Service Name and Transport Protocol Port Number Registry

Last Updated
2026-03-27
Expert(s)
TCP/UDP: Joe Touch; Eliot Lear, Kumiko Ono, Wes Eddy, Brian Trammell, 
Jana Iyengar, 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
0 tcp Reserved 2024-12-20 [RFC6335]
0 udp Reserved 2024-12-20 [RFC6335]
dsp 33 tcp Display Support Protocol [Ed_Cain] [Ed_Cain]
dsp 33 udp Display Support Protocol [Ed_Cain] [Ed_Cain]
statsrv 133 tcp Statistics Service [Dave_Mills_2] [Dave_Mills_2]
statsrv 133 udp Statistics Service [Dave_Mills_2] [Dave_Mills_2]
325-332 Unassigned
texar 333 tcp Texar Security Port [Eugen_Bacic] [Eugen_Bacic]
texar 333 udp Texar Security Port [Eugen_Bacic] [Eugen_Bacic]
334-343 Unassigned
nnsp 433 tcp NNTP for transit servers (NNSP) [IESG] [IETF_Chair] 2018-07-06 [RFC3977]
nnsp 433 udp NNTP for transit servers (NNSP) [IESG] [IETF_Chair] 2018-07-06 [RFC3977]
netwall 533 tcp for emergency broadcasts [Andreas_Heidemann] [Andreas_Heidemann]
netwall 533 udp for emergency broadcasts [Andreas_Heidemann] [Andreas_Heidemann]
servstat 633 tcp Service Status update (Sterling Software) [Greg_Rose] [Greg_Rose]
servstat 633 udp Service Status update (Sterling Software) [Greg_Rose] [Greg_Rose]
833 tcp Reserved 2025-09-29 Previously assigned to NETCONF over SOAP but released by [RFC9900]
833 udp Reserved 2025-09-29 Previously assigned to NETCONF over SOAP but released by [RFC9900]
apex-edge 913 tcp APEX endpoint-relay service [RFC3340]
apex-edge 913 udp APEX endpoint-relay service [RFC3340]
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]
1023 tcp Reserved 2024-12-20 [RFC6335]
1023 udp Reserved 2024-12-20 [RFC6335]
1024 tcp Reserved 2024-12-20 [RFC6335]
1024 udp Reserved 2024-12-20 [RFC6335]
netinfo-local 1033 tcp local netinfo port [Marc_Majka] [Marc_Majka] 2002-08
netinfo-local 1033 udp local netinfo port [Marc_Majka] [Marc_Majka] 2002-08
dfn 1133 tcp Data Flow Network [Mikhailov_Center] [Anton_Mikhailov] 2006-02 2021-03-04
dfn 1133 udp Data Flow Network [Mikhailov_Center] [Anton_Mikhailov] 2006-02 2021-03-04
univ-appserver 1233 tcp Universal App Server [Tim_Sent] [Tim_Sent]
univ-appserver 1233 udp Universal App Server [Tim_Sent] [Tim_Sent]
streetperfect 1330 tcp StreetPerfect [Michael_R_Young] [Michael_R_Young]
streetperfect 1330 udp StreetPerfect [Michael_R_Young] [Michael_R_Young]
intersan 1331 tcp intersan [Barry_H_Feild] [Barry_H_Feild]
intersan 1331 udp intersan [Barry_H_Feild] [Barry_H_Feild]
pcia-rxp-b 1332 tcp PCIA RXP-B [James_Dabbs] [James_Dabbs]
pcia-rxp-b 1332 udp PCIA RXP-B [James_Dabbs] [James_Dabbs]
passwrd-policy 1333 tcp Password Policy [Tonio_Pirotta] [Tonio_Pirotta]
passwrd-policy 1333 udp Password Policy [Tonio_Pirotta] [Tonio_Pirotta]
writesrv 1334 tcp writesrv [Marvin_Toungate] [Marvin_Toungate]
