draft-ietf-tsvwg-iana-ports-08.txt   draft-ietf-tsvwg-iana-ports-09.txt 
Transport Area Working Group M. Cotton Transport Area Working Group M. Cotton
Internet-Draft ICANN Internet-Draft ICANN
Updates: 2780, 2782, 3828, 4340, L. Eggert Updates: 2780, 2782, 3828, 4340, L. Eggert
4960 (if approved) Nokia 4960 (if approved) Nokia
Intended status: BCP J. Touch Intended status: BCP J. Touch
Expires: April 28, 2011 USC/ISI Expires: June 5, 2011 USC/ISI
M. Westerlund M. Westerlund
Ericsson Ericsson
S. Cheshire S. Cheshire
Apple Apple
October 25, 2010 December 2, 2010
Internet Assigned Numbers Authority (IANA) Procedures for the Management Internet Assigned Numbers Authority (IANA) Procedures for the Management
of the Service Name and Transport Protocol Port Number Registry of the Service Name and Transport Protocol Port Number Registry
draft-ietf-tsvwg-iana-ports-08 draft-ietf-tsvwg-iana-ports-09
Abstract Abstract
This document defines the procedures that the Internet Assigned This document defines the procedures that the Internet Assigned
Numbers Authority (IANA) uses when handling registration and other Numbers Authority (IANA) uses when handling assignment and other
requests related to the Service Name and Transport Protocol Port requests related to the Service Name and Transport Protocol Port
Number Registry. It also discusses the rationale and principles Number Registry. It also discusses the rationale and principles
behind these procedures and how they facilitate the long-term behind these procedures and how they facilitate the long-term
sustainability of the registry. sustainability of the registry.
This document updates IANA's procedures by obsoleting Sections 8 and This document updates IANA's procedures by obsoleting the previous
9.1 of the IANA allocation guidelines [RFC2780], and it updates the UDP and TCP port assignment procedures defined in Sections 8 and 9.1
IANA allocation procedures for UDP-Lite [RFC3828], DCCP [RFC4340] and of the IANA allocation guidelines [RFC2780], and it updates the IANA
SCTP [RFC4960]. It also updates the DNS SRV specification [RFC2782] Service Name and Port assignment procedures for UDP-Lite [RFC3828],
to clarify what a service name is and how it is registered. DCCP [RFC4340] and SCTP [RFC4960]. It also updates the DNS SRV
specification [RFC2782] to clarify what a service name is and how it
is registered.
Status of this Memo Status of this Memo
This Internet-Draft is submitted in full conformance with the This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79. provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet- working documents as Internet-Drafts. The list of current Internet-
Drafts is at http://datatracker.ietf.org/drafts/current/. Drafts is at http://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress." material or to cite them other than as "work in progress."
This Internet-Draft will expire on June 5, 2011.
This Internet-Draft will expire on April 28, 2011.
Copyright Notice Copyright Notice
Copyright (c) 2010 IETF Trust and the persons identified as the Copyright (c) 2010 IETF Trust and the persons identified as the
document authors. All rights reserved. document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents Provisions Relating to IETF Documents
(http://trustee.ietf.org/license-info) in effect on the date of (http://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents publication of this document. Please review these documents
skipping to change at page 3, line 14 skipping to change at page 3, line 14
Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 4 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 4
2. Motivation . . . . . . . . . . . . . . . . . . . . . . . . . . 5 2. Motivation . . . . . . . . . . . . . . . . . . . . . . . . . . 5
3. Background . . . . . . . . . . . . . . . . . . . . . . . . . . 6 3. Background . . . . . . . . . . . . . . . . . . . . . . . . . . 6
4. Conventions Used in this Document . . . . . . . . . . . . . . 7 4. Conventions Used in this Document . . . . . . . . . . . . . . 7
5. Service Names . . . . . . . . . . . . . . . . . . . . . . . . 8 5. Service Names . . . . . . . . . . . . . . . . . . . . . . . . 8
5.1. Service Name Syntax . . . . . . . . . . . . . . . . . . . 9 5.1. Service Name Syntax . . . . . . . . . . . . . . . . . . . 9
5.2. Service Name Usage in DNS SRV Records . . . . . . . . . . 10 5.2. Service Name Usage in DNS SRV Records . . . . . . . . . . 10
6. Port Number Ranges . . . . . . . . . . . . . . . . . . . . . . 10 6. Port Number Ranges . . . . . . . . . . . . . . . . . . . . . . 11
6.1. Service names and Port Numbers for Experimentation . . . . 11 6.1. Service names and Port Numbers for Experimentation . . . . 11
7. Principles for Service Name and Transport Protocol Port 7. Principles for Service Name and Transport Protocol Port
Number Registry Management . . . . . . . . . . . . . . . . . . 12 Number Registry Management . . . . . . . . . . . . . . . . . . 12
7.1. Past Principles . . . . . . . . . . . . . . . . . . . . . 12 7.1. Past Principles . . . . . . . . . . . . . . . . . . . . . 12
7.2. Updated Principles . . . . . . . . . . . . . . . . . . . . 13 7.2. Updated Principles . . . . . . . . . . . . . . . . . . . . 13
8. IANA Procedures for Managing the Service Name and 8. IANA Procedures for Managing the Service Name and
Transport Protocol Port Number Registry . . . . . . . . . . . 15 Transport Protocol Port Number Registry . . . . . . . . . . . 16
8.1. Service Name and Port Number Registration . . . . . . . . 16 8.1. Service Name and Port Number Assignment . . . . . . . . . 16
8.2. Service Name and Port Number De-Registration . . . . . . . 20 8.2. Service Name and Port Number De-Assignment . . . . . . . . 20
8.3. Service Name and Port Number Re-Use . . . . . . . . . . . 20 8.3. Service Name and Port Number Reuse . . . . . . . . . . . . 20
8.4. Service Name and Port Number Revocation . . . . . . . . . 21 8.4. Service Name and Port Number Revocation . . . . . . . . . 21
8.5. Service Name and Port Number Transfers . . . . . . . . . . 21 8.5. Service Name and Port Number Transfers . . . . . . . . . . 21
8.6. Maintenance Issues . . . . . . . . . . . . . . . . . . . . 22 8.6. Maintenance Issues . . . . . . . . . . . . . . . . . . . . 22
8.7. Disagreements . . . . . . . . . . . . . . . . . . . . . . 22 8.7. Disagreements . . . . . . . . . . . . . . . . . . . . . . 22
9. Security Considerations . . . . . . . . . . . . . . . . . . . 22 9. Security Considerations . . . . . . . . . . . . . . . . . . . 22
10. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 22 10. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 22
10.1. Service Name Consistency . . . . . . . . . . . . . . . . . 23 10.1. Service Name Consistency . . . . . . . . . . . . . . . . . 23
10.2. Port Numbers for SCTP and DCCP Experimentation . . . . . . 25 10.2. Port Numbers for SCTP and DCCP Experimentation . . . . . . 24
10.3. Updates to DCCP Registries . . . . . . . . . . . . . . . . 26 10.3. Updates to DCCP Registries . . . . . . . . . . . . . . . . 25
11. Contributors . . . . . . . . . . . . . . . . . . . . . . . . . 27 11. Contributors . . . . . . . . . . . . . . . . . . . . . . . . . 26
12. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 27 12. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 27
13. References . . . . . . . . . . . . . . . . . . . . . . . . . . 28 13. References . . . . . . . . . . . . . . . . . . . . . . . . . . 27
13.1. Normative References . . . . . . . . . . . . . . . . . . . 28 13.1. Normative References . . . . . . . . . . . . . . . . . . . 27
13.2. Informative References . . . . . . . . . . . . . . . . . . 29 13.2. Informative References . . . . . . . . . . . . . . . . . . 28
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 30 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 29
1. Introduction 1. Introduction
For many years, the allocation of new service names and port number For many years, the assignment of new service names and port number
values for use with the Transmission Control Protocol (TCP) [RFC0793] values for use with the Transmission Control Protocol (TCP) [RFC0793]
and the User Datagram Protocol (UDP) [RFC0768] have had less than and the User Datagram Protocol (UDP) [RFC0768] have had less than
clear guidelines. New transport protocols have been added - the clear guidelines. New transport protocols have been added - the
Stream Control Transmission Protocol (SCTP) [RFC4960] and the Stream Control Transmission Protocol (SCTP) [RFC4960] and the
Datagram Congestion Control Protocol (DCCP) [RFC4342] - and new Datagram Congestion Control Protocol (DCCP) [RFC4342] - and new
mechanisms like DNS SRV records [RFC2782] have been developed, each mechanisms like DNS SRV records [RFC2782] have been developed, each
with separate registries and separate guidelines. The community also with separate registries and separate guidelines. The community also
recognized the need for additional procedures beyond just assignment; recognized the need for additional procedures beyond just assignment;
notably modification, revocation, and release. notably modification, revocation, and release.
A key element of the procedural streamlining specified in this A key element of the procedural streamlining specified in this
document is to establish identical assignment procedures for all IETF document is to establish identical assignment procedures for all IETF
transport protocols. This document brings the IANA procedures for transport protocols. This document brings the IANA procedures for
TCP and UDP in line with those for SCTP and DCCP, resulting in a TCP and UDP in line with those for SCTP and DCCP, resulting in a
single process that requesters and IANA follow for all requests for single process that requesters and IANA follow for all requests for
all transport protocols, including future protocols not yet defined. all transport protocols, including future protocols not yet defined.
In addition to detailing the IANA procedures for the initial In addition to detailing the IANA procedures for the initial
assignment of service names and port numbers, this document also assignment of service names and port numbers, this document also
specifies post-assignment procedures that until now have been handled specifies post-assignment procedures that until now have been handled
in an ad hoc manner. These include procedures to de-register a port in an ad hoc manner. These include procedures to de-assign a port
number that is no longer in use, to re-use a port number allocated number that is no longer in use, to take a port number assigned for
for one application that is no longer in use for another application, one service that is no longer in use and reuse it for another
and the procedure by which IANA can unilaterally revoke a prior port service, and the procedure by which IANA can unilaterally revoke a
number assignment. Section 8 discusses the specifics of these prior port number assignment. Section 8 discusses the specifics of
procedures and processes that requesters and IANA follow for all these procedures and processes that requesters and IANA follow for
requests for all current and future transport protocols. all requests for all current and future transport protocols.
IANA is the authority for assigning service names and port numbers. IANA is the authority for assigning service names and port numbers.
