One document matched: draft-ietf-tsvwg-iana-ports-04.xml
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<rfc category="bcp" docName="draft-ietf-tsvwg-iana-ports-04"
ipr="pre5378Trust200902" updates="2780, 2782, 3828, 4340, 4960">
<front>
<title abbrev="Port Number and Service Name Procedures">Internet Assigned
Numbers Authority (IANA) Procedures for the Management of the Transport
Protocol Port Number and Service Name Registry</title>
<!-- AUTHORS ALPHABETICAL -->
<!--
<author fullname="Stuart Cheshire" initials="S." surname="Cheshire">
<organization abbrev="Apple">Apple Inc.</organization>
<address>
<postal>
<street>1 Infinite Loop</street>
<code>95014</code>
<city>Cupertino</city>
<region>CA</region>
<country>USA</country>
</postal>
<phone>+1 408 974 3207</phone>
<email>cheshire@apple.com</email>
</address>
</author>
-->
<author fullname="Michelle Cotton" initials="M." surname="Cotton">
<organization abbrev="ICANN">Internet Corporation for Assigned Names and
Numbers</organization>
<address>
<postal>
<street>4676 Admiralty Way, Suite 330</street>
<code>90292</code>
<city>Marina del Rey</city>
<region>CA</region>
<country>USA</country>
</postal>
<phone>+1 310 823 9358</phone>
<email>michelle.cotton@icann.org</email>
<uri>http://www.iana.org/</uri>
</address>
</author>
<author fullname="Lars Eggert" initials="L." surname="Eggert">
<organization abbrev="Nokia">Nokia Research Center</organization>
<address>
<postal>
<street>P.O. Box 407</street>
<code>00045</code>
<city>Nokia Group</city>
<country>Finland</country>
</postal>
<phone>+358 50 48 24461</phone>
<email>lars.eggert@nokia.com</email>
<uri>http://research.nokia.com/people/lars_eggert/</uri>
</address>
</author>
<!--
<author fullname="Allison Mankin" initials="A." surname="Mankin">
<organization abbrev="Johns Hopkins Univ.">Johns Hopkins
University</organization>
<address>
<postal>
<street>4102 Wilson Boulevard</street>
<city>Arlington</city>
<region>VA</region>
<code>22230</code>
<country>USA</country>
</postal>
<phone>+1 301 728 7199</phone>
<email>mankin@psg.com</email>
<uri>http://www.psg.com/~mankin/</uri>
</address>
</author>
-->
<author fullname="Joe Touch" initials="J." surname="Touch">
<organization>USC/ISI</organization>
<address>
<postal>
<street>4676 Admiralty Way</street>
<code>90292</code>
<city>Marina del Rey</city>
<region>CA</region>
<country>USA</country>
</postal>
<phone>+1 310 448 9151</phone>
<email>touch@isi.edu</email>
<uri>http://www.isi.edu/touch</uri>
</address>
</author>
<author fullname="Magnus Westerlund" initials="M." surname="Westerlund">
<organization>Ericsson</organization>
<address>
<postal>
<street>Torshamsgatan 23</street>
<city>Stockholm</city>
<code>164 80</code>
<country>Sweden</country>
</postal>
<phone>+46 8 719 0000</phone>
<email>magnus.westerlund@ericsson.com</email>
</address>
</author>
<date year="2010"/>
<area>Transport Area</area>
<workgroup>Transport Area Working Group</workgroup>
<keyword>IANA</keyword>
<keyword>transport</keyword>
<keyword>ports</keyword>
<keyword>port numbers</keyword>
<keyword>allocation</keyword>
<keyword>procedures</keyword>
<abstract>
<t>This document defines the procedures that the Internet Assigned
Numbers Authority (IANA) uses when handling registration and other
requests related to the transport protocol port number and service name
registry. It also discusses the rationale and principles behind these
procedures and how they facilitate the long-term sustainability of the
registry.</t>
<t>This document updates IANA's procedures by obsoleting Sections 8
and 9.1 of the IANA allocation guidelines [RFC2780], it updates
the IANA allocation procedures for UDP-Lite [RFC3828], DCCP [RFC4340] and SCTP [RFC4960],
it updates the DNS SRV specification [RFC2782] to clarify what a service name
is and how it is registered.</t>
</abstract>
</front>
<middle>
<section anchor="intro" title="Introduction">
<t>For many years, the allocation and registration of new port number
values and service names for use with the Transmission Control Protocol
(TCP) <xref target="RFC0793"/> and the User Datagram Protocol (UDP)
<xref target="RFC0768"/> have had less than clear guidelines. New transport
