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
nsw-fe 27 tcp NSW User System FE [Robert_Thomas] [Robert_Thomas]
nsw-fe 27 udp NSW User System FE [Robert_Thomas] [Robert_Thomas]
locus-con 127 tcp Locus PC-Interface Conn Server [Eric_Peterson] [Eric_Peterson]
locus-con 127 udp Locus PC-Interface Conn Server [Eric_Peterson] [Eric_Peterson]
dsp3270 246 tcp Display Systems Protocol [Weldon_J_Showalter] [Weldon_J_Showalter]
dsp3270 246 udp Display Systems Protocol [Weldon_J_Showalter] [Weldon_J_Showalter]
270 tcp Reserved
gist 270 udp Q-mode encapsulation for GIST messages [RFC5971]
pt-tls 271 tcp IETF Network Endpoint Assessment (NEA) Posture Transport Protocol over TLS (PT-TLS) [IESG] [IETF_Chair] 2012-07-31 [RFC6876]
271 udp Reserved
272-279 Unassigned
svrloc 427 tcp Server Location [Veizades] [Veizades]
svrloc 427 udp Server Location [Veizades] [Veizades]
stx 527 tcp Stock IXChange [Ferdi_Ladeira] [Ferdi_Ladeira] 2022-01-25
stx 527 udp Stock IXChange [Ferdi_Ladeira] [Ferdi_Ladeira] 2022-01-25
soap-beep 605 tcp SOAP over BEEP [RFC4227]
soap-beep 605 udp SOAP over BEEP [RFC4227]
passgo-tivoli 627 tcp PassGo Tivoli [John_Rainford_2] [John_Rainford_2]
passgo-tivoli 627 udp PassGo Tivoli [John_Rainford_2] [John_Rainford_2]
811-827 Unassigned
exp1 1021 tcp RFC3692-style Experiment 1 [IESG] [IETF_Chair] [1][RFC4727][RFC6335]
exp1 1021 udp RFC3692-style Experiment 1 [IESG] [IETF_Chair] [1][RFC4727][RFC6335]
exp1 1021 sctp RFC3692-style Experiment 1 [IESG] [IETF_Chair] [1][RFC4727][RFC6335]
exp1 1021 dccp RFC3692-style Experiment 1 [IESG] [IETF_Chair] [1][RFC4727][RFC6335]
exp2 1022 tcp RFC3692-style Experiment 2 [IESG] [IETF_Chair] [1][RFC4727][RFC6335]
exp2 1022 udp RFC3692-style Experiment 2 [IESG] [IETF_Chair] [1][RFC4727][RFC6335]
exp2 1022 sctp RFC3692-style Experiment 2 [IESG] [IETF_Chair] [1][RFC4727][RFC6335]
exp2 1022 dccp RFC3692-style Experiment 2 [IESG] [IETF_Chair] [1][RFC4727][RFC6335]
6a44 1027 udp IPv6 Behind NAT44 CPEs [IESG] [IETF_Chair] 2012-08-02 [RFC6751]
1027 tcp Reserved
kwdb-commn 1127 tcp KWDB Remote Communication [Lal_Samuel_Varghese] [Lal_Samuel_Varghese] 2005-08
kwdb-commn 1127 udp KWDB Remote Communication [Lal_Samuel_Varghese] [Lal_Samuel_Varghese] 2005-08
dns2go 1227 tcp DNS2Go [Deerfield_Communications_Inc] [Mike_Courterier] 2015-07-15
dns2go 1227 udp DNS2Go [Deerfield_Communications_Inc] [Mike_Courterier] 2015-07-15
opsmgr 1270 tcp Microsoft Operations Manager [Ashvin_Sanghvi] [Ashvin_Sanghvi]
opsmgr 1270 udp Microsoft Operations Manager [Ashvin_Sanghvi] [Ashvin_Sanghvi]
excw 1271 tcp eXcW [Norm_Freedman] [Norm_Freedman]
excw 1271 udp eXcW [Norm_Freedman] [Norm_Freedman]
cspmlockmgr 1272 tcp CSPMLockMgr [Ibtsam_Mahfouz] [Ibtsam_Mahfouz]
cspmlockmgr 1272 udp CSPMLockMgr [Ibtsam_Mahfouz] [Ibtsam_Mahfouz]
emc-gateway 1273 tcp EMC-Gateway [Rene_Fontaine] [Rene_Fontaine]
emc-gateway 1273 udp EMC-Gateway [Rene_Fontaine] [Rene_Fontaine]
t1distproc 1274 tcp t1distproc [Julian_Biddle] [Julian_Biddle]
t1distproc 1274 udp t1distproc [Julian_Biddle] [Julian_Biddle]
ivcollector 1275 tcp ivcollector
ivcollector 1275 udp ivcollector
1276 tcp Reserved 2014-05-23 This entry has been removed on 2014-05-23.