The registries that are created to store these registrations are The registries that are created to store these assignments are
maintained by IANA. For protocols developed by IETF working groups, maintained by IANA. For protocols developed by IETF working groups,
IANA now also offers a method for the "early assignment" [RFC4020] of IANA now also offers a method for the "early assignment" [RFC4020] of
service names and port numbers, as described in Section 8.1. service names and port numbers, as described in Section 8.1.
This document updates IANA's procedures for UDP and TCP port numbers This document updates IANA's procedures for UDP and TCP port numbers
by obsoleting Sections 8 and 9.1 of the IANA allocation guidelines by obsoleting Sections 8 and 9.1 of the IANA assignment guidelines
[RFC2780]. (Note that other sections of the IANA allocation [RFC2780]. (Note that other sections of the IANA assignment
guidelines, relating to the protocol field values in IPv4 header, guidelines, relating to the protocol field values in IPv4 header,
were also updated in February 2008 [RFC5237].) This document also were also updated in February 2008 [RFC5237].) This document also
updates the IANA allocation procedures for DCCP [RFC4340] and SCTP updates the IANA assignment procedures for DCCP [RFC4340] and SCTP
[RFC4960]. [RFC4960].
The Lightweight User Datagram Protocol (UDP-Lite) [RFC5237] shares The Lightweight User Datagram Protocol (UDP-Lite) shares the port
the port space with UDP. The UDP-Lite specification says: "UDP-Lite space with UDP. The UDP-Lite specification [RFC5237] says: "UDP-Lite
uses the same set of port number values assigned by the IANA for use uses the same set of port number values assigned by the IANA for use
by UDP". Thus the update of UDP procedures result in an update also by UDP". Thus the update of UDP procedures result in an update also
of the UDP-Lite procedures. of the UDP-Lite procedures.
This document also clarifies what a service name is and how it is This document also clarifies what a service name is and how it is
registered. This will impact the DNS SRV specification [RFC2782], assigned. This will impact the DNS SRV specification [RFC2782],
because that specification merely makes a brief mention that the because that specification merely makes a brief mention that the
symbolic names of services are defined in "Assigned Numbers" symbolic names of services are defined in "Assigned Numbers"
[RFC1700], without stating to which section it refers within that [RFC1700], without stating to which section it refers within that
230-page document. The DNS SRV specification may have been referring 230-page document. The DNS SRV specification may have been referring
to the list of Port Assignments (known as /etc/services on Unix), or to the list of Port Assignments (known as /etc/services on Unix), or
to the "Protocol And Service Names" section, or to both, or to some to the "Protocol And Service Names" section, or to both, or to some
other section. Furthermore, "Assigned Numbers" is now obsolete other section. Furthermore, "Assigned Numbers" is now obsolete
[RFC3232] and has been replaced by on-line registries [RFC3232] and has been replaced by on-line registries
[PORTREG][PROTSERVREG]. [PORTREG][PROTSERVREG].
The development of new transport protocols is a major effort that the The development of new transport protocols is a major effort that the
IETF does not undertake very often. If a new transport protocol is IETF does not undertake very often. If a new transport protocol is
standardized in the future, for consistency it is expected to follow standardized in the future, it is expected to follow these guidelines
as much as possible the guidelines and practices around using service and practices around using service names and port numbers as much as
names and port numbers. possible, for consistency.
2. Motivation 2. Motivation
Information about the registration procedures for the port registry Information about the assignment procedures for the port registry has
has existed in three locations: the forms for requesting port number existed in three locations: the forms for requesting port number
registrations on the IANA web site [SYSFORM] [USRFORM], an assignments on the IANA web site [SYSFORM][USRFORM], an introductory
introductory text section in the file listing the port number text section in the file listing the port number assignments
registrations themselves [PORTREG], and two brief sections of the themselves (known as the port numbers registry) [PORTREG], and two
IANA Allocation Guidelines [RFC2780]. brief sections of the IANA Allocation Guidelines [RFC2780].
Similarly, the procedures surrounding service names have been Similarly, the procedures surrounding service names have been
historically unclear. Service names were originally created as historically unclear. Service names were originally created as
mnemonic identifiers for port numbers without a well-defined syntax, mnemonic identifiers for port numbers without a well-defined syntax,
beyond the 14-character limit mentioned on the IANA website [SYSFORM] apart from the 14-character limit mentioned on the IANA website
[USRFORM]. Even that length limit has not been consistently applied, [SYSFORM][USRFORM]. Even that length limit has not been consistently
and some assigned service names are 15 characters long. When service applied, and some assigned service names are 15 characters long.
identification via DNS SRV Resource Records (RRs) was introduced, the When service identification via DNS SRV Resource Records (RRs) was
requirement by IANA to only assign service names and port numbers in introduced [RFC2782], it became useful to start assigning service
combination, led to the creation of an ad hoc service name registry names alone, and because IANA had no procedure for assigning a
outside of the control of IANA [SRVREG]. service name without an associated port number, this lead to the
creation of an informal temporary service name registry outside of
the control of IANA, which now contains roughly 500 service names
[SRVREG].
This document aggregates all this scattered information into a single This document aggregates all this scattered information into a single
reference that aligns and clearly defines the management procedures reference that aligns and clearly defines the management procedures
for both service names and port numbers. It gives more detailed for both service names and port numbers. It gives more detailed
guidance to prospective requesters of service names and ports than guidance to prospective requesters of service names and ports than
the existing documentation, and it streamlines the IANA procedures the existing documentation, and it streamlines the IANA procedures
for the management of the registry, so that requests can be completed for the management of the registry, so that requests can be completed
in a timely manner. in a timely manner.
This document defines rules for registration of service names without This document defines rules for assignment of service names without
associated port numbers, for such usages as DNS SRV records associated port numbers, for such usages as DNS SRV records
[RFC2782], which was not possible under the previous IANA procedures. [RFC2782], which was not possible under the previous IANA procedures.
The document also merges service name registrations from the non-IANA The document also merges service name assignments from the non-IANA
ad hoc registry [SRVREG] and from the IANA "Protocol and Service ad hoc registry [SRVREG] and from the IANA "Protocol and Service
Names" registry [PROTSERVREG] into the IANA "Service Name and Names" registry [PROTSERVREG] into the IANA "Service Name and
Transport Protocol Port Number" registry [PORTREG], which from here Transport Protocol Port Number" registry [PORTREG], which from here
on is the single authoritative registry for service names and port on is the single authoritative registry for service names and port
numbers. numbers.
An additional purpose of this document is to describe the principles An additional purpose of this document is to describe the principles
that guide the IETF and IANA in their role as the long-term joint that guide the IETF and IANA in their role as the long-term joint
stewards of the service name and port number registry. TCP and UDP stewards of the service name and port number registry. TCP and UDP
have had remarkable success over the last decades. Thousands of have had remarkable success over the last decades. Thousands of
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3. Background 3. Background
The Transmission Control Protocol (TCP) [RFC0793] and the User The Transmission Control Protocol (TCP) [RFC0793] and the User
Datagram Protocol (UDP) [RFC0768] have enjoyed a remarkable success Datagram Protocol (UDP) [RFC0768] have enjoyed a remarkable success
over the decades as the two most widely used transport protocols on over the decades as the two most widely used transport protocols on
the Internet. They have relied on the concept of "ports" as logical the Internet. They have relied on the concept of "ports" as logical
entities for Internet communication. Ports serve two purposes: entities for Internet communication. Ports serve two purposes:
first, they provide a demultiplexing identifier to differentiate first, they provide a demultiplexing identifier to differentiate
transport sessions between the same pair of endpoints, and second, transport sessions between the same pair of endpoints, and second,
they may also identify the application protocol and associated they may also identify the application protocol and associated
service to which processes bind. Newer transport protocols, such as service to which processes connect. Newer transport protocols, such
the Stream Control Transmission Protocol (SCTP) [RFC4960] and the as the Stream Control Transmission Protocol (SCTP) [RFC4960] and the
Datagram Congestion Control Protocol (DCCP) [RFC4342] have also Datagram Congestion Control Protocol (DCCP) [RFC4342] have also
adopted the concept of ports for their communication sessions and use adopted the concept of ports for their communication sessions and use
16-bit port numbers in the same way as TCP and UDP (and UDP-Lite 16-bit port numbers in the same way as TCP and UDP (and UDP-Lite
[RFC3828], a variant of UDP). [RFC3828], a variant of UDP).
Port numbers are the original and most widely used means for Port numbers are the original and most widely used means for
application and service identification on the Internet. Ports are application and service identification on the Internet. Ports are
16-bit numbers, and the combination of source and destination port 16-bit numbers, and the combination of source and destination port
numbers together with the IP addresses of the communicating end numbers together with the IP addresses of the communicating end
systems uniquely identifies a session of a given transport protocol. systems uniquely identifies a session of a given transport protocol.
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implies a particular service may become less true. For example, implies a particular service may become less true. For example,
multiple instances of the same service on the same host cannot multiple instances of the same service on the same host cannot
generally listen on the same port, and multiple hosts behind the same generally listen on the same port, and multiple hosts behind the same
NAT gateway cannot all have a mapping for the same port on the NAT gateway cannot all have a mapping for the same port on the
external side of the NAT gateway, whether using static port mappings external side of the NAT gateway, whether using static port mappings
configured by hand by the user, or dynamic port mappings configured configured by hand by the user, or dynamic port mappings configured
automatically using a port mapping protocol like NAT Port Mapping automatically using a port mapping protocol like NAT Port Mapping
Protocol (NAT-PMP) [I-D.cheshire-nat-pmp] or Internet Gateway Device Protocol (NAT-PMP) [I-D.cheshire-nat-pmp] or Internet Gateway Device
(IGD) [IGD]. (IGD) [IGD].
Applications may use numeric port numbers directly, look up port Applications may use port numbers directly, look up port numbers
numbers based on service names via system calls such as based on service names via system calls such as getservbyname() on
getservbyname() on UNIX, look up port numbers by performing queries UNIX, look up port numbers by performing queries for DNS SRV records
for DNS SRV records [RFC2782][I-D.cheshire-dnsext-dns-sd], or [RFC2782][I-D.cheshire-dnsext-dns-sd], or determine port numbers in a
determine port numbers in a variety of other ways like the TCP Port variety of other ways like the TCP Port Service Multiplexer (TCPMUX)
Service Multiplexer (TCPMUX) [RFC1078]. [RFC1078].