protocols have been added - the Stream Control Transmission Protocol
(SCTP) <xref target="RFC4960"/> and the Datagram Congestion Control
Protocol (DCCP) <xref target="RFC4342"/> - and new mechanisms like DNS SRV
records <xref target="RFC2782"/> have been developed, each with separate
registries and separate guidelines. The community recognized the need for
additional procedures beyond just assignment; notably modification,
revocation, and release.</t>
<t>A key factor of this procedural streamlining is to establish
identical registration procedures for all IETF transport protocols. This
document brings the IANA procedures for 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 all transport protocols, including
those not yet defined.</t>
<t>In addition to detailing the IANA procedures for the initial
assignment of port numbers and service names, this document also
specifies post-assignment procedures that until now have been handled in
an ad hoc manner. These include procedures to de-register a port number
that is no longer in use, to re-use a port number allocated for one
application that is no longer in use for another application, and the
procedure by which IANA can unilaterally revoke a prior port number
registration. <xref target="iana-procedures"/> discusses the specifics
of these procedures and processes that requesters and IANA follow for
all requests for all current and future transport protocols.</t>
<t>It is important to note that ownership of registered port numbers and
service names remains with IANA. For protocols developed by IETF working
groups, IANA now also offers a method for the "early" assignment of port
numbers and service names <xref target="RFC4020"/>, as described in
<xref target="registration"/>.</t>
<t>This document updates IANA's procedures for UDP and TCP port numbers
by obsoleting Sections 8 and 9.1 of the IANA allocation guidelines
<xref target="RFC2780"/>. (Note that different sections of the IANA
allocation guidelines, relating to the protocol field values in IPv4
header, were also updated in February 2008 <xref target="RFC5237"/>.)
This document also updates the IANA allocation procedures for DCCP
<xref target="RFC4340"/> and SCTP <xref target="RFC4960"/>.</t>
<t>The Lightweight User Datagram Protocol (UDP-Lite) <xref target="RFC5237"/>
shares the port space with UDP. The UDP-Lite specification says:
"UDP-Lite 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 of the UDP-Lite procedures.</t>
<t>This document also clarify what a service name is and how it
is registered. This will impact the DNS SRV specification,
because that specification merely makes a brief mention
that the symbolic names of services are defined in "Assigned Numbers"
<xref target="RFC1700"/>, without stating to which section of that
230-page document it refers. The DNS SRV specification may have been
referring 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 other section. Furthermore, "Assigned Numbers" is now obsolete
<xref target="RFC3232"/> and has now been replaced by on-line registries
<xref target="PORTREG"/><xref target="PROTSERVREG"/>. There are
additional updates and clarifications on how DNS SRV utilize the
Service name registry created in this document in
"Clarification of DNS SRV Owner Names"
<xref target="I-D.gudmundsson-dnsext-srv-clarify"/>.</t>
</section>
<section anchor="motivation" title="Motivation">
<t>Information about the registration procedures for the
port registry has existed in three locations: the forms for requesting port
number registrations on the IANA web site <xref target="SYSFORM"/>
<xref target="USRFORM"/>, an introductory text section in the file
listing the port number registrations themselves
<xref target="PORTREG"/>,
and two brief sections of the IANA Allocation Guidelines
<xref target="RFC2780"/>.</t>
<t>Similarly, the procedures surrounding service names have been
historically unclear. Service names were originally created as mnemonic
identifiers for port numbers without a well-defined syntax, beyond the
14-character limit mentioned on the IANA website
<xref target="SYSFORM"/> <xref target="USRFORM"/>.
