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
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>
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>
csi-mmws tcp Canfield Scientific Inc - Mirror Mobile Web Services [Canfield_Scientific_Inc] [James_Crismale] 2013-07-02 Defined TXT keys: path
gopro-web udp GoPro proprietary protocol for devices [GoPro] [Joe_Enke] 2014-10-13 Defined TXT keys: model, fw_version, platform_version, protocol_version, mac_address
hg Mercurial web-based repository access Defined TXT keys: None path=<file system pathname to repository> description=<descriptive name of repository>
https tcp HTTP over SSL/TLS [Tim_Berners_Lee] [Tim_Berners_Lee] Web browsers like Safari and Internet Explorer (with the Bonjour for Windows plugin) DO NOT browse for DNS-SD service type "_https._tcp" in addition to browsing for "_http._tcp". This is a conscious decision to reduce proliferation of service types, to help keep DNS-SD efficient on the network. Today, if a user types http://www.mybank.com/ into their web browser, the web server automatically redirects the user to https://www.mybank.com/. Rather than having an entirely different DNS-SD service type for https, we recommend using the same redirection mechanism: advertise a plain "http" service, which consists of nothing except an HTTP redirection to the desired "https" URL. Work is currently being done on adding mechanisms to HTTP and TLS to allow the server to tell the client that it needs to activate TLS on the current connection before proceeding. If this becomes widely adopted, it further justifies the decision to not create a separate DNS-SD service type "_https._tcp", because security becomes just another one of the things that is negotiated on a per-connection basis (like content-type negotiation today) rather than being an entirely separate thing.
idcws Intermec Device Configuration Web Services [Thaddeus_Ternes] [Thaddeus_Ternes] Defined TXT keys: version=<x.xx>
itis-device IT-IS International Ltd. Device [Ben_Webster] [Ben_Webster] Defined TXT keys: type=<product type> configuration=<product configuration> description=<human readable description> version=<device and protocol version>
ocaws tcp Insecure OCP.1 hosted on a WebSocket [OCA_Alliance] [Stephan_van_Tienen] 2017-05-19 Defined TXT keys: txtvers protovers path
ola tcp Web Interface for the Open Lighting Architecture Software [Open_Lighting_Project] [Simon_Newton_2] 2013-12-09 2014-02-25 Subtypes: _www-http Defined TXT keys: None
omni-bookmark OmniWeb [The_Omni_Group] [The_Omni_Group] Defined TXT keys: None
owhttpd OWFS (1-wire file system) web server [Paul_H_Alfille] [Paul_H_Alfille] Defined TXT keys: txtvers
pipedal tcp Pi Pedal Web Interface [Robin_Davies] [Robin_Davies] 2021-08-18 Defined TXT keys: None
psap udp Progal Service Advertising Protocol [Soren_Weber] [Soren_Weber] Defined TXT keys: c0, c1, ..., cn
slimhttp SliMP3 Server Web Interface [Dean_Blackketter_2] [Dean_Blackketter_2] Defined TXT keys: None
uwsgi Unbit Web Server Gateway Interface [Roberto_De_Ioris] [Roberto_De_Ioris] Defined TXT keys: None
web-xi tcp HTTP-based protocol for DAQ devices [Spectris_plc] [Carsten_Hansen] 2019-02-13 Defined TXT keys: name, version
webex tcp Cisco WebEx serials products will release Bonjour based service [Mobile_Team] [Aulion_Huang] 2018-02-09 Defined TXT keys: None
webex udp Cisco WebEx serials products will release Bonjour based service [Mobile_Team] [Aulion_Huang] 2018-02-09 Defined TXT keys: None
webdav World Wide Web Distributed Authoring and Versioning (WebDAV) [Y_Y_Goland] [Y_Y_Goland] Defined TXT keys: u=<username> p=<password> path=<path>
webdavs WebDAV over SSL/TLS [Y_Y_Goland] [Y_Y_Goland] Defined TXT keys: u=<username> p=<password> path=<path>
webissync WebIS Sync Protocol [Alex_Kac] [Alex_Kac] Defined TXT keys: None
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.

ws Web Services [Andrew_Donoho] [Andrew_Donoho] Defined TXT keys: None

Contact Information

ID Name Organization Contact URI Last Updated
[Alex_Kac] Alex Kac mailto:webis_sync_protocol&webis.net
[Andrew_Donoho] Andrew Donoho mailto:awd&us.ibm.com
[Aulion_Huang] Aulion Huang mailto:aulionh&cisco.com 2018-02-09
[Ben_Webster] Ben Webster mailto:b.webster&itisint.com
[Canfield_Scientific_Inc] Canfield Scientific, Inc. mailto:jim.crismale&canfieldsci.com 2013-07-02
[Carsten_Hansen] Carsten Hansen Spectris plc mailto:Carsten.Hansen&bksv.com 2019-02-13
[Dean_Blackketter_2] Dean Blackketter mailto:dean&slimdevices.com
[GoPro] GoPro mailto:jenke&gopro.com 2014-10-13
[IESG] IESG mailto:iesg&ietf.org
[IETF_Chair] IETF Chair IETF mailto:chair&ietf.org
[James_Crismale] James Crismale Canfield Scientific, Inc. mailto:jim.crismale&canfieldsci.com 2013-07-02
[Joe_Enke] joe enke GoPro mailto:jenke&gopro.com 2014-10-13
[Kazuyuki_Ashimura] Kazuyuki Ashimura mailto:ashimura&w3.org 2022-11-22
[Mobile_Team] Mobile Team mailto:group.felix&cisco.com 2018-02-09
[OCA_Alliance] OCA Alliance mailto:tina.lipscomb&oca-alliance.com 2017-05-19
[Open_Lighting_Project] Open Lighting Project mailto:simon&nomis52.net 2013-12-09
[Paul_H_Alfille] Paul H Alfille mailto:paul.alfille&gmail.com
[Roberto_De_Ioris] Roberto De Ioris mailto:info&unbit.it
[Robin_Davies] Robin Davies mailto:rerdavies&gmail.com 2021-08-18
[Simon_Newton_2] Simon Newton mailto:simon&nomis52.net 2013-12-09
[Soren_Weber] Soren Weber mailto:sw&ditec-gmbh.de
[Spectris_plc] Spectris plc mailto:Carsten.Hansen&bksv.com 2019-02-13
[Stephan_van_Tienen] Stephan van Tienen OCA Alliance mailto:stephan.vantienen&bosch.com 2017-05-19
[Thaddeus_Ternes] Thaddeus Ternes mailto:thaddeus.ternes&intermec.com
[The_Omni_Group] The Omni Group mailto:info&omnigroup.com 2020-07-10
[Tim_Berners_Lee] Tim Berners-Lee mailto:timbl&w3.org
[W3C_Web_of_Things_Working_Group] W3C Web of Things Working Group mailto:team-wot&w3.org 2022-11-22
[Y_Y_Goland] Y. Y. Goland mailto:yarong&microsoft.com