Designers of applications and application-level protocols may apply Designers of applications and application-level protocols may apply
to IANA for an assigned service name and port number for a specific to IANA for an assigned service name and port number for a specific
application, and may - after successful registration - assume that no application, and may - after assignment - assume that no other
other application will use that service name or port number for its application will use that service name or port number for its
communication sessions. Alternatively, application designers may communication sessions. Alternatively, application designers may
also ask for only an assigned service name, if their application does also ask for only an assigned service name, if their application does
not require a fixed port number. The latter alternative is not require a fixed port number. The latter alternative is
encouraged when possible, in order to conserve the more limited port encouraged when possible, in order to conserve the more limited port
number space. This is applicable, for example, to applications that number space. This is applicable, for example, to applications that
use DNS SRV records to look up port numbers at runtime. use DNS SRV records to look up port numbers at runtime.
4. Conventions Used in this Document 4. Conventions Used in this Document
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in "Key words for use in document are to be interpreted as described in "Key words for use in
RFCs to Indicate Requirement Levels" [RFC2119]. RFCs to Indicate Requirement Levels" [RFC2119].
This document uses the term "assignment" to refer to the procedure by
which IANA provides service names and/or port numbers to requesting
parties; other RFCs refer to this as "allocation" or "registration".
This document assumes that all these terms have the same meaning, and
will use terms other than "assignment" when quoting from or referring
to text in these other documents.
5. Service Names 5. Service Names
Service names are the unique key in the Service Name and Transport Service names are the unique key in the Service Name and Transport
Protocol Port Number Registry. This unique symbolic name for a Protocol Port Number Registry. This unique symbolic name for a
service may also be used for other purposes, such as in DNS SRV service may also be used for other purposes, such as in DNS SRV
records [RFC2782]. Within the registry, this unique key ensures that records [RFC2782]. Within the registry, this unique key ensures that
different services can be unambiguously distinguished, thus different services can be unambiguously distinguished, thus
preventing name collisions and avoiding confusion about who is the preventing name collisions and avoiding confusion about who is the
Registrant for a particular entry. Assignee for a particular entry.
There may be more than one service name associated with a particular There may be more than one service name associated with a particular
transport protocol and port. There are three ways that such service transport protocol and port. There are three ways that such port
name overloading can occur: number overloading can occur:
o Overloading occurs when one service is an extension of another o Overloading occurs when one service is an extension of another
service, and an in-band mechanism exists for determining if the service, and an in-band mechanism exists for determining if the
extension is present or not. One example is port 3478, which has extension is present or not. One example is port 3478, which has
the service name aliases "stun" and "turn". TURN [RFC5766] is an the service name aliases "stun" and "turn". TURN [RFC5766] is an
extension to the STUN [RFC5389] service. TURN-enabled clients extension to the STUN [RFC5389] service. TURN-enabled clients
wishing to locate TURN servers could attempt to discover "stun" wishing to locate TURN servers could attempt to discover "stun"
services and then check in-band if the server supports TURN, but services and then check in-band if the server also supports TURN,
this would be inefficient. Enabling them to directly query for but this would be inefficient. Enabling them to directly query
"turn" servers by name is a better approach. (Note that TURN for "turn" servers by name is a better approach. (Note that TURN
servers in this case should also be locatable via a "stun" servers in this case should also be locatable via a "stun"
discovery, because every TURN server is also a STUN server.) discovery, because every TURN server is also a STUN server.)
o By historical accident the service name "http" corresponds to the o By historical accident, the service name "http" has two synonyms
same port number as "www" and "www-http". When used in SRV "www" and "www-http". When used in SRV records [RFC2782] and
records [RFC2782], and similar service discovery mechanisms only similar service discovery mechanisms, only the service name "http"
the service name "http" should be used, not these additional should be used, not these additional names. If a server were to
names. If a server were to advertise "www" then it would not be advertise "www", it would not be discovered by clients browsing
discovered by clients browsing for "http". Advertising or for "http". Advertising or browsing for the aliases as well as
browsing for the aliases as well as the primary service name would the primary service name is inefficient, and achieves nothing that
be inefficient, and achieves nothing that it not already achieved is not already achieved by using the service name "http"
by using the service name "http" exclusively. exclusively.
o As indicated in this document, in Section 10.1, to enable legacy o As indicated in this document in Section 10.1, overloading has
names to be replaced with names consistent with the syntax this been used to create replacement names that are consistent with the
document prescribes. In this case, only the new name should be syntax this document prescribes for legacy names that do not
used in SRV records, both to avoid the same issues as with conform to this syntax already. For such cases, only the new name
historical cases of multiple names, as well as because the legacy should be used in SRV records, to avoid the same issues as with
historical cases of multiple names, and also because the legacy
names are incompatible with SRV record use. names are incompatible with SRV record use.
For future assignments, applications will not be permitted that For future assignments, applications will not be permitted that
merely request a new name exactly duplicating an existing service. merely request a new name exactly duplicating an existing service.
Having multiple names for the same service serves no purpose. Having multiple names for the same service serves no purpose.
Implementers are requested to inform IANA if they discover other Implementers are requested to inform IANA if they discover other
cases where a single service has multiple names, so that one name may cases where a single service has multiple names, so that one name may
be recorded as the primary name for service discovery purposes. be recorded as the primary name for service discovery purposes.
Service names are assigned on a "first come, first served" basis, as Service names are assigned on a "first come, first served" basis, as
skipping to change at page 9, line 31 skipping to change at page 9, line 45
'a' - 'z', digits '0' - '9', and hyphens ('-', ASCII 0x2D or 'a' - 'z', digits '0' - '9', and hyphens ('-', ASCII 0x2D or
decimal 45) decimal 45)
o MUST contain at least one letter ('A' - 'Z' or 'a' - 'z') o MUST contain at least one letter ('A' - 'Z' or 'a' - 'z')
o MUST NOT begin or end with a hyphen o MUST NOT begin or end with a hyphen
o hyphens MUST NOT be adjacent to other hyphens o hyphens MUST NOT be adjacent to other hyphens
The reason for requiring at least one letter is to avoid service The reason for requiring at least one letter is to avoid service
names like "23" (could be confused with a numeric port number) or names like "23" (could be confused with a numeric port) or "6000-
"6000-6063" (could be confused with a numeric port number range). 6063" (could be confused with a numeric port range). Although
Although service names may contain both upper-case and lower-case service names may contain both upper-case and lower-case letters,
letters, case is ignored for comparison purposes, so both "http" and case is ignored for comparison purposes, so both "http" and "HTTP"
"HTTP" denote the same service. denote the same service.
Service names are purely opaque identifiers, and no semantics are Service names are purely opaque identifiers, and no semantics are
implied by any superficial structure that a given service name may implied by any superficial structure that a given service name may
appear to have. For example, a company called "Example" may choose appear to have. For example, a company called "Example" may choose
to register service names "Example-Foo" and "Example-Bar" for its to register service names "Example-Foo" and "Example-Bar" for its
"Foo" and "Bar" products, but the "Example" company can't claim to "Foo" and "Bar" products, but the "Example" company cannot claim to
"own" all service names beginning with "Example-", they can't prevent "own" all service names beginning with "Example-"; they cannot
someone else registering "Example-Baz" for a different service, and prevent someone else from registering "Example-Baz" for a different
they can't prevent other developers from using the "Example-Foo" and service, and they cannot prevent other developers from using the
"Example-Bar" service types in order to interoperate with the "Foo" "Example-Foo" and "Example-Bar" service types in order to
and "Bar" products. Technically speaking, in service discovery interoperate with the "Foo" and "Bar" products. Technically
protocols, service names are merely a series of byte values on the speaking, in service discovery protocols, service names are merely a
wire; for the mnemonic convenience of human developers it can be series of byte values on the wire; for the mnemonic convenience of
convenient to interpret those byte values as human-readable ascii human developers it can be convenient to interpret those byte values
characters, but software should treat them as purely opaque as human-readable ASCII characters, but software should treat them as
identifiers and not attempt to parse them for any additional embedded purely opaque identifiers and not attempt to parse them for any
meaning. additional embedded meaning.
In approximately 98% of cases, the new "service name" is exactly the In approximately 98% of cases, the new "service name" is exactly the
same as the old historic "short name" from the IANA web forms same as the old historic "short name" from the IANA web forms
[SYSFORM] [USRFORM]. In approximately 2% of cases, the new "service [SYSFORM] [USRFORM]. In approximately 2% of cases, the new "service
name" is derived from the old historic "short name" as described name" is derived from the old historic "short name" as described
below in Section 10.1. below in Section 10.1.
The rules for valid service names, excepting the limit of 15 The rules for valid service names, excepting the limit of 15
characters maximum, are also expressed below (as a non-normative characters maximum, are also expressed below (as a non-normative
convenience) using ABNF [RFC5234]. convenience) using ABNF [RFC5234].
skipping to change at page 10, line 30 skipping to change at page 10, line 43
DIGIT = %x30-39 ; 0-9 [RFC5234] DIGIT = %x30-39 ; 0-9 [RFC5234]
5.2. Service Name Usage in DNS SRV Records 5.2. Service Name Usage in DNS SRV Records
The DNS SRV specification [RFC2782] states that the Service Label The DNS SRV specification [RFC2782] states that the Service Label
part of the owner name of a DNS SRV record includes a "Service" part of the owner name of a DNS SRV record includes a "Service"
element, described as "the symbolic name of the desired service", but element, described as "the symbolic name of the desired service", but
as discussed above, it is not clear precisely what this means. as discussed above, it is not clear precisely what this means.
This document clarifies that the Service Label MUST be a service name This document clarifies that the Service Label MUST be a service name
as defined herein. The service name SHOULD be registered with IANA as defined herein with an underscore prepended. The service name
and recorded in the Service Name and Transport Protocol Port Number SHOULD be registered with IANA and recorded in the Service Name and
Registry [PORTREG]. Transport Protocol Port Number Registry [PORTREG].
The details of using Service Names in SRV Service Labels are The details of using Service Names in SRV Service Labels are
specified in the DNS SRV specification [RFC2782]. This document does specified in the DNS SRV specification [RFC2782]. This document does
not change that specification. not change that specification.
