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
tempo 526 tcp newdate
tempo 526 udp newdate
pdap-np 1526 tcp Prospero Data Access Prot non-priv [B_Clifford_Neuman] [B_Clifford_Neuman]
pdap-np 1526 udp Prospero Data Access Prot non-priv [B_Clifford_Neuman] [B_Clifford_Neuman]
ema-sent-lm 2526 tcp EMA License Manager [Thaddeus_Perala] [Thaddeus_Perala]
ema-sent-lm 2526 udp EMA License Manager [Thaddeus_Perala] [Thaddeus_Perala]
starquiz-port 3526 tcp starQuiz Port [Adam_Ernst_2] [Adam_Ernst_2] 2002-06
starquiz-port 3526 udp starQuiz Port [Adam_Ernst_2] [Adam_Ernst_2] 2002-06
5255-5263 Unassigned
3com-njack-1 5264 tcp 3Com Network Jack Port 1 [Abhay_Rajaram] [Abhay_Rajaram] 2003-03
3com-njack-1 5264 udp 3Com Network Jack Port 1 [Abhay_Rajaram] [Abhay_Rajaram] 2003-03
3com-njack-2 5265 tcp 3Com Network Jack Port 2 [Abhay_Rajaram] [Abhay_Rajaram] 2003-03
3com-njack-2 5265 udp 3Com Network Jack Port 2 [Abhay_Rajaram] [Abhay_Rajaram] 2003-03
5266-5268 Unassigned
xmpp-server 5269 tcp XMPP Server Connection [RFC6120]
5269 udp Reserved

Contact Information

ID Name Contact URI Last Updated
[Abhay_Rajaram] Abhay Rajaram mailto:Abhay_Rajaram&3com.com 2003-03
[Adam_Ernst_2] Adam Ernst mailto:contact&cosmicsoft.net 2002-06
[B_Clifford_Neuman] B. Clifford Neuman mailto:bcn&isi.edu 2022-02-18
[Thaddeus_Perala] Thaddeus Perala mailto:trperala&emaden.com