Service Name and Transport Protocol Port Number Registry

Last Updated

  • 2026-10-15

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
rmc 657 tcp RMC Michael Schmidt Michael Schmidt
rmc 657 udp RMC Michael Schmidt Michael Schmidt
fujitsu-mmpdc 1657 tcp fujitsu-mmpdc Katsumi Oomuro Katsumi Oomuro
fujitsu-mmpdc 1657 udp fujitsu-mmpdc Katsumi Oomuro Katsumi Oomuro
sns-dispatcher 2657 tcp SNS Dispatcher
sns-dispatcher 2657 udp SNS Dispatcher
immedianet-bcn 3657 tcp ImmediaNet Beacon Bill Homan Bill Homan 2003-01
immedianet-bcn 3657 udp ImmediaNet Beacon Bill Homan Bill Homan 2003-01
4647-4657 Unassigned
6569-6578 Unassigned
affiliate 6579 tcp Affiliate David Catmull David Catmull 2006-01
affiliate 6579 udp Affiliate David Catmull David Catmull 2006-01
6657 tcp Reserved
palcom-disc 6657 udp PalCom Discovery Boris Magnusson Boris Magnusson 2010-12-06
33657-33889 Unassigned

Contact Information

Name Contact URI Last Updated
Bill Homan bhoman&spanworks.com 2003-01
Boris Magnusson boris&cs.lth.se 2010-12-06
David Catmull uncommon&uncommonplace.com 2006-01
Katsumi Oomuro NAE01421&niftyserve.or.jp
Michael Schmidt mmaass&us.ibm.com