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
dsf 555 tcp
dsf 555 udp
livelan 1555 tcp livelan [Kaynam_Hedayat] [Kaynam_Hedayat]
livelan 1555 udp livelan [Kaynam_Hedayat] [Kaynam_Hedayat]
compaq-wcp 2555 tcp Compaq WCP [Ferruccio_Barletta] [Ferruccio_Barletta]
compaq-wcp 2555 udp Compaq WCP [Ferruccio_Barletta] [Ferruccio_Barletta]
razor 3555 tcp Vipul's Razor [Vipul_Ved_Prakash] [Vipul_Ved_Prakash] 2002-07
razor 3555 udp Vipul's Razor [Vipul_Ved_Prakash] [Vipul_Ved_Prakash] 2002-07
dsmipv6 4191 udp Dual Stack MIPv6 NAT Traversal [RFC 5555]
rsip 4555 tcp RSIP Port [RFC 3103]
rsip 4555 udp RSIP Port [RFC 3103]
cbus 5550 tcp Model Railway control using the CBUS message protocol [MERG] [Pete_Brownlow] 2017-01-03
5550 udp Reserved
5551-5552 Unassigned
sgi-eventmond 5553 tcp SGI Eventmond Port [Andrei_Vilkotski] [Andrei_Vilkotski] 2003-06
sgi-eventmond 5553 udp SGI Eventmond Port [Andrei_Vilkotski] [Andrei_Vilkotski] 2003-06
sgi-esphttp 5554 tcp SGI ESP HTTP [Vladimir_Legalov] [Vladimir_Legalov]
sgi-esphttp 5554 udp SGI ESP HTTP [Vladimir_Legalov] [Vladimir_Legalov]
personal-agent 5555 tcp Personal Agent [Jackie_Wu] [Jackie_Wu] Known UNAUTHORIZED USEs on port 5555
personal-agent 5555 udp Personal Agent [Jackie_Wu] [Jackie_Wu] Known UNAUTHORIZED USEs on port 5555
freeciv 5556 tcp Freeciv gameplay [Reinier_Post_and_Pau] [Reinier_Post_and_Pau] 2006-01 Known Unauthorized Use on port 5556
freeciv 5556 udp Freeciv gameplay [Reinier_Post_and_Pau] [Reinier_Post_and_Pau] 2006-01 Known Unauthorized Use on port 5556
farenet 5557 tcp Sandlab FARENET [Kay_T_Labinsky] [Kay_T_Labinsky] 2010-05-03
5557 udp Reserved
5558-5564 Unassigned
6552-6555 Unassigned
d-fence 8555 tcp SYMAX D-FENCE [Thomas_Geisel] [Thomas_Geisel] 2003-01
d-fence 8555 udp SYMAX D-FENCE [Thomas_Geisel] [Thomas_Geisel] 2003-01
trispen-sra 9555 tcp Trispen Secure Remote Access [Jaco_Botha] [Jaco_Botha] 2004-11
trispen-sra 9555 udp Trispen Secure Remote Access [Jaco_Botha] [Jaco_Botha] 2004-11
15364-15554 Unassigned
cisco-snat 15555 tcp Cisco Stateful NAT [Kaushik_Biswas] [Kaushik_Biswas] 2006-03
cisco-snat 15555 udp Cisco Stateful NAT [Kaushik_Biswas] [Kaushik_Biswas] 2006-03
15556-15659 Unassigned
ailith 17555 tcp Ailith management of routers [Thomas_Boje] [Thomas_Boje] 2014-03-27
17555 udp Reserved
21555-21589 Unassigned
vocaltec-wconf 22555 tcp Vocaltec Web Conference [Scott_Petrack] [Scott_Petrack]
vocaltec-phone 22555 udp Vocaltec Internet Phone [Scott_Petrack] [Scott_Petrack]
24555-24576 Unassigned
48130-48555 Unassigned

Contact Information

ID Name Organization Contact URI Last Updated
[Andrei_Vilkotski] Andrei Vilkotski mailto:andreiv&sgi.com 2003-06
[Ferruccio_Barletta] Ferruccio Barletta mailto:ferruccio.barletta&compaq.com
[Jackie_Wu] Jackie Wu mailto:jackiew&infoseek.com
[Jaco_Botha] Jaco Botha mailto:jaco.botha&trispen.com 2004-11
[Kaushik_Biswas] Kaushik Biswas mailto:kbiswas&cisco.com 2006-03
[Kay_T_Labinsky] Kay T. Labinsky mailto:Kay.Labinsky&sandlab.de 2010-05-03
[Kaynam_Hedayat] Kaynam Hedayat mailto:khedayat&roadrunner.pictel.com
[MERG] MERG mailto:merg&upsys.co.uk 2017-01-03
[Pete_Brownlow] Pete Brownlow mailto:merg&upsys.co.uk 2017-01-03
[Reinier_Post_and_Pau] Reinier Post and Paul Zastoupil mailto:freeciv&freeciv.org 2006-01
[Scott_Petrack] Scott Petrack mailto:Scott_Petrack&vocaltec.com
[Thomas_Boje] Thomas Boje mailto:thomas.boje&gmx.de 2014-03-27
[Thomas_Geisel] Thomas Geisel mailto:tgeisel&symax.de 2003-01
[Vipul_Ved_Prakash] Vipul Ved Prakash mailto:mail&vipul.net 2002-07
[Vladimir_Legalov] Vladimir Legalov mailto:legalov&sgi.com