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
[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
pt-tls 271 tcp IETF Network Endpoint Assessment (NEA) Posture Transport Protocol over TLS (PT-TLS) [IESG] [IETF_Chair] 2012-07-31 [RFC6876]
271 udp Reserved
excw 1271 tcp eXcW [Norm_Freedman] [Norm_Freedman]
excw 1271 udp eXcW [Norm_Freedman] [Norm_Freedman]
mmcals 2271 tcp Secure Meeting Maker Scheduling
mmcals 2271 udp Secure Meeting Maker Scheduling
sso-service 2710 tcp SSO Service
sso-service 2710 udp SSO Service
sso-control 2711 tcp SSO Control [Axel_Kern] [Axel_Kern]
sso-control 2711 udp SSO Control [Axel_Kern] [Axel_Kern]
aocp 2712 tcp Axapta Object Communication Protocol [Jakob_Steen_Hansen] [Jakob_Steen_Hansen]
aocp 2712 udp Axapta Object Communication Protocol [Jakob_Steen_Hansen] [Jakob_Steen_Hansen]
raventbs 2713 tcp Raven Trinity Broker Service
raventbs 2713 udp Raven Trinity Broker Service
raventdm 2714 tcp Raven Trinity Data Mover [Daniel_Sorlov] [Daniel_Sorlov]
raventdm 2714 udp Raven Trinity Data Mover [Daniel_Sorlov] [Daniel_Sorlov]
hpstgmgr2 2715 tcp HPSTGMGR2 [Kevin_Collins_2] [Kevin_Collins_2]
hpstgmgr2 2715 udp HPSTGMGR2 [Kevin_Collins_2] [Kevin_Collins_2]
inova-ip-disco 2716 tcp Inova IP Disco [Chris_Koeritz] [Chris_Koeritz]
inova-ip-disco 2716 udp Inova IP Disco [Chris_Koeritz] [Chris_Koeritz]
pn-requester 2717 tcp PN REQUESTER
pn-requester 2717 udp PN REQUESTER
pn-requester2 2718 tcp PN REQUESTER 2 [Portnoy_Boxman] [Portnoy_Boxman]
pn-requester2 2718 udp PN REQUESTER 2 [Portnoy_Boxman] [Portnoy_Boxman]
scan-change 2719 tcp Scan & Change [Alexander_Raji] [Alexander_Raji]
scan-change 2719 udp Scan & Change [Alexander_Raji] [Alexander_Raji]
csoft-prev 3271 tcp CSoft Prev Port [Nedelcho_Stanev_3] [Nedelcho_Stanev_3]
csoft-prev 3271 udp CSoft Prev Port [Nedelcho_Stanev_3] [Nedelcho_Stanev_3]
nut 3493 tcp Network UPS Tools [Network_UPS_Tools_Project] [Evgeny_Klimov] 2002-05 2022-05-18 [RFC9271]
cuelink 5271 tcp StageSoft CueLink messaging [Todd_Pichler] [Todd_Pichler] 2010-03-26
cuelink-disc 5271 udp StageSoft CueLink discovery [Todd_Pichler] [Todd_Pichler] 2010-03-26
7263-7271 Unassigned
8271-8275 Unassigned
23054-23271 Unassigned

Contact Information

ID Name Organization Contact URI Last Updated
[Alexander_Raji] Alexander Raji mailto:araji&lucent.com
[Axel_Kern] Axel Kern mailto:axel.kern&betasystems.com
[Chris_Koeritz] Chris Koeritz mailto:ckoeritz&inovacorp.com
[Daniel_Sorlov] Daniel Sorlov mailto:Daniel&sorlov.com
[Evgeny_Klimov] Evgeny Klimov mailto:jimklimov+nut&gmail.com 2020-12-16
[IESG] IESG mailto:iesg&ietf.org
[IETF_Chair] IETF Chair IETF mailto:chair&ietf.org
[Jakob_Steen_Hansen] Jakob Steen Hansen mailto:jsh&dk.damgaard.com
[Kevin_Collins_2] Kevin Collins mailto:kevinc&cnd.hp.com
[Nedelcho_Stanev_3] Nedelcho Stanev mailto:decho&iname.com
[Network_UPS_Tools_Project] Network UPS Tools Project mailto:iana&networkupstools.org 2020-12-16
[Norm_Freedman] Norm Freedman mailto:normfree&san.rr.com 2003-08
[Portnoy_Boxman] Portnoy Boxman mailto:portnoy_boxman&bmc.com 2005-01
[Todd_Pichler] Todd Pichler mailto:todd.pichler&stagesoft.com 2010-03-26