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
sdnskmp 558 tcp SDNSKMP
sdnskmp 558 udp SDNSKMP
xingmpeg 1558 tcp xingmpeg [Howard_Gordon] [Howard_Gordon]
xingmpeg 1558 udp xingmpeg [Howard_Gordon] [Howard_Gordon]
pclemultimedia 2558 tcp PCLE Multi Media [Jacob_Gsoedl] [Jacob_Gsoedl]
pclemultimedia 2558 udp PCLE Multi Media [Jacob_Gsoedl] [Jacob_Gsoedl]
mcp-port 3558 tcp MCP user port [Professor_Paul_S_Wa] [Professor_Paul_S_Wa] 2002-07
mcp-port 3558 udp MCP user port [Professor_Paul_S_Wa] [Professor_Paul_S_Wa] 2002-07
4558 tcp Reserved
mtcevrunqman 4558 udp Marathon everRun Quorum Service Manager [David_Schwartz_2] [David_Schwartz_2] 2009-06-18
5558-5564 Unassigned
tmosms0 5580 tcp T-Mobile SMS Protocol Message 0 [Ezinne_Oji] [Ezinne_Oji] 2006-06
tmosms0 5580 udp T-Mobile SMS Protocol Message 0 [Ezinne_Oji] [Ezinne_Oji] 2006-06
tmosms1 5581 tcp T-Mobile SMS Protocol Message 1 [Ezinne_Oji] [Ezinne_Oji] 2006-06
tmosms1 5581 udp T-Mobile SMS Protocol Message 1 [Ezinne_Oji] [Ezinne_Oji] 2006-06
fac-restore 5582 tcp T-Mobile SMS Protocol Message 3 [Jessica_Yan] [Jessica_Yan] 2008-02-19
fac-restore 5582 udp T-Mobile SMS Protocol Message 3 [Jessica_Yan] [Jessica_Yan] 2008-02-19
tmo-icon-sync 5583 tcp T-Mobile SMS Protocol Message 2 [Donghwan_Lim] [Donghwan_Lim] 2008-01-22
tmo-icon-sync 5583 udp T-Mobile SMS Protocol Message 2 [Donghwan_Lim] [Donghwan_Lim] 2008-01-22
bis-web 5584 tcp BeInSync-Web [Adi_Ruppin] [Adi_Ruppin] 2005-08
bis-web 5584 udp BeInSync-Web [Adi_Ruppin] [Adi_Ruppin] 2005-08
bis-sync 5585 tcp BeInSync-sync [Adi_Ruppin] [Adi_Ruppin] 2005-08
bis-sync 5585 udp BeInSync-sync [Adi_Ruppin] [Adi_Ruppin] 2005-08
att-mt-sms 5586 tcp Planning to send mobile terminated SMS to the specific port so that the SMS is not visible to the client [ATT] [Dhillesh_Sigilipelli] 2014-08-21
5586 udp Reserved
5587-5596 Unassigned
xdsxdm 6558 tcp [Brian_Tackett] [Brian_Tackett] possible contact
xdsxdm 6558 udp [Brian_Tackett] [Brian_Tackett] possible contact
9556-9558 Unassigned
47558-47623 Unassigned

Contact Information

ID Name Organization Contact URI Last Updated
[Adi_Ruppin] Adi Ruppin mailto:adi.ruppin&data-pod.com 2005-08
[ATT] AT&T mailto:ds978v&att.com 2014-08-21
[Brian_Tackett] Brian Tackett mailto:cym&acrux.net
[David_Schwartz_2] David Schwartz mailto:david.schwartz&marathontechnologies.com 2009-06-18
[Dhillesh_Sigilipelli] Dhillesh Sigilipelli AT&T mailto:ds978v&att.com 2014-08-21
[Donghwan_Lim] Donghwan Lim mailto:donghwan.lim&t-mobile.com 2008-01-22
[Ezinne_Oji] Ezinne Oji mailto:ezinne.oji&t-mobile.com 2006-06
[Howard_Gordon] Howard Gordon mailto:hgordon&system.xingtech.com
[Jacob_Gsoedl] Jacob Gsoedl mailto:jgsoedl&pinnaclesys.com
[Jessica_Yan] Jessica Yan mailto:jessica.yan2&t-mobile.com 2008-02-19
[Professor_Paul_S_Wa] Professor Paul S. Wang mailto:pwang&cs.kent.edu 2002-07