1276 udp Reserved 2014-05-23 This entry has been removed on 2014-05-23.
miva-mqs 1277 tcp mqs [Miva_Corporation] [Miva_Corporation]
miva-mqs 1277 udp mqs [Miva_Corporation] [Miva_Corporation]
dellwebadmin-1 1278 tcp Dell Web Admin 1 [Bridget_Navoda] [Bridget_Navoda]
dellwebadmin-1 1278 udp Dell Web Admin 1 [Bridget_Navoda] [Bridget_Navoda]
dellwebadmin-2 1279 tcp Dell Web Admin 2 [Bridget_Navoda] [Bridget_Navoda]
dellwebadmin-2 1279 udp Dell Web Admin 2 [Bridget_Navoda] [Bridget_Navoda]
ultrex 1327 tcp Ultrex [Tim_Walsh] [Tim_Walsh]
ultrex 1327 udp Ultrex [Tim_Walsh] [Tim_Walsh]
mloadd 1427 tcp mloadd monitoring tool [Bob_Braden_2] [Bob_Braden_2]
mloadd 1427 udp mloadd monitoring tool [Bob_Braden_2] [Bob_Braden_2]
tlisrv 1527 tcp oracle
tlisrv 1527 udp oracle
t128-gateway 1627 tcp T.128 Gateway [Phil_May] [Phil_May]
t128-gateway 1627 udp T.128 Gateway [Phil_May] [Phil_May]
winddx 1727 tcp winddx [Bill_Andrews] [Bill_Andrews]
winddx 1727 udp winddx [Bill_Andrews] [Bill_Andrews]
asi 1827 tcp ASI [Bob_Tournoux] [Bob_Tournoux]
asi 1827 udp ASI [Bob_Tournoux] [Bob_Tournoux]
videte-cipc 1927 tcp Videte CIPC Port [Videte_IT] [Videte_IT]
videte-cipc 1927 udp Videte CIPC Port [Videte_IT] [Videte_IT]
shadowserver 2027 tcp
shadowserver 2027 udp
index-pc-wb 2127 tcp INDEX-PC-WB [James_David_Fisher] [James_David_Fisher]
index-pc-wb 2127 udp INDEX-PC-WB [James_David_Fisher] [James_David_Fisher]
di-msg 2227 tcp DI Messaging Service [Sean_Ni] [Sean_Ni] 2006-02
di-msg 2227 udp DI Messaging Service [Sean_Ni] [Sean_Ni] 2006-02
starschool 2270 tcp starSchool [Adam_Ernst] [Adam_Ernst] 2004-12
starschool 2270 udp starSchool [Adam_Ernst] [Adam_Ernst] 2004-12
mmcals 2271 tcp Secure Meeting Maker Scheduling
mmcals 2271 udp Secure Meeting Maker Scheduling
mmcal 2272 tcp Meeting Maker Scheduling [Andrew_H_Derbyshire] [Andrew_H_Derbyshire] 2004-12
mmcal 2272 udp Meeting Maker Scheduling [Andrew_H_Derbyshire] [Andrew_H_Derbyshire] 2004-12
mysql-im 2273 tcp MySQL Instance Manager [Petr_Chardin] [Petr_Chardin] 2004-12
mysql-im 2273 udp MySQL Instance Manager [Petr_Chardin] [Petr_Chardin] 2004-12
pcttunnell 2274 tcp PCTTunneller [ProControl_Technolog] [ProControl_Technolog] 2004-12
pcttunnell 2274 udp PCTTunneller [ProControl_Technolog] [ProControl_Technolog] 2004-12
ibridge-data 2275 tcp iBridge Conferencing
ibridge-data 2275 udp iBridge Conferencing
ibridge-mgmt 2276 tcp iBridge Management [Patrick_Fisher] [Patrick_Fisher] 2004-12
ibridge-mgmt 2276 udp iBridge Management [Patrick_Fisher] [Patrick_Fisher] 2004-12
bluectrlproxy 2277 tcp Bt device control proxy [Mark_de_Rooi] [Mark_de_Rooi] 2004-12
bluectrlproxy 2277 udp Bt device control proxy [Mark_de_Rooi] [Mark_de_Rooi] 2004-12
s3db 2278 tcp Simple Stacked Sequences Database [David_Brandon] [David_Brandon] 2006-08
s3db 2278 udp Simple Stacked Sequences Database [David_Brandon] [David_Brandon] 2006-08
xmquery 2279 tcp xmquery [Niels_Christiansen] [Niels_Christiansen]
