Internet Assigned Numbers Authority

Service Name and Transport Protocol Port Number Registry

Last Updated
2025-08-26
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
rpki-rtr 323 tcp Resource PKI to Router Protocol [IESG] [IETF_Chair] [RFC6810]
323 udp Reserved
h323hostcallsc 1300 tcp H.323 Secure Call Control Signalling [ITU-T] [ITU-T_TSB] 2013-01-31
h323hostcallsc 1300 udp H.323 Secure Call Control Signalling [ITU-T] [ITU-T_TSB] 2013-01-31
brcd 1323 tcp brcd [Todd_Picquelle] [Todd_Picquelle]
brcd 1323 udp brcd [Todd_Picquelle] [Todd_Picquelle]
h323gatedisc 1718 tcp H.323 Multicast Gatekeeper Discover [ITU-T] [ITU-T_TSB] 2013-01-31
h323gatedisc 1718 udp H.323 Multicast Gatekeeper Discover [ITU-T] [ITU-T_TSB] 2013-01-31
h323gatestat 1719 tcp H.323 Unicast Gatekeeper Signaling [ITU-T] [ITU-T_TSB] 2013-01-31
h323gatestat 1719 udp H.323 Unicast Gatekeeper Signaling [ITU-T] [ITU-T_TSB] 2013-01-31
h323hostcall 1720 tcp H.323 Call Control Signalling [ITU-T] [ITU-T_TSB] 2013-01-31
h323hostcall 1720 udp H.323 Call Control Signalling [ITU-T] [ITU-T_TSB] 2013-01-31
h323hostcall 1720 sctp H.323 Call Control [ITU-T] 2014-07-30
3d-nfsd 2323 tcp 3d-nfsd [Mike_Sherrill] [Mike_Sherrill]
3d-nfsd 2323 udp 3d-nfsd [Mike_Sherrill] [Mike_Sherrill]
call-sig-trans 2517 tcp H.323 Annex E Call Control Signalling Transport [ITU-T] [ITU-T_TSB] 2013-01-31
call-sig-trans 2517 udp H.323 Annex E Call Control Signalling Transport [ITU-T] [ITU-T_TSB] 2013-01-31
sftdst-port 3230 tcp Software Distributor Port [Andrea_Lanza] [Andrea_Lanza] 2014-02-21
sftdst-port 3230 udp Software Distributor Port [Andrea_Lanza] [Andrea_Lanza] 2014-02-21
vidigo 3231 tcp VidiGo communication (previous was: Delta Solutions Direct) [Peter_Ijkhout] [Peter_Ijkhout]
vidigo 3231 udp VidiGo communication (previous was: Delta Solutions Direct) [Peter_Ijkhout] [Peter_Ijkhout]
mdtp 3232 tcp MDT port 2012-02-21 [RFC6513]
mdtp 3232 udp MDT port 2012-02-21 [RFC6513]
whisker 3233 tcp WhiskerControl main port [Rudolf_Cardinal] [Rudolf_Cardinal] 2002-02
whisker 3233 udp WhiskerControl main port [Rudolf_Cardinal] [Rudolf_Cardinal] 2002-02
alchemy 3234 tcp Alchemy Server [Mikhail_Belov] [Mikhail_Belov] 2002-02
alchemy 3234 udp Alchemy Server [Mikhail_Belov] [Mikhail_Belov] 2002-02
mdap-port 3235 tcp MDAP port [Johan_Deleu] [Johan_Deleu] 2002-02
mdap-port 3235 udp MDAP Port [Johan_Deleu] [Johan_Deleu] 2002-02
apparenet-ts 3236 tcp appareNet Test Server
apparenet-ts 3236 udp appareNet Test Server
apparenet-tps 3237 tcp appareNet Test Packet Sequencer
apparenet-tps 3237 udp appareNet Test Packet Sequencer
apparenet-as 3238 tcp appareNet Analysis Server
apparenet-as 3238 udp appareNet Analysis Server
apparenet-ui 3239 tcp appareNet User Interface [Fred_Klassen] [Fred_Klassen] 2002-02
apparenet-ui 3239 udp appareNet User Interface [Fred_Klassen] [Fred_Klassen] 2002-02
trim-ice 4323 tcp TRIM ICE Service [Siva_Poobalasingam_2] [Siva_Poobalasingam_2] 2007-02
trim-ice 4323 udp TRIM ICE Service [Siva_Poobalasingam_2] [Siva_Poobalasingam_2] 2007-02
coap 5683 tcp Constrained Application Protocol (CoAP) [IESG] [IETF_Chair] 2017-12-22 [RFC8323]
coaps 5684 tcp Constrained Application Protocol (CoAP) [IESG] [IETF_Chair] 2017-12-22 [RFC7301][RFC8323]
6323 Unassigned
8323-8350 Unassigned
h323callsigalt 11720 tcp H.323 Call Control Signalling Alternate [ITU-T] [ITU-T_TSB] 2013-01-31
h323callsigalt 11720 udp H.323 Call Control Signalling Alternate [ITU-T] [ITU-T_TSB] 2013-01-31
12323-12344 Unassigned
vrmg-ip 24323 tcp Verimag mobile class protocol over TCP [Verimag_OOO] [Denis_Ionov] 2018-08-15
24323 udp Reserved
32250-32399 Unassigned
pmwebapi 44323 tcp HTTP binding for Performance Co-Pilot client API [Performance_Co-Pilot_PCP_Project] [Ken_McDonell_2] 2013-10-09
44323 udp Unassigned "pcp" assignment withdrawn, moved to port 5351 per RFC6887
h323 H.323 Real-time audio, video and data communication call setup protocol [Will_MacDonald] [Will_MacDonald] Defined TXT keys: None

Contact Information

ID Name Organization Contact URI Last Updated
[Andrea_Lanza] Andrea Lanza mailto:andrea&andrealanza.eu 2014-02-21
[Denis_Ionov] Denis Ionov Verimag, OOO mailto:iddi&verimag.ru 2018-07-20
[Fred_Klassen] Fred Klassen mailto:fklassen&jaalam.com 2002-02
[IESG] IESG mailto:iesg&ietf.org
[IETF_Chair] IETF Chair IETF mailto:chair&ietf.org
[ITU-T] ITU-T mailto:tsbsg16&itu.int 2013-01-31
[ITU-T_TSB] ITU-T TSB ITU-T mailto:tsbsg16&itu.int 2013-01-31
[Johan_Deleu] Johan Deleu mailto:johan.deleu&alcatel.be 2002-02
[Ken_McDonell_2] Ken_McDonell mailto:kenj&internode.on.net 2013-10-09
[Mike_Sherrill] Mike Sherrill mailto:sherrill&commvault.com
[Mikhail_Belov] Mikhail Belov mailto:mikhail&imrgold.com 2002-02
[Performance_Co-Pilot_PCP_Project] Performance Co-Pilot (PCP) Project mailto:kenj&internode.on.net 2013-10-09
[Peter_Ijkhout] Peter Ijkhout mailto:peter&deltasolutions.nl
[Rudolf_Cardinal] Rudolf Cardinal mailto:rudolf&pobox.com 2002-02
[Siva_Poobalasingam_2] Siva Poobalasingam mailto:Siva.Poobalasingam&towersoft.com.au 2007-02
[Todd_Picquelle] Todd Picquelle mailto:todd&picquelle.com
[Verimag_OOO] Verimag, OOO mailto:support&verimag.ru 2018-07-20
[Will_MacDonald] Will MacDonald mailto:will&codian.com