writesrv 1334 udp writesrv [Marvin_Toungate] [Marvin_Toungate]
digital-notary 1335 tcp Digital Notary Protocol [Wes_Doonan] [Wes_Doonan]
digital-notary 1335 udp Digital Notary Protocol [Wes_Doonan] [Wes_Doonan]
ischat 1336 tcp Instant Service Chat [Mike_Clise] [Mike_Clise]
ischat 1336 udp Instant Service Chat [Mike_Clise] [Mike_Clise]
menandmice-dns 1337 tcp menandmice DNS [Sigfus_Magnusson] [Sigfus_Magnusson]
menandmice-dns 1337 udp menandmice DNS [Sigfus_Magnusson] [Sigfus_Magnusson]
wmc-log-svc 1338 tcp WMC-log-svr [Scott_Anderson] [Scott_Anderson]
wmc-log-svc 1338 udp WMC-log-svr [Scott_Anderson] [Scott_Anderson]
kjtsiteserver 1339 tcp kjtsiteserver [Jason_Aubain] [Jason_Aubain]
kjtsiteserver 1339 udp kjtsiteserver [Jason_Aubain] [Jason_Aubain]
ms-sql-s 1433 tcp Microsoft-SQL-Server
ms-sql-s 1433 udp Microsoft-SQL-Server
virtual-places 1533 tcp Virtual Places Software [Avshalom_Houri] [Avshalom_Houri]
virtual-places 1533 udp Virtual Places Software [Avshalom_Houri] [Avshalom_Houri]
pammrpc 1633 tcp PAMMRPC [John_Britton] [John_Britton]
pammrpc 1633 udp PAMMRPC [John_Britton] [John_Britton]
siipat 1733 tcp SIMS - SIIPAT Protocol for Alarm Transmission [Steve_Ryckman] [Steve_Ryckman]
siipat 1733 udp SIMS - SIIPAT Protocol for Alarm Transmission [Steve_Ryckman] [Steve_Ryckman]
udpradio 1833 tcp udpradio [Guus_Sliepen] [Guus_Sliepen]
udpradio 1833 udp udpradio [Guus_Sliepen] [Guus_Sliepen]
xmapi 1933 tcp IBM LM MT Agent
xmapi 1933 udp IBM LM MT Agent
glogger 2033 tcp
glogger 2033 udp
zymed-zpp 2133 tcp ZYMED-ZPP [Gregg_Welker] [Gregg_Welker]
zymed-zpp 2133 udp ZYMED-ZPP [Gregg_Welker] [Gregg_Welker]
infocrypt 2233 tcp INFOCRYPT [Erica_Liu] [Erica_Liu]
infocrypt 2233 udp INFOCRYPT [Erica_Liu] [Erica_Liu]
tscchat 2330 tcp TSCCHAT [Mike_Jackson] [Mike_Jackson]
tscchat 2330 udp TSCCHAT [Mike_Jackson] [Mike_Jackson]
agentview 2331 tcp AGENTVIEW [Ram_Iyer] [Ram_Iyer]
agentview 2331 udp AGENTVIEW [Ram_Iyer] [Ram_Iyer]
rcc-host 2332 tcp RCC Host [Martin_Shoemaker] [Martin_Shoemaker]
rcc-host 2332 udp RCC Host [Martin_Shoemaker] [Martin_Shoemaker]
snapp 2333 tcp SNAPP [Dan_Burrows] [Dan_Burrows] 2009-09-25
snapp 2333 udp SNAPP [Dan_Burrows] [Dan_Burrows] 2009-09-25
ace-client 2334 tcp ACE Client Auth
ace-client 2334 udp ACE Client Auth
ace-proxy 2335 tcp ACE Proxy [Riaz_Zolfonoon] [Riaz_Zolfonoon]
ace-proxy 2335 udp ACE Proxy [Riaz_Zolfonoon] [Riaz_Zolfonoon]
appleugcontrol 2336 tcp Apple UG Control [Gene_Tyacke] [Gene_Tyacke]
appleugcontrol 2336 udp Apple UG Control [Gene_Tyacke] [Gene_Tyacke]
ideesrv 2337 tcp ideesrv [Marazzi] [Marazzi]
ideesrv 2337 udp ideesrv [Marazzi] [Marazzi]
norton-lambert 2338 tcp Norton Lambert [Richard_de_Mornay] [Richard_de_Mornay]
