Service Name and Transport Protocol Port Number Registry

Last Updated

2026-10-13

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: Internet Assigned Numbers Authority (IANA) Procedures for the Management of the Service Name and Transport Protocol Port Number Registry

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 basis, as described in RFC 6335.

Port numbers are divided into three ranges, with their uses and assignment procedures specified in Section 8.1.2 of RFC 6335:

System Ports (0-1023) are assigned using the IETF Review or IESG Approval procedures.
User Ports (1024-49151) are assigned using the IETF Review, IESG Approval, or Expert Review procedures.
Dynamic and/or Private Ports (49152-65535) are not assigned.

The registration procedures for service names and port numbers are specified in RFC 6335, while the registration policies referenced above are defined in RFC 8126.

Assigned ports both System and User ports SHOULD NOT be used without or prior to IANA registration.

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.

Registration Forms

To request a new assignment, please use the Application for Service Names and User Port Numbers form.
To modify an existing assignment, please use the Modify a Port Number Assignment form.

Available Formats

Service Name	Port Number	Transport Protocol	Description	Assignee	Contact	Registration Date	Assignment Notes
aed-512	149	tcp	AED 512 Emulation Service	Albert G. Broscius	Albert G. Broscius
aed-512	149	udp	AED 512 Emulation Service	Albert G. Broscius	Albert G. Broscius
exec	512	tcp	remote process execution; authentication performed using passwords and UNIX login names
comsat	512	udp
biff	512	udp	used by mail system to notify users of new mail received; currently receives messages only from processes on the same machine
wins	1512	tcp	Microsoft's Windows Internet Name Service	Pradeep Bahl	Pradeep Bahl
wins	1512	udp	Microsoft's Windows Internet Name Service	Pradeep Bahl	Pradeep Bahl
citrixima	2512	tcp	Citrix IMA
citrixima	2512	udp	Citrix IMA
aztec	3512	tcp	Aztec Distribution Port	Alan Francis	Alan Francis	2002-05
aztec	3512	udp	Aztec Distribution Port	Alan Francis	Alan Francis	2002-05
barracuda-bbs	5120	tcp	Barracuda Backup Protocol	Barracuda Networks	Andrew Blyler	2013-04-05
barracuda-bbs	5120	udp	Barracuda Backup Protocol	Barracuda Networks	Andrew Blyler	2013-04-05
	5121-5132		Unassigned
	6512-6512		Unassigned
	7512-7541		Unassigned
lumiere		tcp	A protocol to remotely control DMX512 devices over the network	Gangsta Ltd.	Jean-Charles Boude	2011-10-13	Defined TXT keys: None

Contact Information

Name	Organization	Contact URI	Last Updated
Alan Francis		AlanF&zonal.co.uk	2002-05
Albert G. Broscius		broscius&dsl.cis.upenn.edu
Andrew Blyler	Barracuda Networks	ablyler&barracuda.com	2013-04-05
	Barracuda Networks	BackupEngineering_Team&barracuda.com	2013-04-05
	Gangsta Ltd.	jc&gangstamedia.com	2011-10-13
Jean-Charles Boude	Gangsta Ltd.	jc&gangstamedia.com	2011-10-17
Pradeep Bahl		pradeepb&microsoft.com