Even that length limit has not been consistently applied, and some
assigned service names are 15 characters long. When service
identification via DNS SRV RRs was introduced, the
requirement by IANA to only assign service names and port numbers in
combination, led to the creation of an ad hoc service name registry
outside of the control of IANA <xref target="SRVREG"/>.</t>
<!--
This text duplicates what's said elsewhere in the document.
I also don't think that RFC 0952 (DOD INTERNET HOST TABLE SPECIFICATION)
sheds any light on this issue. -- SC
<t>It has also been historically unclear if the "name" entries registered
in the "Protocol and Service Names Registry" <xref target="PROTSERVREG"/>
can be used as service names. <xref target="RFC0952"/> defines the names
in that registry as either service names or protocol names. It is likely
that these names has been interpreted as being valid service names and
consequently have been used, e.g., in SRV records. This motivates why
this document merges the 166 protocol and service names defined in that
registry into the port number registry <xref target="PORTREG"/>.</t>
-->
<t>This document aggregates all this scattered information into a single
reference that aligns and clearly defines the management procedures for
both port numbers and service names. It gives more detailed guidance to
prospective requesters of ports and service names than the existing
documentation, and it streamlines the IANA procedures for the management
of the registry, so that management requests can complete in a timely
manner.</t>
<t>This document defines rules for registration of service names without
associated port numbers, for such usages as DNS SRV records
<xref target="RFC2782"/>, which was
not possible under the previous IANA procedures. The document
also merges service name registrations from the non-IANA ad hoc registry
<xref target="SRVREG"/> and from the the IANA "Protocol and Service
Names" registry <xref target="PROTSERVREG"/> into the IANA "Port and
Service Name" registry <xref target="PORTREG"/>, which from here on is
the single authoritative registry for service names and port numbers.</t>
<t>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 stewards of
the port number registry. TCP and UDP have been a remarkable success
over the last decades. Thousands of applications and application-level
protocols have registered ports and service names for their use, and
there is every reason to believe that this trend will continue into the
future. It is hence extremely important that management of the registry
follow principles that ensure its long-term usefulness as a shared
resource. <xref target="principles"/> discusses these principles
in detail.
<!-- Commented this out until we know what Joe's doc will actually say.
Guidelines for users seeking port numbers and/or service names, as well
as a detailed history of the port number registry and alternate means for
coordinating host agreement on service-to-port-number mappings, is
provided in a <xref target="I-D.touch-tsvwg-port-guidelines">companion
document</xref>.-->
</t>
</section>
<section title="Background">
<t>The Transmission Control Protocol (TCP)
<xref target="RFC0793"/> and the User Datagram Protocol (UDP)
<xref target="RFC0768"/> have enjoyed a remarkable success over the
decades as the two most widely used transport protocols on the Internet.
They have relied on the concept of "ports" as logical entities for
Internet communication. Ports serve two purposes: first, they provide a
demultiplexing identifier to differentiate transport sessions between
the same pair of endpoints, and second, they may also identify the
application protocol and associated service to which processes bind.
Newer transport protocols, such as the Stream Control Transmission
Protocol (SCTP) <xref target="RFC4960"/> and the Datagram
Congestion Control Protocol (DCCP) <xref target="RFC4342"/> have
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
<xref target="RFC3828"/>, a variant of UDP).</t>
<t>Port numbers are the original and most widely used means for
application and service identification on the Internet. Ports are 16-bit
numbers, and the combination of source and destination port numbers
together with the IP addresses of the communicating end systems uniquely
identifies a session of a given transport protocol. Port numbers are
also known by their corresponding service names such as "telnet" for
port number 23 and "http" (and the "www" alias) for port number 80.</t>
<t>Hosts running services, hosts accessing services on other hosts, and
intermediate devices (such as firewalls and NATs) that restrict services
need to agree on which service corresponds to a particular destination
port. Although this is ultimately a local decision with meaning only
between the endpoints of a connection, it is common for many services
to have a default port upon which those servers usually listen,
when possible, and these ports are recorded by the Internet
Assigned Numbers Authority (IANA) through the port number registry
<xref target="PORTREG"/>.</t>
<t>Over time, the assumption that a particular port number necessarily
implies a particular service may become less true. For example, multiple
instances of the same service on the same host cannot 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
external side of the NAT gateway, whether using static port
mappings configured by hand by the user, or dynamic port
mappings configured automatically using a port mapping protocol
<xref target="I-D.cheshire-nat-pmp">NAT Port Mapping Protocol (NAT-PMP)
</xref> or <xref target="IGD">Internet Gateway Device (IGD)</xref>.</t>
<!--
<t><list style="symbols">
<t>When different background applications on a single computer each
export a web-based user interface, (e.g. as done by the Common Unix
Printing System <xref target="CUPS"/>) they cannot all get TCP
port 80, especially if that computer is also hosting a conventional
web site on TCP port 80. Consequently, a single host may have
several different processes all answering HTTP requests of various
kinds, on ports other than port 80.</t>
<t>When different users are running multiple copies of the same
application on a single computer, multiple instances of the
application cannot listen on the same port at the same time.
