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]

Available Formats

CSV

XML

HTML

Plain text
Service Name Port Number Transport Protocol Description Assignee Contact Registration Date Modification Date Reference Service Code Unauthorized Use Reported Assignment Notes
corba-iiop 683 tcp CORBA IIOP
corba-iiop 683 udp CORBA IIOP
ncpm-hip 1683 tcp ncpm-hip [Ken_Hearn] [Ken_Hearn]
ncpm-hip 1683 udp ncpm-hip [Ken_Hearn] [Ken_Hearn]
ncdloadbalance 2683 tcp NCDLoadBalance [Tim_Stevenson] [Tim_Stevenson]
ncdloadbalance 2683 udp NCDLoadBalance [Tim_Stevenson] [Tim_Stevenson]
bmc-ea 3683 tcp BMC EDV/EA [Portnoy_Boxman] [Portnoy_Boxman] 2003-01
bmc-ea 3683 udp BMC EDV/EA [Portnoy_Boxman] [Portnoy_Boxman] 2003-01
spike 4683 tcp Spike Clipboard Service [Scott_Herscher] [Scott_Herscher] 2005-08
spike 4683 udp Spike Clipboard Service [Scott_Herscher] [Scott_Herscher] 2005-08
coap 5683 tcp Constrained Application Protocol (CoAP) [IESG] [IETF_Chair] 2017-12-22 [RFC8323]
coap 5683 udp Constrained Application Protocol [IESG] [IETF_Chair] 2011-06-13 2013-07-25 [RFC7252]
6818-6830 Unassigned
ambit-lm 6831 tcp ambit-lm [Don_Hejna] [Don_Hejna]
ambit-lm 6831 udp ambit-lm [Don_Hejna] [Don_Hejna]
6832-6840 Unassigned
dmt 7683 tcp Cleondris DMT [Cleondris_GmbH] [Christian_Plattner] 2015-03-31
7683 udp Reserved

Contact Information

ID Name Organization Contact URI Last Updated
[Christian_Plattner] Christian Plattner Cleondris GmbH mailto:christian.plattner&cleondris.ch 2015-03-31
[Cleondris_GmbH] Cleondris GmbH mailto:noc&cleondris.ch 2015-03-31
[Don_Hejna] Don Hejna mailto:djhejna&ambit.com
[IESG] IESG mailto:iesg&ietf.org
[IETF_Chair] IETF Chair IETF mailto:chair&ietf.org
[Ken_Hearn] Ken Hearn mailto:hearn&hpindacx.cup.hp.com
[Portnoy_Boxman] Portnoy Boxman mailto:portnoy_boxman&bmc.com 2005-01
[Scott_Herscher] Scott Herscher mailto:scott&porchdogsoft.com 2005-08
[Tim_Stevenson] Tim Stevenson mailto:tes&ncd.com