Internet Assigned Numbers Authority

Service Name and Transport Protocol Port Number Registry

Last Updated
2025-08-15
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]

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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
robotraconteur 48653 udp Robot Raconteur transport [Wason_Technology_LLC] [John_Wason] 2014-01-27
48654-48999 Unassigned
inspider 49150 tcp InSpider System [AnRobot] [Zhang_Xinnan] 2017-11-06
49150 udp Reserved
49151 Reserved 2024-12-20 [RFC6335]
ip-x25 Internet Protocol on X.25 Networks
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
accessone Strix Systems 5S/AccessOne protocol [Scott_Herscher_2] [Scott_Herscher_2] Defined TXT keys: None
boardplus tcp board plus application transfer protocol [CX5_SOFTWARE] [Yohei_Yoshihara] 2013-02-04 Defined TXT keys: None
brski-proxy tcp The Bootstrapping Remote Secure Key Infrastructure Proxy [IESG] [IETF_Chair] 2020-04-29 [RFC8995] Defined TXT keys: None
brski-registrar tcp The Bootstrapping Remote Secure Key Infrastructure Registrar [IESG] [IETF_Chair] 2020-04-29 [RFC8995] Defined TXT keys: None
carddav tcp vCard Extensions to WebDAV (CardDAV) - non-TLS [IESG] [IETF_Chair] 2012-02-17 [RFC6352] This is an extension of the http service. Defined TXT keys: path=<context path>
carddavs tcp vCard Extensions to WebDAV (CardDAV) - over TLS [IESG] [IETF_Chair] 2012-02-17 [RFC6352] This is an extension of the https service. Defined TXT keys: path=<context path>
certificates tcp Server for S/MIME and PGP certificates [IESG] [John_Levine] 2016-07-26 [draft-bhjl-x509-srv-01] 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
dns-update tcp DNS Dynamic Update Service [Stuart_Cheshire] [Stuart_Cheshire] 2019-05-04 DNS Dynamic Update Service for a given domain may not necessarily be provided by the principal name servers as advertised by the domain's "NS" records, and may not necessarily always be provided on port 53. The "_dns-update._udp.<domain>." SRV record gives the target host and port where DNS Dynamic Update Service is provided for the named domain.
dns-update udp DNS Dynamic Update Service [Stuart_Cheshire] [Stuart_Cheshire] 2019-05-04 DNS Dynamic Update Service for a given domain may not necessarily be provided by the principal name servers as advertised by the domain's "NS" records, and may not necessarily always be provided on port 53. The "_dns-update._udp.<domain>." SRV record gives the target host and port where DNS Dynamic Update Service is provided for the named domain.
dns-update-tls tcp DNS Dynamic Update Service over TLS [Stuart_Cheshire] [Stuart_Cheshire] 2019-05-04 [RFC6281] DNS Dynamic Update Service for a given domain may not necessarily be provided by the principal name servers as advertised by the domain's "NS" records, and may not necessarily always be provided on port 53. The "_dns-update._udp.<domain>." SRV record gives the target host and port where DNS Dynamic Update Service is provided for the named domain.
dnssd-srp tcp DNS-Based Service Discovery [IESG] [IETF_Chair] 2024-04-12 2024-09-05 [RFC9665] Defined TXT keys: None
dnssd-srp-tls tcp DNS-Based Service Discovery (TLS) [IESG] [IETF_Chair] 2024-04-12 2024-09-05 [RFC9665] 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
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
lobby Gobby [Gobby_0x539] [Gobby_0x539] Defined TXT keys: None
lontalk LonTalk over IP (ANSI 852) [Michael_Tennefoss] [Michael_Tennefoss] Defined TXT keys: None
lumiere tcp A protocol to remotely control DMX512 devices over the network [Gangsta_Ltd] [Jean-Charles_Boude] 2011-10-13 Defined TXT keys: None
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
robustirc tcp Like ircu (RFC1459), but failure tolerant due to strong consistency among n>=3 servers [Michael_Stapelberg] [Michael_Stapelberg] 2015-01-07 Defined TXT keys: None
smimeca tcp Domain signing certificate for S/MIME keys [IESG] [John_Levine] 2016-07-26 [draft-bhjl-x509-srv-01] Defined TXT keys: None
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.
tmsensor tcp Teledyne Marine Sensor [Teledyne_Marine] [Anders_Brandt_5] 2023-10-03 Defined TXT keys: None
tmsensor udp Teledyne Marine Sensor [Teledyne_Marine] [Anders_Brandt_5] 2023-10-03 Defined TXT keys: None
wdp tcp Windows Device Portal [Microsoft_Corporation_5] [Hirsch_Singhal] 2016-03-03 Defined TXT keys: D (device type), S (https port), A (architecture), T (tags)
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
[AnRobot] AnRobot mailto:webmaster&anrobot.org 2017-11-06
[CX5_SOFTWARE] CX5 SOFTWARE mailto:contact&cx5software.com 2013-02-04
[Erik_Andersen] Erik Andersen mailto:era&x500.eu 2019-08-13
[Gangsta_Ltd] Gangsta Ltd. mailto:jc&gangstamedia.com 2011-10-13
[Gobby_0x539] 0x539 dev group http://darcs.0x539.de/trac/obby/cgi-bin/trac.cgi
[Hirsch_Singhal] Hirsch Singhal Microsoft Corporation mailto:hirsin&microsoft.com 2016-03-03
[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
[Jean-Charles_Boude] Jean-Charles Boude Gangsta Ltd. mailto:jc&gangstamedia.com 2011-10-17
[Joakim_Johansson] Joakim Johansson mailto:joakim.johansson&tbricks.com
[John_Levine] John Levine mailto:standards&taugh.com 2016-07-26
[John_Wason] John Wason Wason Technology, LLC mailto:wason&wasontech.com 2014-01-27
[Kazuyuki_Ashimura] Kazuyuki Ashimura mailto:ashimura&w3.org 2022-11-22
[Michael_Stapelberg] Michael Stapelberg mailto:michael+iana&stapelberg.ch 2015-01-07
[Michael_Tennefoss] Michael Tennefoss mailto:mtennefoss&echelon.com
[Microsoft_Corporation_5] Microsoft Corporation mailto:hirsin&microsoft.com 2016-03-03
[Patrick_Stein] Patrick Stein mailto:Patrick.Stein&jinx.eu 2011-10-24
[Samuel_Jero] Samuel Jero mailto:sj323707&ohio.edu 2012-11-14
[Scott_Herscher_2] Scott Herscher mailto:scott&strixsystems.com
[Stuart_Cheshire] Stuart Cheshire mailto:cheshire&apple.com 2022-07-11
[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
[Wason_Technology_LLC] Wason Technology, LLC mailto:wason&wasontech.com 2014-01-27
[Yohei_Yoshihara] Yohei Yoshihara CX5 SOFTWARE mailto:yohei_yoshihara&cx5software.com 2013-02-04
[Zhang_Xinnan] Zhang Xinnan mailto:70331471&qq.com 2017-11-06