6. Port Number Ranges 6. Port Number Ranges
TCP, UDP, UDP-Lite, SCTP and DCCP use 16-bit namespaces for their TCP, UDP, UDP-Lite, SCTP and DCCP use 16-bit namespaces for their
port number registries. The port registries for all these transport port number registries. The port registries for all these transport
protocols are subdivided into three ranges of numbers, and protocols are subdivided into three ranges of numbers, and
skipping to change at page 11, line 15 skipping to change at page 11, line 25
o the User Ports, also known as the Registered Ports, from 1024- o the User Ports, also known as the Registered Ports, from 1024-
49151 (assigned by IANA) 49151 (assigned by IANA)
o the Dynamic Ports, also known as the Private Ports, from 49152- o the Dynamic Ports, also known as the Private Ports, from 49152-
65535 (never assigned) 65535 (never assigned)
Of the assignable port ranges (System Ports and User Ports, i.e., Of the assignable port ranges (System Ports and User Ports, i.e.,
port numbers 0-49151), individual port numbers are in one of three port numbers 0-49151), individual port numbers are in one of three
states at any given time: states at any given time:
o Assigned: Assigned port numbers are currently allocated to the o Assigned: Assigned port numbers are currently assigned to the
service indicated in the registry. service indicated in the registry.
o Unassigned: Unassigned port numbers are currently available for o Unassigned: Unassigned port numbers are currently available for
assignment upon request, as per the procedures outlined in this assignment upon request, as per the procedures outlined in this
document. document.
o Reserved: Reserved port numbers are not available for regular o Reserved: Reserved port numbers are not available for regular
assignment; they are "assigned to IANA" for special purposes. assignment; they are "assigned to IANA" for special purposes.
Reserved port numbers include values at the edges of each range, Reserved port numbers include values at the edges of each range,
e.g., 0, 1023, 1024, etc., which may be used to extend these e.g., 0, 1023, 1024, etc., which may be used to extend these
ranges or the overall port number space in the future. ranges or the overall port number space in the future.
In order to keep the size of the registry manageable, IANA typically In order to keep the size of the registry manageable, IANA typically
only records the Assigned and Reserved service names and port numbers only records the Assigned and Reserved service names and port numbers
in the registry. Unassigned values are typically not explicitly in the registry. Unassigned values are typically not explicitly
listed. (There are an near-infinite number of Unassigned service listed. (There are a near-infinite number of Unassigned service
names and enumerating them all would not be practical.) names and enumerating them all would not be practical.)
As a data point, when this document was written, approximately 76% of As a data point, when this document was written, approximately 76% of
the TCP and UDP System Ports were assigned, and approximately 9% of the TCP and UDP System Ports were assigned, and approximately 9% of
the User Ports were assigned. (As noted, Dynamic Ports are never the User Ports were assigned. (As noted, Dynamic Ports are never
assigned.) assigned.)
6.1. Service names and Port Numbers for Experimentation 6.1. Service names and Port Numbers for Experimentation
Of the System Ports, two TCP and UDP port numbers (1021 and 1022), Of the System Ports, two TCP and UDP port numbers (1021 and 1022),
together with their respective service names ("exp1" and "exp2"), together with their respective service names ("exp1" and "exp2"),
have been assigned for experimentation with new applications and have been assigned for experimentation with new applications and
application-layer protocols that require a port number in the application-layer protocols that require a port number in the
assigned ports ranges [RFC4727]. assigned ports ranges [RFC4727].
Please refer to Sections 1 and 1.1 of "Assigning Experimental and Please refer to Sections 1 and 1.1 of "Assigning Experimental and
Testing Numbers Considered Useful" [RFC3692] for how these Testing Numbers Considered Useful" [RFC3692] for how these
experimental port numbers are to be used. experimental port numbers are to be used.
This document registers the same two service names and port numbers This document assigns the same two service names and port numbers for
for experimentation with new application-layer protocols over SCTP experimentation with new application-layer protocols over SCTP and
and DCCP in Section 10.2. DCCP in Section 10.2.
Unfortunately, it can be difficult to limit access to these ports. Unfortunately, it can be difficult to limit access to these ports.
Users SHOULD take measures to ensure that experimental ports are Users SHOULD take measures to ensure that experimental ports are
connecting to the intended process. For example, users of these connecting to the intended process. For example, users of these
experimental ports might include a 64-bit nonce, once on each segment experimental ports might include a 64-bit nonce, once on each segment
of a message-oriented channel (e.g., UDP), or once at the beginning of a message-oriented channel (e.g., UDP), or once at the beginning
of a byte-stream (e.g., TCP), which is used to confirm that the port of a byte-stream (e.g., TCP), which is used to confirm that the port
is being used as intended. Such confirmation of intended use is is being used as intended. Such confirmation of intended use is
especially important when these ports are associated with privileged especially important when these ports are associated with privileged
(e.g., system or administrator) processes. (e.g., system or administrator) processes.
7. Principles for Service Name and Transport Protocol Port Number 7. Principles for Service Name and Transport Protocol Port Number
Registry Management Registry Management
Management procedures for the service name and transport protocol Management procedures for the service name and transport protocol
port number registry include allocation of service names and port port number registry include assignment of service names and port
numbers upon request, as well as management of information about numbers upon request, as well as management of information about
existing allocations. The latter includes maintaining contact and existing assignments. The latter includes maintaining contact and
description information about assignments, revoking abandoned description information about assignments, revoking abandoned
assignments, and redefining assignments when needed. Of these assignments, and redefining assignments when needed. Of these
procedures, careful port number allocation is most critical, in order procedures, careful port number assignment is most critical, in order
to continue to conserve the remaining port numbers. to continue to conserve the remaining port numbers.
As noted earlier, only about 9% of the User Port space is currently As noted earlier, only about 9% of the User Port space is currently
assigned. The current rate of assignment is approximately 400 ports assigned. The current rate of assignment is approximately 400 ports
per year, and has remained steady for the past 8 years. At that per year, and has remained steady for the past 8 years. At that
rate, if similar conservation continues, this resource will sustain rate, if similar conservation continues, this resource will sustain
another 85 years of assignment - without the need to resort to another 85 years of assignment - without the need to resort to
reassignment of released values or revocation. The namespace reassignment of released values or revocation. The namespace
available for service names is much larger, which allows for simpler available for service names is much larger, which allows for simpler
management procedures. management procedures.
7.1. Past Principles 7.1. Past Principles
Before the publication of this document, the principles of service The principles for service name and port number management are based
name and port number management followed a few mostly-undocumented on the recommendations of the IANA "Expert Review" team. Until
guidelines. They are recorded here for historical purposes, and this recently, that team followed a set of informal guidelines developed
document updates them in Section 7.2. These principles were: based on the review experience from previous assignment requests.
These original guidelines, although informal, had never been publicly
documented. They are recorded here for historical purposes only; the
current guidelines are described in Section 7.2. These guidelines
previously were:
o TCP and UDP ports were simultaneously allocated when either was o TCP and UDP ports were simultaneously assigned when either was
requested requested
o Port numbers were the primary allocation; service names were o Port numbers were the primary assignment; service names were
informative only, and did not have a well-defined syntax informative only, and did not have a well-defined syntax
o Port numbers were conserved informally, and sometimes o Port numbers were conserved informally, and sometimes
inconsistently (e.g., some services were allocated ranges of many inconsistently (e.g., some services were assigned ranges of many
port numbers even where not strictly necessary) port numbers even where not strictly necessary)
o SCTP and DCCP service name and port number registries were managed o SCTP and DCCP service name and port number registries were managed
separately from the TCP/UDP registries separately from the TCP/UDP registries
o Service names could not be assigned in the old ports registry o Service names could not be assigned in the old ports registry
without assigning an associated port number at the same time without assigning an associated port number at the same time
This document clarifies and aligns these guidelines in order to more
conservatively manage the limited remaining port number space and to
enable and promote the use of service names for service
identification without associated port numbers, where possible.
7.2. Updated Principles 7.2. Updated Principles
This section summarizes the basic principles by which IANA handles This section summarizes the current principles by which IANA handles
the Service Name and Transport Protocol Port Number Registry, and the Service Name and Transport Protocol Port Number Registry and
attempts to conserve the port number space. This description is attempts to conserve the port number space. This description is
intended to inform applicants requesting service names and port intended to inform applicants requesting service names and port
numbers. IANA are not required to be bound by these principles when numbers. IANA has flexibility beyond these principles when handling
handling requests; other factors may come into play, and exceptions assignment requests; other factors may come into play, and exceptions
may occur where deemed in the best interest of the Internet. may be made to best serve the needs of the Internet.
IANA will begin assigning service names that do not request an IANA strives to assign service names that do not request an
associated port number allocation under a simple "First Come, First associated port number assignment under a simple "First Come, First
Served" policy [RFC5226]. IANA MAY, at its discretion, refer service Served" policy [RFC5226]. IANA MAY, at its discretion, refer service
name requests to "Expert Review" in cases of mass registrations or name requests to "Expert Review" in cases of mass assignment requests
other situations where IANA believes expert review is advisable. or other situations where IANA believes expert review is advisable.
The basic principle of service name and port number registry The basic principle of service name and port number registry
management is to conserve use of the port space where possible. management is to conserve use of the port space where possible.
Extensions to support larger port number spaces would require Extensions to support larger port number spaces would require
changing many core protocols of the current Internet in a way that changing many core protocols of the current Internet in a way that
would not be backward compatible and interfere with both current and would not be backward compatible and interfere with both current and
legacy applications. To help ensure this conservation the policy for legacy applications. To help ensure this conservation the policy for
any registration request for port number allocations uses the "Expert any assignment request for port number assignments uses the "Expert
Review" policy [RFC5226]. Review" policy [RFC5226].
Conservation of the port number space is required because this space Conservation of the port number space is required because this space
is a limited resource, so applications are expected to participate in is a limited resource, so applications are expected to participate in
the traffic demultiplexing process where feasible. The port numbers the traffic demultiplexing process where feasible. The port numbers
are expected to encode as little information as possible that will are expected to encode as little information as possible that will
still enable an application to perform further demultiplexing by still enable an application to perform further demultiplexing by
itself. In particular: itself. In particular, the principles form a goal that IANA strives
to achieve for new applications (with exceptions as deemed
appropriate, especially as for extensions to legacy services) as
follows:
o IANA will allocate only one assigned port number per service or o IANA strives to assign only one assigned port number per service
application or application
o IANA will allocate only one assigned port number for all versions o IANA strives to assign only one assigned port number for all
of a service (e.g., running the service with or without a security variants of a service (e.g., for updated versions of a service)
mechanism, or for updated variants of a service)
o IANA will allocate only one assigned port number for all different o IANA strives to encourage the deployment of secure protocols, and
types of device using or participating in the same service so strives to avoid separate assignments for non-secure variants
o IANA will allocate port numbers only for the transport protocol(s) o IANA strives to assign only one assigned port number for all
explicitly named in a registration request different types of device using or participating in the same
service
o IANA strives to assign port numbers only for the transport
protocol(s) explicitly named in an assignment request
o IANA may recover unused port numbers, via the new procedures of o IANA may recover unused port numbers, via the new procedures of
de-registration, revocation, and transfer de-assignment, revocation, and transfer
Where possible, a given service is expected to demultiplex messages Where possible, a given service is expected to demultiplex messages
if necessary. For example, applications and protocols are expected if necessary. For example, applications and protocols are expected
to include in-band version information, so that future versions of to include in-band version information, so that future versions of
the application or protocol can share the same allocated port. the application or protocol can share the same assigned port.
