashimura] 2022-11-22 2022-12-15

Defined TXT keys:

td: Absolute pathname of the Thing Description of the Thing or Thing Description of the Thing Description Directory.

type: Type of the Thing Description, i.e. "Thing" or "Directory". If omitted, the type is assumed to be Thing.

scheme: Scheme part of URL. One of the following values can be specified, with the standard registered URI interpretations [RFC7595]: http (HTTP over TCP),https (HTTP over TLS/TCP), coap+tcp (CoAP over TCP), or coaps+tcp (CoAP over TLS/TCP). If omitted, the scheme is assumed to be http.

wot udp W3C WoT Thing Description or Directory [W3C_Web_of_Things_Working_Group] [Kazuyuki_Ashimura] 2022-11-22 2022-12-15

Defined TXT keys:

td: Absolute pathname of the Thing Description of the Thing or Thing Description of the Thing Description Directory.

type: Type of the Thing Description, i.e. "Thing" or "Directory". If omitted, the type is assumed to be Thing.

scheme: Scheme part of URL. One of the following values can be specified, with the standard registered URI interpretations [RFC7595]: coap (CoAP over UDP), coaps CoAP over DTLS/UDP. If omitted, the scheme is assumed to be coap.

x510 tcp Security service to protocols [ITU-T_Study_Group_17] [Erik_Andersen] 2019-08-13 Defined TXT keys: None

Contact Information

ID Name Organization Contact URI Last Updated
[Anders_Brandt_5] Anders Brandt Teledyne Marine mailto:Anders.Brandt&Teledyne.com 2023-10-03
[Diego_Santa_Cruz] Diego Santa Cruz SpinetiX S.A. mailto:Diego.SantaCruz&spinetix.com 2011-10-18
[Erik_Andersen] Erik Andersen mailto:era&x500.eu 2019-08-13
[IESG] IESG mailto:iesg&ietf.org
[IETF_Chair] IETF Chair IETF mailto:chair&ietf.org
[ITU-T_Study_Group_17] ITU-T Study Group 17 mailto:era&x500.eu 2019-08-13
[Jack_Visoky] Jack Visoky mailto:jmvisoky&ra.rockwell.com 2017-10-06
[Jeffrey_J_Walls] Jeffrey J. Walls mailto:jeff.walls&hp.com
[Joakim_Johansson] Joakim Johansson mailto:joakim.johansson&tbricks.com
[Kazuyuki_Ashimura] Kazuyuki Ashimura mailto:ashimura&w3.org 2022-11-22
[Patrick_Stein] Patrick Stein mailto:Patrick.Stein&jinx.eu 2011-10-24
[Samuel_Jero] Samuel Jero mailto:sj323707&ohio.edu 2012-11-14
[SpinetiX_S_A] SpinetiX S.A. mailto:Diego.SantaCruz&spinetix.com 2011-10-18
[Teledyne_Marine] Teledyne Marine mailto:info&teledynemarine.com 2023-10-03
[W3C_Web_of_Things_Working_Group] W3C Web of Things Working Group mailto:team-wot&w3.org 2022-11-22
[XMPP_Registrar] XMPP Registrar mailto:registrar&xmpp.org