Service Name and Transport Protocol Port Number Registry

Last Updated
2026-09-11
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
249-255 Reserved 2024-12-20 [RFC 1060]
de-cache-query 1255 tcp de-cache-query
de-cache-query 1255 udp de-cache-query
vrtp 2255 tcp VRTP - ViRtue Transfer Protocol [Max_Fudim] [Max_Fudim]
vrtp 2255 udp VRTP - ViRtue Transfer Protocol [Max_Fudim] [Max_Fudim]
ads 2550 tcp ADS [Michael_O_Connor] [Michael_O_Connor]
ads 2550 udp ADS [Michael_O_Connor] [Michael_O_Connor]
isg-uda-server 2551 tcp ISG UDA Server [Dror_Harari] [Dror_Harari]
isg-uda-server 2551 udp ISG UDA Server [Dror_Harari] [Dror_Harari]
call-logging 2552 tcp Call Logging [Dean_Webb] [Dean_Webb]
call-logging 2552 udp Call Logging [Dean_Webb] [Dean_Webb]
efidiningport 2553 tcp efidiningport [Lynn_Carter] [Lynn_Carter]
efidiningport 2553 udp efidiningport [Lynn_Carter] [Lynn_Carter]
vcnet-link-v10 2554 tcp VCnet-Link v10 [Csaba_Mate] [Csaba_Mate]
vcnet-link-v10 2554 udp VCnet-Link v10 [Csaba_Mate] [Csaba_Mate]
compaq-wcp 2555 tcp Compaq WCP [Ferruccio_Barletta] [Ferruccio_Barletta]
compaq-wcp 2555 udp Compaq WCP [Ferruccio_Barletta] [Ferruccio_Barletta]
nicetec-nmsvc 2556 tcp nicetec-nmsvc
nicetec-nmsvc 2556 udp nicetec-nmsvc
nicetec-mgmt 2557 tcp nicetec-mgmt [Joerg_Paulus] [Joerg_Paulus]
nicetec-mgmt 2557 udp nicetec-mgmt [Joerg_Paulus] [Joerg_Paulus]
pclemultimedia 2558 tcp PCLE Multi Media [Jacob_Gsoedl] [Jacob_Gsoedl]
pclemultimedia 2558 udp PCLE Multi Media [Jacob_Gsoedl] [Jacob_Gsoedl]
lstp 2559 tcp LSTP [Waiki_Wright] [Waiki_Wright]
lstp 2559 udp LSTP [Waiki_Wright] [Waiki_Wright]
semaphore 3255 tcp Semaphore Connection Port [Jay_Eckles] [Jay_Eckles] 2002-02
semaphore 3255 udp Semaphore Connection Port [Jay_Eckles] [Jay_Eckles] 2002-02
5255-5263 Unassigned
mon 9255 tcp Manager On Network [David_Rouchet] [David_Rouchet] 2007-05
mon 9255 udp Manager On Network [David_Rouchet] [David_Rouchet] 2007-05
22538-22554 Unassigned
vocaltec-wconf 22555 tcp Vocaltec Web Conference [Scott_Petrack] [Scott_Petrack]
vocaltec-phone 22555 udp Vocaltec Internet Phone [Scott_Petrack] [Scott_Petrack]
22556-22762 Unassigned
25472-25575 Unassigned
sauterdongle 25576 tcp Sauter Dongle [Christian_Brecht] [Christian_Brecht] 2010-12-15
25576 udp Reserved
25577-25603 Unassigned

Contact Information

ID Name Contact URI Last Updated
[Christian_Brecht] Christian Brecht mailto:Christian.Brecht&sauter-gmbh.de 2010-12-15
[Csaba_Mate] Csaba Mate mailto:mc36&freemail.c3.hu
[David_Rouchet] David Rouchet mailto:david.rouchet&medialon.com 2007-05
[Dean_Webb] Dean Webb mailto:dean.webb&ascend.com
[Dror_Harari] Dror Harari mailto:Dror.Harari&isgsoft.com
[Ferruccio_Barletta] Ferruccio Barletta mailto:ferruccio.barletta&compaq.com
[Jacob_Gsoedl] Jacob Gsoedl mailto:jgsoedl&pinnaclesys.com
[Jay_Eckles] Jay Eckles mailto:ecklesweb&yahoo.com 2002-02
[Joerg_Paulus] Joerg Paulus mailto:tech&nicetec.de
[Lynn_Carter] Lynn Carter mailto:carterl&execpc.com
[Max_Fudim] Max Fudim mailto:fudim&virtue3d.com
[Michael_O_Connor] Michael O'Connor mailto:moconnor&adobe.com
[Scott_Petrack] Scott Petrack mailto:Scott_Petrack&vocaltec.com
[Waiki_Wright] Waiki Wright mailto:waiki&us.ibm.com