xmquery 2279 udp xmquery [Niels_Christiansen] [Niels_Christiansen]
ansysli 2325 tcp ANSYS Licensing Interconnect [Suzanne_Lorrin] [Suzanne_Lorrin] Modified: 27 October 2008
ansysli 2325 udp ANSYS Licensing Interconnect [Suzanne_Lorrin] [Suzanne_Lorrin] Modified: 27 October 2008
xingcsm 2327 tcp xingcsm [Dave_Spencer] [Dave_Spencer]
xingcsm 2327 udp xingcsm [Dave_Spencer] [Dave_Spencer]
mgcp-gateway 2427 tcp Media Gateway Control Protocol Gateway [Christian_Huitema] [Christian_Huitema]
mgcp-gateway 2427 udp Media Gateway Control Protocol Gateway [Christian_Huitema] [Christian_Huitema]

Contact Information

ID Name Organization Contact URI Last Updated
[Adam_Ernst] Adam Ernst mailto:cosmicsoft&cosmicsoft.net 2004-12
[Andrew_H_Derbyshire] Andrew H Derbyshire mailto:ahd&meetingmaker.plus.kew.com 2004-12
[Ashvin_Sanghvi] Ashvin Sanghvi mailto:AshvinS&microsoft.com
[Bill_Andrews] Bill Andrews mailto:billa&vnd.tek.com
[Bob_Braden_2] Bob Braden mailto:braden&isi.edu
[Bob_Tournoux] Bob Tournoux mailto:bob.tournoux&usiny.mail.abb.com
[Bridget_Navoda] Bridget Navoda mailto:Bridget_Navoda&dell.com
[Christian_Huitema] Christian Huitema mailto:huitema&research.telcordia.com
[Dave_Spencer] Dave Spencer mailto:dspencer&xingtech.com
[David_Brandon] David Brandon mailto:dade&smoolabs.net 2006-08
[Deerfield_Communications_Inc] Deerfield Communications Inc. mailto:mikec&deerfield.net 2015-07-15
[Eric_Peterson] Eric Peterson mailto:lcc.eric&seas.ucla.edu
[Ferdi_Ladeira] Ferdi Ladeira mailto:f.lad.mail&gmail.com 2022-01-25
[IESG] IESG mailto:iesg&ietf.org
[IETF_Chair] IETF Chair IETF mailto:chair&ietf.org
[Ibtsam_Mahfouz] Ibtsam Mahfouz mailto:imahfouz&cisco.com
[James_David_Fisher] James David Fisher mailto:jfisher1&avaya.com
[John_Rainford_2] John Rainford mailto:john.rainford&passgo.com
[Julian_Biddle] Julian Biddle mailto:julian_biddle&technologyonecorp.com
[Lal_Samuel_Varghese] Lal Samuel Varghese mailto:lalsam&hp.com 2005-08
[Mark_de_Rooi] Mark de Rooi mailto:derooi&xs4all.nl 2004-12
[Mike_Courterier] Mike Courterier Deerfield Communications Inc. mailto:mikec&deerfield.net 2015-07-15
[Miva_Corporation] Miva Corporation mailto:jwoods&miva.com.au
[Niels_Christiansen] Niels Christiansen mailto:nchris&austin.ibm.com
[Norm_Freedman] Norm Freedman mailto:normfree&san.rr.com 2003-08
[Patrick_Fisher] Patrick Fisher mailto:pfisher&hns.com 2004-12
[Petr_Chardin] Petr Chardin mailto:petr&mysql.com 2004-12
[Phil_May] Phil May mailto:pm&datcon.co.uk
[ProControl_Technolog] ProControl Technology AB mailto:info&pctworld.com 2004-12
[Rene_Fontaine] Rene Fontaine mailto:fontaine_rene&emc.com
[Robert_Thomas] Robert Thomas mailto:BThomas&f.bbn.com
[Sean_Ni] Sean Ni mailto:seanni&digitalinstinct.com.tw 2006-02
[Suzanne_Lorrin] Suzanne Lorrin mailto:suzanne.lorrin&ansys.com
[Tim_Walsh] Tim Walsh mailto:tim&ultrex.com
[Veizades] mailto:veizades&ftp.com
[Videte_IT] Videte IT mailto:info&videte.com
[Weldon_J_Showalter] Weldon J. Showalter mailto:Gamma&mintaka.dca.mil