Service Name and Transport Protocol Port Number Registry

Last Updated
2026-09-02
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
new-rwho 550 tcp new-who [n/a]
new-rwho 550 udp new-who [n/a]
3m-image-lm 1550 tcp Image Storage license manager 3M Company [J_C_Canessa] [J_C_Canessa]
3m-image-lm 1550 udp Image Storage license manager 3M Company [J_C_Canessa] [J_C_Canessa]
ads 2550 tcp ADS [Michael_O_Connor] [Michael_O_Connor]
ads 2550 udp ADS [Michael_O_Connor] [Michael_O_Connor]
ssmpp 3550 tcp Secure SMPP [Cormac_Long] [Cormac_Long] 2002-07
ssmpp 3550 udp Secure SMPP [Cormac_Long] [Cormac_Long] 2002-07
gds-adppiw-db 4550 tcp Perman I Interbase Server [Leo_Lesage] [Leo_Lesage] 2006-04
gds-adppiw-db 4550 udp Perman I Interbase Server [Leo_Lesage] [Leo_Lesage] 2006-04
fcp-addr-srvr1 5500 tcp fcp-addr-srvr1 [Ken_Wittmer] [Ken_Wittmer]
fcp-addr-srvr1 5500 udp fcp-addr-srvr1 [Ken_Wittmer] [Ken_Wittmer]
fcp-addr-srvr2 5501 tcp fcp-addr-srvr2 [Ken_Wittmer] [Ken_Wittmer]
fcp-addr-srvr2 5501 udp fcp-addr-srvr2 [Ken_Wittmer] [Ken_Wittmer]
fcp-srvr-inst1 5502 tcp fcp-srvr-inst1 [Ken_Wittmer] [Ken_Wittmer]
fcp-srvr-inst1 5502 udp fcp-srvr-inst1 [Ken_Wittmer] [Ken_Wittmer]
fcp-srvr-inst2 5503 tcp fcp-srvr-inst2 [Ken_Wittmer] [Ken_Wittmer]
fcp-srvr-inst2 5503 udp fcp-srvr-inst2 [Ken_Wittmer] [Ken_Wittmer]
fcp-cics-gw1 5504 tcp fcp-cics-gw1 [Ken_Wittmer] [Ken_Wittmer]
fcp-cics-gw1 5504 udp fcp-cics-gw1 [Ken_Wittmer] [Ken_Wittmer]
checkoutdb 5505 tcp Checkout Database [Dirk_Stoop] [Dirk_Stoop] 2007-04
checkoutdb 5505 udp Checkout Database [Dirk_Stoop] [Dirk_Stoop] 2007-04
amc 5506 tcp Amcom Mobile Connect [Aaron_Fracht_Monroe] [Aaron_Fracht_Monroe] 2010-06-03
amc 5506 udp Amcom Mobile Connect [Aaron_Fracht_Monroe] [Aaron_Fracht_Monroe] 2010-06-03
psl-management 5507 tcp PowerSysLab Electrical Management [PowerSysLab] [Lucas_Lorensi] 2015-07-20
5507 udp Reserved
5508-5539 Unassigned
cbus 5550 tcp Model Railway control using the CBUS message protocol [MERG] [Pete_Brownlow] 2017-01-03
5550 udp Reserved
fg-sysupdate 6550 tcp fg-sysupdate [Mark_Beyer] [Mark_Beyer]
fg-sysupdate 6550 udp fg-sysupdate [Mark_Beyer] [Mark_Beyer]
7550 tcp Reserved
cloudsignaling 7550 udp Cloud Signaling Service [Scott_Dawson] [Scott_Dawson] 2011-07-01

Contact Information

ID Name Organization Contact URI Last Updated
[Aaron_Fracht_Monroe] Aaron Fracht-Monroe mailto:afracht-monroe&amcomsoft.com 2010-06-03
[Cormac_Long] Cormac Long mailto:webmaster&smsforum.net 2002-07
[Dirk_Stoop] Dirk Stoop mailto:dirk&madebysofa.com 2007-04
[J_C_Canessa] J. C. Canessa mailto:jccanessa&mmm.com
[Ken_Wittmer] Ken Wittmer mailto:kenneth.m.wittmer&accenture.com
[Leo_Lesage] Leo Lesage mailto:leo.lesage&adp.nl 2006-04
[Lucas_Lorensi] Lucas Lorensi mailto:lucas.lorensi&powersyslab.com 2015-07-20
[Mark_Beyer] Mark Beyer mailto:mbeyer&freegate.com
[MERG] MERG mailto:merg&upsys.co.uk 2017-01-03
[Michael_O_Connor] Michael O'Connor mailto:moconnor&adobe.com
[Pete_Brownlow] Pete Brownlow mailto:merg&upsys.co.uk 2017-01-03
[PowerSysLab] PowerSysLab mailto:info&powersyslab.com 2015-07-20
[Scott_Dawson] Scott Dawson mailto:sdawson&arbor.net 2011-07-01