Service Name and Transport Protocol Port Number Registry

Last Updated

  • 2026-10-22

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
iax 4569 tcp Inter-Asterisk eXchange Benjamin Kowarsch Benjamin Kowarsch RFC 5456 Defined TXT keys:
auth plaintext | md5 | rsakeys
userid alphanumeric, additionally '_', '+', '-'
secret any printable ASCII characters
domain any DNS domain name or IP address
extension alphanumeric, additionally '*', '#', '_', '+', '-'
context alphanumeric, additionally '_', '+', '-'
trunk yes | no | 0 | 1
welcome alphanumeric, additionally '*', '#', '_', '+', '-'
voicemail alphanumeric, additionally '*', '#', '_', '+', '-'
reception alphanumeric, additionally '*', '#', '_', '+', '-'
echotest alphanumeric, additionally '*', '#', '_', '+', '-'
ivrtest alphanumeric, additionally '*', '#', '_', '+', '-'
All of these TXT record keys are optional, they may be omitted. Further keys may be added in the future.
iax 4569 udp Inter-Asterisk eXchange Benjamin Kowarsch Benjamin Kowarsch RFC 5456 Defined TXT keys:
auth plaintext | md5 | rsakeys
userid alphanumeric, additionally '_', '+', '-'
secret any printable ASCII characters
domain any DNS domain name or IP address
extension alphanumeric, additionally '*', '#', '_', '+', '-'
context alphanumeric, additionally '_', '+', '-'
trunk yes | no | 0 | 1
welcome alphanumeric, additionally '*', '#', '_', '+', '-'
voicemail alphanumeric, additionally '*', '#', '_', '+', '-'
reception alphanumeric, additionally '*', '#', '_', '+', '-'
echotest alphanumeric, additionally '*', '#', '_', '+', '-'
ivrtest alphanumeric, additionally '*', '#', '_', '+', '-'
All of these TXT record keys are optional, they may be omitted. Further keys may be added in the future.

Contact Information

Name Contact URI Last Updated
Benjamin Kowarsch benjamin&sunrise-tel.com 2004-11