Applications and protocols are also expected to be able to Applications and protocols are also expected to be able to
efficiently use a single allocated port for multiple sessions, either efficiently use a single assigned port for multiple sessions, either
by demultiplexing multiple streams within one port, or using the by demultiplexing multiple streams within one port, or using the
allocated port to coordinate using dynamic ports for subsequent assigned port to coordinate using dynamic ports for subsequent
exchanges (e.g., in the spirit of FTP [RFC0959]). exchanges (e.g., in the spirit of FTP [RFC0959]).
Ports are used in various ways, notably: Ports are used in various ways, notably:
o as endpoint process identifiers o as endpoint process identifiers
o as application protocol identifiers o as application protocol identifiers
o for firewall filtering purposes o for firewall filtering purposes
Both the process identifier and the protocol identifier uses suggest Both the process identifier and the protocol identifier uses suggest
that anything a single process can demultiplex, or that can be that anything a single process can demultiplex, or that can be
encoded into a single protocol, should be. The firewall filtering encoded into a single protocol, should be. The firewall filtering
use suggests that some uses that could be multiplexed or encoded use suggests that some uses that could be multiplexed or encoded
could instead be separated to allow for easier firewall management. could instead be separated to allow for easier firewall management.
Note that this latter use is much less sound, because port numbers Note that this latter use is much less sound, because port numbers
have meaning only for the two endpoints involved in a connection, and have meaning only for the two endpoints involved in a connection, and
drawing conclusions about the service that generated a given flow drawing conclusions about the service that generated a given flow
based on observed port numbers is not always reliable. Further, based on observed port numbers is not always reliable. Further, the
previous separation of protocol variants based on security previous practice of separating protocol variants based on security
capabilities (e.g., HTTP on TCP port 80 vs. HTTPS on TCP port 443) is capabilities (e.g., HTTP on TCP port 80 vs. HTTPS on TCP port 443) is
not recommended for new protocols, because all new protocols should not recommended for new protocols, because all new protocols should
be security-capable and capable of negotiating the use of security be security-capable.
in-band.
IANA will begin assigning port numbers for only those transport IANA will begin assigning port numbers for only those transport
protocols explicitly included in a registration request. This ends protocols explicitly included in an assignment request. This ends
the long-standing practice of automatically assigning a port number the long-standing practice of automatically assigning a port number
to an application for both TCP and a UDP, even if the request is for to an application for both TCP and a UDP, even if the request is for
only one of these transport protocols. The new allocation procedure only one of these transport protocols. The new assignment procedure
conserves resources by allocating a port number to an application for conserves resources by assigning a port number to an application for
only those transport protocols (TCP, UDP, SCTP and/or DCCP) it only those transport protocols (TCP, UDP, SCTP and/or DCCP) it
actually uses. The port number will be marked as Reserved - instead actually uses. The port number will be marked as Reserved - instead
of Assigned - in the port number registries of the other transport of Assigned - in the port number registries of the other transport
protocols. When applications start supporting the use of some of protocols. When applications start supporting the use of some of
those additional transport protocols, the Registrant for the those additional transport protocols, the Assignee for the assignment
registration MUST request IANA to convert the reservation into a MUST request IANA convert these reserved ports into assignments. An
proper assignment. An application MUST NOT assume that it can use a application MUST NOT assume that it can use a port number assigned to
port number assigned to it for use with one transport protocol with it for use with one transport protocol with another transport
another transport protocol without asking IANA to convert the protocol without asking IANA to convert the reserved ports into an
reservation into an assignment. assignment.
When the available pool of unassigned numbers has run out in a ports When the available pool of unassigned numbers has run out in a ports
range, it will be necessary for IANA to consider the Reserved ports range, it will be necessary for IANA to consider the Reserved ports
for assignment. This is part of the motivation for not automatically for assignment. This is part of the motivation for not automatically
assigning ports for transport protocols other than the requested assigning ports for transport protocols other than the requested
one(s). This will allow more ports to be available for assignment one(s). This will allow more ports to be available for assignment
when that time comes. To help conserve ports, application developers when that time comes. To help conserve ports, application developers
should register only the transport protocols that their application should request assignment of only the transport protocols that their
currently uses. application currently uses.
Conservation of port numbers is improved by procedures that allow Conservation of port numbers is improved by procedures that allow
previously allocated port numbers to become Unassigned, either previously allocated port numbers to become Unassigned, either
through de-registration or through revocation, and by a procedure through de-assignment or through revocation, and by a procedure that
that lets application designers transfer an allocated but unused port lets application designers transfer an assigned but unused port
number to a new application. Section 8 describes these procedures, number to a new application. Section 8 describes these procedures,
which until now were undocumented. Port number conservation is also which until now were undocumented. Port number conservation is also
improved by recommending that applications that do not require an improved by recommending that applications that do not require an
allocated port should register only a service name without an assigned port should register only a service name without an
associated port number. associated port number.
8. IANA Procedures for Managing the Service Name and Transport Protocol 8. IANA Procedures for Managing the Service Name and Transport Protocol
Port Number Registry Port Number Registry
This section describes the process for handling requests associated This section describes the process for handling requests associated
with IANA's management of the Service Name and Transport Protocol with IANA's management of the Service Name and Transport Protocol
Port Number Registry. Such requests include initial registration, Port Number Registry. Such requests include initial assignment, de-
de-registration, re-use, changes to the service name, and updates to assignment, reuse, changes to the service name, and updates to the
the contact information or description associated with an assignment. contact information or description associated with an assignment.
Revocation is as additional process, initiated by IANA. Revocation is as additional process, initiated by IANA.
8.1. Service Name and Port Number Registration 8.1. Service Name and Port Number Assignment
Registration refers to the allocation of service names or port Assignment refers to the process of providing service names or port
numbers to applicants. All such registrations are made from service numbers to applicants. All such assignments are made from service
names or port numbers that are Unassigned or Reserved at the time of names or port numbers that are Unassigned or Reserved at the time of
the allocation. Unassigned names and numbers are allocated according the assignment. Unassigned names and numbers are allocated according
to the rules described in Section 8.1.1 below. Reserved numbers and to the rules described in Section 8.1.1 below. Except as described
names are assigned only by Standards Action or IESG Approval, and below, Reserved numbers and names are assigned only by a Standards
MUST accompanied by a statement explaining the reason a Reserved Action or an IESG Approval, and MUST accompanied by a statement
number or name is appropriate for this action. explaining the reason a Reserved number or name is appropriate for
this action.
When a registration for one or more transport protocols is approved, When an assignment for one or more transport protocols is approved,
the port number for any non-requested transport protocol(s) will be the port number for any non-requested transport protocol(s) will be
marked as Reserved. IANA SHOULD NOT assign that port number to any marked as Reserved. IANA SHOULD NOT assign that port number to any
other application or service until no other port numbers remain other application or service until no other port numbers remain
Unassigned in the requested range. The current Registrant for a port Unassigned in the requested range. The current Assignee for a port
number MAY register these Reserved port numbers for other transport number MAY request assignment of these Reserved port numbers for
protocols when needed. other transport protocols when needed.
A service name or port number registration request contains the A service name or port number assignment request contains the
following information. The service name is the unique identifier of following information. The service name is the unique identifier of
a given service: a given service:
Service Name (REQUIRED) Service Name (REQUIRED)
Transport Protocol(s) (REQUIRED) Transport Protocol(s) (REQUIRED)
Registrant (REQUIRED) Assignee (REQUIRED)
Contact (REQUIRED) Contact (REQUIRED)
Description (REQUIRED) Description (REQUIRED)
Reference (REQUIRED) Reference (REQUIRED)
Port Number (OPTIONAL) Port Number (OPTIONAL)
Service Code (REQUIRED for DCCP only) Service Code (REQUIRED for DCCP only)
Known Unauthorized Uses (OPTIONAL) Known Unauthorized Uses (OPTIONAL)
Assignment Notes (OPTIONAL) Assignment Notes (OPTIONAL)
o Service Name: A desired unique service name for the service o Service Name: A desired unique service name for the service
associated with the registration request MUST be provided, for use associated with the assignment request MUST be provided, for use
in various service selection and discovery mechanisms (including, in various service selection and discovery mechanisms (including,
but not limited to, DNS SRV records [RFC2782]). The name MUST be but not limited to, DNS SRV records [RFC2782]). The name MUST be
compliant with the syntax defined in Section 5.1. In order to be compliant with the syntax defined in Section 5.1. In order to be
unique, they MUST NOT be identical to any currently assigned unique, they MUST NOT be identical to any currently assigned
service name in the IANA registry [PORTREG]. Service names are service name in the IANA registry [PORTREG]. Service names are
case-insensitive; they may be provided and entered into the case-insensitive; they may be provided and entered into the
registry with mixed case for clarity, but for the comparison registry with mixed case for clarity, but for the comparison
purposes the case is ignored. purposes the case is ignored.
o Transport Protocol(s): The transport protocol(s) for which a o Transport Protocol(s): The transport protocol(s) for which an
allocation is requested MUST be provided. This field is currently assignment is requested MUST be provided. This field is currently
limited to one or more of TCP, UDP, SCTP, and DCCP. Requests limited to one or more of TCP, UDP, SCTP, and DCCP. Requests
without any port allocation and only a service name are still without any port assignment and only a service name are still
required to indicate which protocol the service uses. required to indicate which protocol the service uses.
o Registrant: Name and email address of the Registrant. This is o Assignee: Name and email address of the party to whom the
REQUIRED. The Registrant is the Organization or Company assignment is made. This is REQUIRED. The Assignee is the
responsible for the initial registration. For registrations done Organization or Company responsible for the initial assignment.
through IETF-published RFCs, the Registrant will be the IESG. For assignments done through IETF-published RFCs, the Assignee
will be the IETF, with the IESG <iesg@ietf.org> as the point of
contact.
o Contact: Name and email address of the Contact person for the o Contact: Name and email address of the Contact person for the
registration. This is REQUIRED. The Contact person is the assignment. This is REQUIRED. The Contact person is the
responsible person for the Internet community to send questions responsible person for the Internet community to send questions
to. This person would also be authorized to submit changes on to. This person is also authorized to submit changes on behalf of
behalf of the Registrant; in cases of conflict between the the Assignee; in cases of conflict between the Assignee and the
Registrant and the Contact, the Registrant decisions take Contact, the Assignee decisions take precedence. Additional
precedence. Additional address information MAY be provided. For address information MAY be provided. For assignments done through
registrations done through IETF-published RFCs, the Contact will IETF-published RFCs, the Contact will be the IESG.
be the IESG.
o Description: A short description of the service associated with o Description: A short description of the service associated with
the registration request is REQUIRED. It should avoid all but the the assignment request is REQUIRED. It should avoid all but the
most well-known acronyms. most well-known acronyms.
o Reference: A description of (or a reference to a document o Reference: A description of (or a reference to a document
describing) the protocol or application using this port. The describing) the protocol or application using this port. The
description must state whether the protocol uses broadcast, description must state whether the protocol uses broadcast,
multicast, or anycast communication. multicast, or anycast communication.