Consequently, applications of this kind need to be programmed to
expect that they may not always be able to get the port they want,
and may have to listen on an alternative port instead.</t>
<t>When different computers in a home are using a NAT gateway to
share a single IP address, the computers can request that the NAT
gateway create port mappings to enable them to receive inbound
connections <xref target="I-D.cheshire-nat-pmp"/><xref
target="IGD"/>, but they can't all get the same external port
at the same time. Consequently, some applications on some of those
computers may be receiving inbound connections on port other than
the port usually used for the service in question. As ISPs begin to
deploy large-scale NAT, sharing a single IP address between multiple
homes, it is likely to become even more common to have applications
receiving connections on dynamically allocated ports.</t>
</list></t>
-->
<t>Applications either use numeric port numbers directly, look up port
numbers based on service names via system calls such as getservbyname()
on UNIX, look up port numbers by performing queries for DNS SRV records
<xref target="RFC2782"/><xref target="I-D.cheshire-dnsext-dns-sd"/>
or determine port numbers in a variety of other ways
like the TCP Port Service Multiplexer (TCPMUX)
<xref target="RFC1078"/>.</t>
<t>Designers of applications and application-level protocols may apply
to IANA for an assigned port number and service name for a specific
application, and may - after successful registration - assume that no
other application will use that port number or service name for its
communication sessions. Alternatively, application designers may also
ask for only an assigned service name, if their application does not
require a fixed port number. The latter alternative is encouraged when
possible, in order to conserve the more limited port number space. This
includes, for example, applications that use DNS SRV records to look up
port numbers at runtime.</t>
<!--
There have been many proposals over the years for putting names
instead of numbers into the TCP header. I think it's
inappropriate to list one such proposal here if we're not going
to list all the others too.
, or transports that use service names not coupled
to port numbers, e.g., TCP portnames
<xref target="I-D.touch-tcp-portnames"/>
-->
</section>
<section anchor="term" title="Conventions Used in this Document">
<t>The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in
this document are to be interpreted as described in RFC 2119
<xref target="RFC2119"/>.</t>
</section>
<section title="Service Names">
<t>Service names are the unique key in the Port and Service Name
registry. This unique symbolic name for a service may also be used for
other purposes, such as in <xref target="RFC2782">DNS SRV records</xref>.
Within the registry, this unique key ensures that different services can
be unambiguously distinguished, thus preventing name collisions and
avoiding confusion about who is the administrative contact for a particular
entry.</t>
<t>For each service name, there may exist zero or more associated port
number assignments. A port number assignment associated with a service
name contains the transport protocol, port number and possibly additional
data, such as a DCCP service code.</t>
<t>There may be more than one service name associated with a particular
transport protocol and port. This SHOULD only occur when all such
service names are aliases for the same service, such as with "http" and
"www". In such cases, one of the service names MUST be designated primary,
for use with mechanisms such as DNS SRV Records <xref target="RFC2782"/>,
and the others MUST be designated as aliases of the primary service name.