norton-lambert 2338 udp Norton Lambert [Richard_de_Mornay] [Richard_de_Mornay]
3com-webview 2339 tcp 3Com WebView [Jennifer_Grace] [Jennifer_Grace]
3com-webview 2339 udp 3Com WebView [Jennifer_Grace] [Jennifer_Grace]
codasrv-se 2433 tcp codasrv-se [Robert_Watson] [Robert_Watson]
codasrv-se 2433 udp codasrv-se [Robert_Watson] [Robert_Watson]
snifferserver 2533 tcp SnifferServer [Amy_Weaver_3] [Amy_Weaver_3]
snifferserver 2533 udp SnifferServer [Amy_Weaver_3] [Amy_Weaver_3]

Contact Information

ID Name Organization Contact URI Last Updated
[Amy_Weaver_3] Amy Weaver mailto:Amy_Weaver&nai.com
[Andreas_Heidemann] Andreas Heidemann mailto:a.heidemann&ais-gmbh.de
[Anton_Mikhailov] Anton Mikhailov Mikhailov Center mailto:anton&mikhailov.center 2021-03-04
[Avshalom_Houri] Avshalom Houri mailto:Avshalom&ubique.com
[Barry_H_Feild] Barry H. Feild mailto:barry&intersan.net
[Dan_Burrows] Dan Burrows mailto:dburrows&overlandstorage.com 2009-09-25
[Dave_Mills_2] Dave Mills mailto:Mills&huey.udel.edu
[Ed_Cain] Ed Cain mailto:cain&edn-unix.dca.mil
[Erica_Liu] Erica Liu mailto:liue&isolation.com
[Eugen_Bacic] Eugen Bacic mailto:ebacic&texar.com
[Gene_Tyacke] Gene Tyacke mailto:gene&apple.com
[Greg_Rose] Greg Rose mailto:Greg_Rose&sydney.sterling.com
[Gregg_Welker] Gregg Welker mailto:greggw&zmi.com
[Guus_Sliepen] Guus Sliepen mailto:guus&warande3094.warande.uu.nl
[IESG] IESG mailto:iesg&ietf.org
[IETF_Chair] IETF Chair IETF mailto:chair&ietf.org
[James_Dabbs] James Dabbs mailto:jdabbs&tga.com
[Jason_Aubain] Jason Aubain mailto:jaubain&kjt.com
[Jennifer_Grace] Jennifer Grace mailto:Jennifer_Grace&3com.com
[John_Britton] John Britton mailto:johnb&peakaudio.com
[Marazzi] Marazzi mailto:fmarazzi&ideetique.com
[Marc_Majka] Marc Majka mailto:majka&apple.com 2002-08
[Martin_Shoemaker] Martin Shoemaker mailto:shoemakerml&rapistan.com
[Marvin_Toungate] Marvin Toungate mailto:toungate&austin.ibm.com
[Michael_R_Young] Michael R. Young mailto:michael.young&streetperfect.com 2019-02-15
[Mike_Clise] Mike Clise mailto:mikec&instantservice.com
[Mike_Jackson] Mike Jackson mailto:mhjack&tscnet.com
[Mikhailov_Center] Mikhailov Center mailto:pulse.cc&mail.ru 2021-03-04
[Ram_Iyer] Ram Iyer mailto:ram&aaccorp.com
[Riaz_Zolfonoon] Riaz Zolfonoon mailto:rzolfonoon&securitydynamics.com
[Richard_de_Mornay] Richard de Mornay mailto:rdemornay&norton-lambert.com
[Robert_Watson] Robert Watson mailto:robert&cyrus.watson.org
[Scott_Anderson] Scott Anderson mailto:sanderso&workingmachines.com
[Sigfus_Magnusson] Sigfus Magnusson mailto:sigfusm&menandmice.com
[Steve_Ryckman] Steve Ryckman mailto:iana&simsware.com
[Tim_Sent] Tim Sent mailto:tim.sent&systemsarchitects.com
[Tonio_Pirotta] Tonio Pirotta mailto:tonio&tpis.com.au
[Wes_Doonan] Wes Doonan