For registrations requesting only a Service Name, or a Service For assignments requesting only a Service Name, or a Service Name
Name and User Port, a statement that the protocol is proprietary and User Port, a statement that the protocol is proprietary and
and not publicly documented is also acceptable provided that the not publicly documented is also acceptable provided that the
required information regarding use of broadcast, multicast, or required information regarding use of broadcast, multicast, or
anycast is given. anycast is given.
For registration requests for a User Port, the registration For assignment requests for a User Port, the assignment request
request MUST explain why a port number in the Dynamic Ports range MUST explain why a port number in the Dynamic Ports range is
is unsuitable for the given application. unsuitable for the given application.
For registration requests for a System Port, the registration For assignment requests for a System Port, the assignment request
request MUST explain why a port number in the User Ports or MUST explain why a port number in the User Ports or Dynamic Ports
Dynamic Ports ranges is unsuitable, and a reference to a stable ranges is unsuitable, and a reference to a stable protocol
protocol specification document MUST be provided. For requests specification document MUST be provided. For requests from IETF
from IETF Working Groups, IANA MAY accept "early registration" Working Groups, IANA MAY accept early assignment [RFC4020]
[RFC4020] requests referencing a sufficiently stable Internet requests (known as "early allocation" therein) referencing a
Draft instead of a published Standards-Track RFC. sufficiently stable Internet Draft instead of a published
Standards-Track RFC.
o Port Number: If assignment of a port number is desired, either the o Port Number: If assignment of a port number is desired, either the
currently Unassigned or Reserved port number the requester port number the requester suggests for assignment or indication of
suggests for allocation, or indication of which port range, user port range (user or system) MUST be provided. If only a service
or system, that the requester requires, MUST be provided. If only name is to be assigned, this field is left empty. If a specific
a service name is to be assigned, this field is left empty. If a port number is requested, IANA is encouraged to assign the
specific port number is requested, IANA is encouraged to allocate requested number. If a range is specified, IANA will choose a
the requested number. If a range is specified, IANA will choose a
suitable number from the User or System Ports ranges. Note that suitable number from the User or System Ports ranges. Note that
the applicant MUST NOT use the requested port prior to the the applicant MUST NOT use the requested port prior to the
completion of the registration. completion of the assignment.
o Service Code: If the registration request includes DCCP as a o Service Code: If the assignment request includes DCCP as a
transport protocol then the request MUST include a desired unique transport protocol then the request MUST include a desired unique
DCCP service code [RFC5595], and MUST NOT include a requested DCCP DCCP service code [RFC5595], and MUST NOT include a requested DCCP
service code otherwise. Section 19.8 of the DCCP specification service code otherwise. Section 19.8 of the DCCP specification
[RFC4340] defines requirements and rules for allocation, updated [RFC4340] defines requirements and rules for assignment, updated
by this document. by this document.
o Known Unauthorized Uses: A list of uses by applications or o Known Unauthorized Uses: A list of uses by applications or
organizations who are not the Registrant. This list may be organizations who are not the Assignee. This list may be
augmented by IANA after assignment when unauthorized uses are augmented by IANA after assignment when unauthorized uses are
reported. reported.
o Assignment Notes: Indications of owner/name change, or any other o Assignment Notes: Indications of owner/name change, or any other
assignment process issue. This list may be updated by IANA after assignment process issue. This list may be updated by IANA after
assignment to help track changes to an assignment, e.g., de- assignment to help track changes to an assignment, e.g., de-
registration, owner/name changes, etc. assignment, owner/name changes, etc.
If the registration request is for the addition of a new transport If the assignment request is for the addition of a new transport
protocol to an already assigned service name, IANA needs to confirm protocol to an already-assigned service name and the requester is not
with the Registrant for the existing assignment whether this addition the Assignee or Contact for the already-assigned service name, IANA
is appropriate. needs to confirm with the Assignee for the existing assignment
whether this addition is appropriate.
If the registration request is for a service name overloading a port If the assignment request is for a new service name sharing the same
number (see Section 5), IANA needs to confirm with the Registrant for port as an already-assigned service name (see port number overloading
the existing service name whether the registration of the overloading in Section 5), IANA needs to confirm with the Assignee for the
is appropriate. existing service name and other appropriate experts whether the
overloading is appropriate.
When IANA receives a registration request - containing the above When IANA receives an assignment request - containing the above
information - that is requesting a port number, IANA SHALL initiate information - that is requesting a port number, IANA SHALL initiate
an "Expert Review" [RFC5226] in order to determine whether an an "Expert Review" [RFC5226] in order to determine whether an
assignment should be made. For requests that are not requesting a assignment should be made. For requests that are not seeking a port
port number, IANA SHOULD assign the service name under a simple number, IANA SHOULD assign the service name under a simple "First
"First Come First Served" policy [RFC5226]. Come First Served" policy [RFC5226].
8.1.1. Variances for Specific Port Number Ranges 8.1.1. Variances for Specific Port Number Ranges
Section 6 describes the different port number ranges. It is Section 6 describes the different port number ranges. It is
important to note that IANA applies slightly different procedures important to note that IANA applies slightly different procedures
when managing the different port ranges of the service name and port when managing the different port ranges of the service name and port
number registry: number registry:
o Ports in the Dynamic Ports range (49152-65535) have been o Ports in the Dynamic Ports range (49152-65535) have been
specifically set aside for local and dynamic use and cannot be specifically set aside for local and dynamic use and cannot be
assigned through IANA. Application software may simply use them assigned through IANA. Application software may simply use any
for communication without any sort of registration. On the other dynamic port that is available on the local host, without any sort
hand, application software MUST NOT assume that a specific port of assignment. On the other hand, application software MUST NOT
number in the Dynamic Ports range will always be available for assume that a specific port number in the Dynamic Ports range will
communication at all times, and a port number in that range hence always be available for communication at all times, and a port
MUST NOT be used as a service identifier. number in that range hence MUST NOT be used as a service
identifier.
o Ports in the User Ports range (1024-49151) are available for o Ports in the User Ports range (1024-49151) are available for
registration through IANA, and MAY be used as service identifiers assignment through IANA, and MAY be used as service identifiers
upon successful registration. Because registering a port number upon successful assignment. Because assigning a port number for a
for a specific application consumes a fraction of the shared specific application consumes a fraction of the shared resource
resource that is the port number registry, IANA will require the that is the port number registry, IANA will require the requester
requester to document the intended use of the port number. This to document the intended use of the port number. This
documentation will be input to the "Expert Review" allocation documentation will be input to the "Expert Review" procedure
procedure [RFC5226], by which IANA will have a technical expert [RFC5226], by which IANA will have a technical expert review the
review the request to determine whether to grant the registration. request to determine whether to grant the assignment. The
The submitted documentation MUST explain why using a port number submitted documentation MUST explain why using a port number in
in the Dynamic Ports range is unsuitable for the given the Dynamic Ports range is unsuitable for the given application.
application. Ports in the User Ports range may also be assigned Ports in the User Ports range may also be assigned under the "IETF
under the "IETF Review" or "IESG Approval" allocation procedures Review" or "IESG Approval" procedures [RFC5226], which is how most
[RFC5226], which is how most assignments for IETF protocols are assignments for IETF protocols are handled.
handled.
o Ports in the System Ports range (0-1023) are also available for o Ports in the System Ports range (0-1023) are also available for
registration through IANA. Because the System Ports range is both assignment through IANA. Because the System Ports range is both
the smallest and the most densely allocated, the requirements for the smallest and the most densely allocated, the requirements for
new allocations are more strict than those for the User Ports new assignments are more strict than those for the User Ports
range, and will only be granted under the "IETF Review" or "IESG range, and will only be granted under the "IETF Review" or "IESG
Approval" allocation procedures [RFC5226]. A request for a System Approval" procedures [RFC5226]. A request for a System Port
Port number MUST document *both* why using a port number from the number MUST document *both* why using a port number from the
User Ports is unsuitable *and* why using a port number from the Dynamic Ports range is unsuitable *and* why using a port number
Dynamic Ports ranges is unsuitable for that application. from the User Ports range is unsuitable for that application.
8.2. Service Name and Port Number De-Registration 8.2. Service Name and Port Number De-Assignment
The Registrant of a granted port number assignment can return the The Assignee of a granted port number assignment can return the port
port number to IANA at any time if they no longer have a need for it. number to IANA at any time if they no longer have a need for it. The
The port number will be de-registered and will be marked as Reserved. port number will be de-assigned and will be marked as Reserved. IANA
IANA should not re-assign port numbers that have been de-registered should not re-assign port numbers that have been de-assigned until
until all unassigned port numbers in the specific range have been all unassigned port numbers in the specific range have been assigned.
assigned.
Before proceeding with a port number de-registration, IANA needs to Before proceeding with a port number de-assignment, IANA needs to
reasonably establish that the value is actually no longer in use. reasonably establish that the value is actually no longer in use.
Because there is much less danger of exhausting the service name Because there is much less danger of exhausting the service name
space compared to the port number space, it is RECOMMENDED that a space compared to the port number space, it is RECOMMENDED that a
given service name remain assigned even after all associated port given service name remain assigned even after all associated port
number assignments have become de-registered. Under this policy, it number assignments have become de-assigned. Under this policy, it
will appear in the registry as if it had been created through a will appear in the registry as if it had been created through a
service name registration request that did not include any port service name assignment request that did not include any port
numbers. numbers.
