Service Name and Transport Protocol Port Number Registry

Last Updated

  • 2026-11-06

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:

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

Available Formats

Service Name Port Number Transport Protocol Description Assignee Contact Registration Date Modification Date Reference Service Code Unauthorized Use Reported Assignment Notes
hks-lm 1722 tcp HKS License Manager Michael Wood Michael Wood
hks-lm 1722 udp HKS License Manager Michael Wood Michael Wood
11721-11722 Unassigned
avtp 17220 tcp IEEE 1722 Transport Protocol for Time Sensitive Applications Transport Protocol for Time-Sensitive Networking TG Ashley Butterworth 2014-03-07
avtp 17220 udp IEEE 1722 Transport Protocol for Time Sensitive Applications Transport Protocol for Time-Sensitive Networking TG Ashley Butterworth 2014-03-07
avdecc 17221 tcp IEEE 1722.1 AVB Discovery, Enumeration, Connection management, and Control IEEE-1722.1 Jeffrey Daniel Koftinoff 2011-11-01
avdecc 17221 udp IEEE 1722.1 AVB Discovery, Enumeration, Connection management, and Control IEEE-1722.1 Jeffrey Daniel Koftinoff 2011-11-01
17222 tcp Reserved
cpsp 17222 udp Control Plane Synchronization Protocol (SPSP) Randall Stewart Randall Stewart 2011-11-10
isa100-gci 17223 tcp ISA100 GCI is a service utilizing a common interface between an ISA100 Wireless gateway and a client application ISA100 Wireless Compliance Institute Jay Werb 2015-07-24
17223 udp Reserved
trdp-pd 17224 udp Train Realtime Data Protocol (TRDP) Process Data IEC Central Office Gianosvaldo Fadin 2015-07-24
17224 tcp Reserved
trdp-md 17225 tcp Train Realtime Data Protocol (TRDP) Message Data IEC Central Office Gianosvaldo Fadin 2015-07-24
trdp-md 17225 udp Train Realtime Data Protocol (TRDP) Message Data IEC Central Office Gianosvaldo Fadin 2015-07-24
17226-17233 Unassigned

Contact Information

Name Organization Contact URI Last Updated
Ashley Butterworth abutterworth&apple.com 2014-03-07
Gianosvaldo Fadin IEC Central Office gianosvaldo.fadin&anie.it 2015-07-24
IEEE-1722.1 jeff.koftinoff&ieee.com 2011-11-01
IEC Central Office cj&iec.ch 2015-07-24
ISA100 Wireless Compliance Institute jay&jwerb.com 2015-07-24
Jay Werb ISA100 Wireless Compliance Institute jay&jwerb.com 2015-07-24
Jeffrey Daniel Koftinoff IEEE-1722.1 jeff.koftinoff&ieee.com 2011-11-01
Michael Wood wood&althea.hks.com
Randall Stewart rrs&lakerest.net 2011-10-24
Transport Protocol for Time-Sensitive Networking TG AVBTP&ieee.org 2014-03-07