Service Name and Transport Protocol Port Number Registry

Last Updated
2026-08-17
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
gdoi 848 tcp GDOI [RFC3547]
gdoi 848 udp GDOI [RFC3547]
fjdocdist 1848 tcp fjdocdist [Yuichi_Ohiwa] [Yuichi_Ohiwa]
fjdocdist 1848 udp fjdocdist [Yuichi_Ohiwa] [Yuichi_Ohiwa]
amt-blc-port 2848 tcp AMT-BLC-PORT [Sandra_Frulloni] [Sandra_Frulloni]
amt-blc-port 2848 udp AMT-BLC-PORT [Sandra_Frulloni] [Sandra_Frulloni]
stun 3478 tcp Session Traversal Utilities for NAT (STUN) port [IESG] [IETF_Chair] 2019-03-28 [RFC8489]
stun 3478 udp Session Traversal Utilities for NAT (STUN) port [IESG] [IETF_Chair] 2019-03-28 [RFC8489]
item 3848 tcp IT Environmental Monitor [Keith_Wright] [Keith_Wright] 2003-08
item 3848 udp IT Environmental Monitor [Keith_Wright] [Keith_Wright] 2003-08
appserv-http 4848 tcp App Server - Admin HTTP
appserv-http 4848 udp App Server - Admin HTTP
stuns 5349 tcp Session Traversal Utilities for NAT (STUN) port [IESG] [IETF_Chair] 2019-03-28 [RFC8489]
7848-7868 Unassigned
netspeak-acd 21848 tcp NetSpeak Corp. Automatic Call Distribution [Toby_Hosterman] [Toby_Hosterman]
netspeak-acd 21848 udp NetSpeak Corp. Automatic Call Distribution [Toby_Hosterman] [Toby_Hosterman]
mtrace 33435 udp IP Multicast Traceroute [IESG] [IETF_Chair] 2017-12-13 2019-08-09 [RFC8487] Known Unauthorized Use on port 33435

Contact Information

ID Name Organization Contact URI Last Updated
[IESG] IESG mailto:iesg&ietf.org
[IETF_Chair] IETF Chair IETF mailto:chair&ietf.org
[Keith_Wright] Keith Wright mailto:kwright&sensatronics.com 2003-08
[Sandra_Frulloni] Sandra Frulloni mailto:frulloni.amtec&interbusiness.it
[Toby_Hosterman] Toby Hosterman mailto:root&netspeak.com
[Yuichi_Ohiwa] Yuichi Ohiwa mailto:y-ohiwa&ael.fujitsu.co.jp