On rare occasions, it may still be useful to de-register a service On rare occasions, it may still be useful to de-assign a service
name. In such cases, IANA will mark the service name as Reserved. name. In such cases, IANA will mark the service name as Reserved.
IANA will involve their IESG-appointed expert in such cases. IANA will involve their IESG-appointed expert in such cases.
IANA will include a comment in the registry when de-registration IANA will include a comment in the registry when de-assignment
happens to indicate its historic usage. happens to indicate its historic usage.
8.3. Service Name and Port Number Re-Use 8.3. Service Name and Port Number Reuse
If the Registrant of a granted port number assignment no longer have If the Assignee of a granted port number assignment no longer has a
a need for the assigned number, but would like to re-use it for a need for the assigned number, but would like to reuse it for a
different application, they can submit a request to IANA to do so. different application, they can submit a request to IANA to do so.
Logically, port number re-use is to be thought of as a de- Logically, port number reuse is to be thought of as a de-assignment
registration (Section 8.2) followed by an immediate re-registration (Section 8.2) followed by an immediate (re-)assignment (Section 8.1)
(Section 8.1) of the same port number for a new application. of the same port number for a new application. Consequently, the
Consequently, the information that needs to be provided about the information that needs to be provided about the proposed new use of
proposed new use of the port number is identical to what would need the port number is identical to what would need to be provided for a
to be provided for a new port number allocation for the specific new port number assignment for the specific ports range.
ports range.
Because there is much less danger of exhausting the service name Because there is much less danger of exhausting the service name
space compared to the port number space, it is RECOMMENDED that the space compared to the port number space, it is RECOMMENDED that the
original service name associated with the prior use of the port original service name associated with the prior use of the port
number remains assigned, and a new service be created and associated number remains assigned, and a new service name be created and
with the port number. This is again consistent with viewing a re-use associated with the port number. This is again consistent with
request as a de-registration followed by an immediate re- viewing a reuse request as a de-assignment followed by an immediate
registration. Re-using an assigned service name for a different (re-)assignment. Re-using an assigned service name for a different
application is NOT RECOMMENDED. application is NOT RECOMMENDED.
IANA needs to carefully review such requests before approving them. IANA needs to carefully review such requests before approving them.
In some instances, the Expert Reviewer will determine that the In some instances, the Expert Reviewer will determine that the
application that the port number was assigned to has found usage application the port number was assigned to has found usage beyond
beyond the original requester, or that there is a concern that it may the original Assignee, or that there is a concern that it may have
have such users. This determination MUST be made quickly. A such users. This determination MUST be made quickly. A community
community call concerning revocation of a port number (see below) MAY call concerning revocation of a port number (see below) MAY be
be considered, if a broader use of the port number is suspected. considered, if a broader use of the port number is suspected.
8.4. Service Name and Port Number Revocation 8.4. Service Name and Port Number Revocation
A port number revocation can be thought of as an IANA-initiated de- A port number revocation can be thought of as an IANA-initiated de-
registration (Section 8.2), and has exactly the same effect on the assignment (Section 8.2), and has exactly the same effect on the
registry. registry.
Sometimes, it will be clear that a specific port number is no longer Sometimes, it will be clear that a specific port number is no longer
in use and that IANA can revoke it and mark it as Reserved. At other in use and that IANA can revoke it and mark it as Reserved. At other
times, it may be unclear whether a given assigned port number is times, it may be unclear whether a given assigned port number is
still in use somewhere in the Internet. In those cases, IANA must still in use somewhere in the Internet. In those cases, IANA must
carefully consider the consequences of revoking the port number, and carefully consider the consequences of revoking the port number, and
SHOULD only do so if there is an overwhelming need. SHOULD only do so if there is an overwhelming need.
With the help of their IESG-appointed Expert Reviewer, IANA SHALL With the help of their IESG-appointed Expert Reviewer, IANA SHALL
formulate a request to the IESG to issue a four-week community call formulate a request to the IESG to issue a four-week community call
concerning the pending port number revocation. The IESG and IANA, concerning the pending port number revocation. The IESG and IANA,
with the Expert Reviewer's support, SHALL determine promptly after with the Expert Reviewer's support, SHALL determine promptly after
the end of the community call whether revocation should proceed and the end of the community call whether revocation should proceed and
then communicate their decision to the community. This procedure then communicate their decision to the community. This procedure
typically involves similar steps to de-registration except that it is typically involves similar steps to de-assignment except that it is
initiated by IANA. initiated by IANA.
Because there is much less danger of exhausting the service name Because there is much less danger of exhausting the service name
space compared to the port number space, revoking service names is space compared to the port number space, revoking service names is
NOT RECOMMENDED. NOT RECOMMENDED.
8.5. Service Name and Port Number Transfers 8.5. Service Name and Port Number Transfers
The value of service names and port numbers is defined by their The value of service names and port numbers is defined by their
careful management as a shared Internet resource, whereas enabling careful management as a shared Internet resource, whereas enabling
transfer allows the potential for associated monetary exchanges. As transfer allows the potential for associated monetary exchanges. As
a result, the IETF does not permit service name or port number a result, the IETF does not permit service name or port number
assignments to be transferred between parties, even when they are assignments to be transferred between parties, even when they are
mutually consenting. mutually consenting.
The appropriate alternate procedure is a coordinated de-registration The appropriate alternate procedure is a coordinated de-assignment
and registration: The new party requests the service name or port and assignment: The new party requests the service name or port
number via a registration and the previous party releases its number via an assignment and the previous party releases its
assignment via the de-registration procedure outlined above. assignment via the de-assignment procedure outlined above.
With the help of their IESG-appointed Expert Reviewer, IANA SHALL With the help of their IESG-appointed Expert Reviewer, IANA SHALL
carefully determine if there is a valid technical, operational or carefully determine if there is a valid technical, operational or
managerial reason to grant the requested new assignment. managerial reason to grant the requested new assignment.
8.6. Maintenance Issues 8.6. Maintenance Issues
In addition to the formal procedures described above, updates to the In addition to the formal procedures described above, updates to the
Description and Contact information are coordinated by IANA in an Description and Contact information are coordinated by IANA in an
informal manner, and may be initiated by either the registrant or by informal manner, and may be initiated by either the Assignee or by
IANA, e.g., by the latter requesting an update to current contact IANA, e.g., by the latter requesting an update to current Contact
information. (Note that Registrant cannot be changed; see information. (Note that the Assignee cannot be changed as a separate
Section 8.5 above.) procedure; see instead Section 8.5 above.)
8.7. Disagreements 8.7. Disagreements
In the case of disagreements around any request there is the In the case of disagreements around any request there is the
possibility of appeal following the normal appelas process for IANA possibility of appeal following the normal appeals process for IANA
registrations as defined by Section 7 of "Guidelines for Writing an assignments as defined by Section 7 of "Guidelines for Writing an
IANA Considerations Section in RFCs" [RFC5226]. IANA Considerations Section in RFCs" [RFC5226].
9. Security Considerations 9. Security Considerations
The IANA guidelines described in this document do not change the The IANA guidelines described in this document do not change the
security properties of UDP, TCP, SCTP, or DCCP. security properties of UDP, TCP, SCTP, or DCCP.
Assignment of a service name or port number does not in any way imply Assignment of a service name or port number does not in any way imply
an endorsement of an application or product, and the fact that an endorsement of an application or product, and the fact that
network traffic is flowing to or from an assigned port number does network traffic is flowing to or from an assigned port number does
skipping to change at page 23, line 32 skipping to change at page 23, line 30
(see Section 5). (see Section 5).
10.1. Service Name Consistency 10.1. Service Name Consistency
Section 8.1 defines which character strings are well-formed service Section 8.1 defines which character strings are well-formed service
names, which until now had not been clearly defined. The definition names, which until now had not been clearly defined. The definition
in Section 8.1 was chosen to allow maximum compatibility of service in Section 8.1 was chosen to allow maximum compatibility of service
names with current and future service discovery mechanisms. names with current and future service discovery mechanisms.
As of August 5, 2009 approximately 98% of the so-called "Short Names" As of August 5, 2009 approximately 98% of the so-called "Short Names"
from existing port number registrations [PORTREG] meet the rules for from existing port number assignments [PORTREG] meet the rules for
legal service names stated in Section 8.1, and hence for these legal service names stated in Section 8.1, and hence for these
services their service name will be exactly the same as their "Short services their service name will be exactly the same as their "Short
Name". Name".
The remaining approximately 2% of the exiting "Short Names" are not The remaining approximately 2% of the exiting "Short Names" are not
suitable to be used directly as well-formed service names because suitable to be used directly as well-formed service names because
they contain illegal characters such as asterisks, dots, pluses, they contain illegal characters such as asterisks, dots, pluses,
slashes, or underscores. All existing "Short Names" conform to the slashes, or underscores. All existing "Short Names" conform to the
length requirement of 15 characters or fewer. For these unsuitable length requirement of 15 characters or fewer. For these unsuitable
"Short Names", listed in the table below, the service name will be "Short Names", listed in the table below, the service name will be
skipping to change at page 25, line 48 skipping to change at page 24, line 50
+----------------+-----------------+-----------------+ +----------------+-----------------+-----------------+
Following the example set by the "application/whoispp-query" MIME Following the example set by the "application/whoispp-query" MIME
Content-Type [RFC2957], the service name for "whois++" will be Content-Type [RFC2957], the service name for "whois++" will be
"whoispp". "whoispp".
10.2. Port Numbers for SCTP and DCCP Experimentation 10.2. Port Numbers for SCTP and DCCP Experimentation
Two System UDP and TCP ports, 1021 and 1022, have been reserved for Two System UDP and TCP ports, 1021 and 1022, have been reserved for
experimental use [RFC4727]. This document assigns the same port experimental use [RFC4727]. This document assigns the same port
numbers for SCTP and DCCP, updates the TCP and UDP registrations, and numbers for SCTP and DCCP, updates the TCP and UDP assignments, and
also instructs IANA to automatically assign these two port numbers also instructs IANA to automatically assign these two port numbers
for any future transport protocol with a similar 16-bit port number for any future transport protocol with a similar 16-bit port number
namespace. namespace.
Note that these port numbers are meant for temporary experimentation Note that these port numbers are meant for temporary experimentation
and development in controlled environments. Before using these port and development in controlled environments. Before using these port
numbers, carefully consider the advice in Section 6.1 in this numbers, carefully consider the advice in Section 6.1 in this
document, as well as in Sections 1 and 1.1 of "Assigning Experimental document, as well as in Sections 1 and 1.1 of "Assigning Experimental
and Testing Numbers Considered Useful" [RFC3692]. Most importantly, and Testing Numbers Considered Useful" [RFC3692]. Most importantly,
application developers must request a permanent port number application developers must request a permanent port number
assignment from IANA as described in Section 8.1 before any kind of assignment from IANA as described in Section 8.1 before any kind of
non-experimental deployment. non-experimental deployment.
+--------------------+----------------------------+ +--------------------+----------------------------+
| Registrant | IETF <iesg@ietf.org> |
| Contact | IESG <iesg@ietf.org> |
| Service Name | exp1 | | Service Name | exp1 |
| Port Number | 1021 |
| Transport Protocol | DCCP, SCTP, TCP, UDP | | Transport Protocol | DCCP, SCTP, TCP, UDP |
| Assignee | IETF <iesg@ietf.org> |
| Contact | IESG <iesg@ietf.org> |
| Description | RFC3692-style Experiment 1 | | Description | RFC3692-style Experiment 1 |
| Reference | [RFCyyyy],RFC 4727] | | Reference | [RFC4727] [RFCyyyy] |
| Port Number | 1021 |
+--------------------+----------------------------+ +--------------------+----------------------------+
+--------------------+----------------------------+ +--------------------+----------------------------+
| Registrant | IETF <iesg@ietf.org> |
| Contact | IESG <iesg@ietf.org> |
| Service Name | exp2 | | Service Name | exp2 |
| Port Number | 1022 |
| Transport Protocol | DCCP, SCTP, TCP, UDP | | Transport Protocol | DCCP, SCTP, TCP, UDP |
| Assignee | IETF <iesg@ietf.org> |
| Contact | IESG <iesg@ietf.org> |
| Description | RFC3692-style Experiment 2 | | Description | RFC3692-style Experiment 2 |
| Reference | [RFCyyyy], [RFC4727] | | Reference | [RFC4727] [RFCyyyy] |
| Port Number | 1022 |
+--------------------+----------------------------+ +--------------------+----------------------------+
[RFC Editor Note: Please change "yyyy" to the RFC number allocated to [RFC Editor Note: Please change "yyyy" to the RFC number allocated to
this document before publication.] this document before publication.]
10.3. Updates to DCCP Registries 10.3. Updates to DCCP Registries
This document updates the IANA allocation procedures for the DCCP This document updates the IANA assignment procedures for the DCCP
Port Number and DCCP Service Codes Registries [RFC4340]. Port Number and DCCP Service Codes Registries [RFC4340].
10.3.1. DCCP Service Code Registry 10.3.1. DCCP Service Code Registry
Service Codes are allocated first-come-first-served according to Service Codes are assigned first-come-first-served according to
Section 19.8 of the DCCP specification [RFC4340]. This document Section 19.8 of the DCCP specification [RFC4340]. This document
updates that section by extending the guidelines given there in the updates that section by extending the guidelines given there in the
following ways: following ways:
o IANA MAY assign new Service Codes without seeking Expert Review o IANA MAY assign new Service Codes without seeking Expert Review
using their discretion, but SHOULD seek expert review if a request using their discretion, but SHOULD seek expert review if a request
seeks more than five Service Codes. asks for more than five Service Codes.
o IANA should feel free to contact the DCCP Expert Reviewer with o IANA should feel free to contact the DCCP Expert Reviewer with
questions on any registry, regardless of the registry policy, for questions on any registry, regardless of the registry policy, for
clarification or if there is a problem with a request [RFC4340]. clarification or if there is a problem with a request [RFC4340].
10.3.2. DCCP Port Numbers Registry 10.3.2. DCCP Port Numbers Registry
The DCCP ports registry is defined by Section 19.9 of the DCCP The DCCP ports registry is defined by Section 19.9 of the DCCP
specification [RFC4340]. Allocations in this registry require prior specification [RFC4340]. Assignments in this registry require prior
allocation of a Service Code. Not all Service Codes require IANA- assignment of a Service Code. Not all Service Codes require IANA-
assigned ports. This document updates that section by extending the assigned ports. This document updates that section by extending the
guidelines given there in the following way: guidelines given there in the following way:
o IANA should normally assign a value in the range 1024-49151 to a o IANA should normally assign a value in the range 1024-49151 to a
DCCP server port. IANA allocation requests to allocate port DCCP server port. IANA requests to assign port numbers in the
numbers in the System Ports range (0 through 1023), require an System Ports range (0 through 1023), require an "IETF Review"
"IETF Review" [RFC5226] prior to allocation by IANA [RFC4340]. [RFC5226] prior to assignment by IANA [RFC4340].
o IANA MUST NOT allocate more than one DCCP server port to a single o IANA MUST NOT assign more than one DCCP server port to a single
service code value. service code value.
o The allocation of multiple service codes to the same DCCP port is o The assignment of multiple service codes to the same DCCP port is
allowed, but subject to expert review. allowed, but subject to expert review.
o The set of Service Code values associated with a DCCP server port o The set of Service Code values associated with a DCCP server port
should be recorded in the service name and port number registry. should be recorded in the service name and port number registry.
o A request for additional Service Codes to be associated with an o A request for additional Service Codes to be associated with an
already allocated Port Number requires Expert Review. These already-allocated Port Number requires Expert Review. These
requests will normally be accepted when they originate from the requests will normally be accepted when they originate from the
contact associated with the port registration. In other cases, contact associated with the port assignment. In other cases,
these applications will be expected to use an unallocated port, these applications will be expected to use an unallocated port,
when this is available. when this is available.
The DCCP specification [RFC4340] notes that a short port name MUST be The DCCP specification [RFC4340] notes that a short port name MUST be
associated with each DCCP server port that has been assigned. This associated with each DCCP server port that has been assigned. This
document clarifies that this short port name is the Service Name as document clarifies that this short port name is the Service Name as
defined here, and this name MUST be unique. defined here, and this name MUST be unique.
11. Contributors 11. Contributors
Alfred Hoenes (ah@tr-sys.de) and Allison Mankin (mankin@psg.com) have Alfred Hoenes (ah@tr-sys.de) and Allison Mankin (mankin@psg.com) have
contributed text and ideas to this document. contributed text and ideas to this document.
12. Acknowledgments 12. Acknowledgments
The text in Section 10.3 is based on a suggestion originally proposed The text in Section 10.3 is based on a suggestion originally proposed
as a part of the DCCP Service Codes document[RFC5595] by Gorry as a part of the DCCP Service Codes document [RFC5595] by Gorry
Fairhurst. Fairhurst.
Lars Eggert is partly funded by the Trilogy Project [TRILOGY], a Lars Eggert is partly funded by the Trilogy Project [TRILOGY], a
research project supported by the European Commission under its research project supported by the European Commission under its
Seventh Framework Program. Seventh Framework Program.
13. References 13. References
13.1. Normative References 13.1. Normative References
skipping to change at page 29, line 12 skipping to change at page 28, line 14
IANA Considerations Section in RFCs", BCP 26, RFC 5226, IANA Considerations Section in RFCs", BCP 26, RFC 5226,
May 2008. May 2008.
[RFC5234] Crocker, D. and P. Overell, "Augmented BNF for Syntax [RFC5234] Crocker, D. and P. Overell, "Augmented BNF for Syntax
Specifications: ABNF", STD 68, RFC 5234, January 2008. Specifications: ABNF", STD 68, RFC 5234, January 2008.
13.2. Informative References 13.2. Informative References
[I-D.cheshire-dnsext-dns-sd] [I-D.cheshire-dnsext-dns-sd]
Cheshire, S. and M. Krochmal, "DNS-Based Service Cheshire, S. and M. Krochmal, "DNS-Based Service
Discovery", draft-cheshire-dnsext-dns-sd-06 (work in Discovery", draft-cheshire-dnsext-dns-sd-07 (work in
progress), March 2010. progress), October 2010.
[I-D.cheshire-nat-pmp] [I-D.cheshire-nat-pmp]
Cheshire, S., "NAT Port Mapping Protocol (NAT-PMP)", Cheshire, S., "NAT Port Mapping Protocol (NAT-PMP)",
draft-cheshire-nat-pmp-03 (work in progress), April 2008. draft-cheshire-nat-pmp-03 (work in progress), April 2008.
[IGD] UPnP Forum, "Internet Gateway Device (IGD) V 1.0", [IGD] UPnP Forum, "Internet Gateway Device (IGD) V 1.0",
November 2001. November 2001.
[PORTREG] Internet Assigned Numbers Authority (IANA), "Service Name [PORTREG] Internet Assigned Numbers Authority (IANA), "Service Name
and Transport Protocol Port Number Registry", and Transport Protocol Port Number Registry",
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[RFC5766] Mahy, R., Matthews, P., and J. Rosenberg, "Traversal Using [RFC5766] Mahy, R., Matthews, P., and J. Rosenberg, "Traversal Using
Relays around NAT (TURN): Relay Extensions to Session Relays around NAT (TURN): Relay Extensions to Session
Traversal Utilities for NAT (STUN)", RFC 5766, April 2010. Traversal Utilities for NAT (STUN)", RFC 5766, April 2010.
[SRVREG] "DNS SRV Service Types Registry", [SRVREG] "DNS SRV Service Types Registry",
http://www.dns-sd.org/ServiceTypes.html. http://www.dns-sd.org/ServiceTypes.html.
[SYSFORM] Internet Assigned Numbers Authority (IANA), "Application [SYSFORM] Internet Assigned Numbers Authority (IANA), "Application
for System (Well Known) Port Number", for System (Well Known) Port Number",
http://www.iana.org/cgi-bin/sys-port-number.pl. http://www.iana.org/.
[TRILOGY] "Trilogy Project", http://www.trilogy-project.org/. [TRILOGY] "Trilogy Project", http://www.trilogy-project.org/.
[USRFORM] Internet Assigned Numbers Authority (IANA), "Application [USRFORM] Internet Assigned Numbers Authority (IANA), "Application
for User (Registered) Port Number", for User (Registered) Port Number", http://www.iana.org/.
http://www.iana.org/cgi-bin/usr-port-number.pl.
Authors' Addresses Authors' Addresses
Michelle Cotton Michelle Cotton
Internet Corporation for Assigned Names and Numbers Internet Corporation for Assigned Names and Numbers
4676 Admiralty Way, Suite 330 4676 Admiralty Way, Suite 330
Marina del Rey, CA 90292 Marina del Rey, CA 90292
USA USA
Phone: +1 310 823 9358 Phone: +1 310 823 9358
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