This is necessary so that all clients and servers using a service
discovery mechanism use a consistent name by which to refer to a
given service. Otherwise, if a server were to advertise that it
supports the "www" service, and a client were to seek instances of
the "http" service, that client would fail to discover that server,
defeating the purpose of having a service discovery mechanism.</t>
<t>Service names are assigned on a "first come, first served" basis, as
described in <xref target="registration"/>. Names should be brief and
informative, avoiding words or abbreviations that are redundant in the
context of the registry (e.g., "port", "service", "protocol", etc.) Names
referring to discovery services, e.g., using multicast or broadcast to
identify endpoints capable of a given service, SHOULD use an easily
identifiable suffix (e.g., "-disc").</t>
<section anchor="sec-syntax" title="Service Name Syntax">
<t> Valid service names MUST contain only these US-ASCII
<xref target="ANSI.X3-4.1986"/> characters: letters from A to Z
and a to z, digits from 0 to 9, and hyphens ("-", ASCII 0x2D or
decimal 45). They MUST be at least one character and no more than
fifteen characters long, MUST NOT begin or end with a hyphen, and
MUST NOT consist of only digits (in order to be distinguishable
from port numbers, which are typically written as all digits). </t>
<t> The service name syntax MAY be used to validate a service name
string, but MUST NOT be used for any other purpose (e.g.,
delineation). Any system that includes a service name inside a
longer string is itself responsible for delineating the service
name. Such systems MUST NOT rely on the syntax of a service name
alone for such delineation. </t>
<t> The syntax defined in <xref target="RFC5234">ABNF</xref>: </t>
<figure>
<artwork><![CDATA[
SERVICE-NAME = ( ALPHA / *( [HYPHEN] ALPHANUM ) )
/ (1*DIGIT ( (HYPHEN ALPHANUM) | ALPHA) *([HYPHEN] ALPHANUM) )
ALPHANUM = ALPHA | DIGIT ; A-Z, a-z, 0-9
HYPHEN = %x2d ; "-"
ALPHA = <See RFC 5234>
DIGIT = <See RFC 5234>
]]></artwork>
</figure>
</section>
<section title="Service Name Usage in DNS SRV Records">
<t> The DNS SRV specification <xref target="RFC2782"/> requests
that the Service Label part of the owner name of DNS SRV records
includes a "Service" element, defined to be "the symbolic name of
the desired service", but did not state precisely which part of
the IANA database (i.e. STD 2 when RFC 2782 was written) serves as
a registry for standard service names.</t>
<t> This document clarifies that the Service Label MUST be a
service name as defined herein. The service name SHOULD be
registered with IANA and recorded in the Service Names and Port
Numbers registry <xref target="PORTREG"/>. This is needed to
ensure that only a single registry of Service Names exists and
name collisions can be avoided in the future.</t>
<t> The details of the use of Service Names from <xref
target="PORTREG"/> in SRV Service Labels are specified in <xref
target="RFC2782"/> and the documents updating or replacing that
specification (see the companion document
<xref target="I-D.gudmundsson-dnsext-srv-clarify"/> for more
information).</t>
<t> The details of how applications make use of DNS SRV should be
specified in the documentation set of the application/service. In
the absense of such specification, prospective clients of a given
service should not assume the existence of SRV RRs for this
service or, if they have indications that this will be the case
(e.g., by configuration), must assume the unextended naming scheme
from <xref target="RFC2782"/> for service discovery with DNS SRV,
i.e., the Service Label is constructed from the Service Name
registered in <xref target="PORTREG"/> by prepending a single
underscore character ("_").</t>
</section>
</section>
<section anchor="types" title="Port Number Ranges">
<t>TCP, UDP, UDP-Lite, SCTP and DCCP use 16-bit namespaces for
their port number registries. The port registries for all these
transport protocols are subdivided into three ranges of numbers, and
<xref target="variances"/> describes the IANA procedures for each
range in detail:
<list style="symbols">
<t>the Well Known Ports, also known as the System Ports, from 0-1023
(assigned by IANA)</t>
<t>the Registered Ports, also known as the User Ports, from
1024-49151 (assigned by IANA)</t>
<t>the Dynamic Ports, also known as the Private Ports, from
49152-65535 (never assigned)</t>
</list>
</t>
<t>Of the assignable port ranges (Well Known and Registered, i.e., port
numbers 0-49151), individual port numbers are in one of three states at
any given time:</t>
<t>
<list style="symbols">
<t>Assigned: Assigned port numbers are currently allocated to the
service indicated in the registry.</t>
<t>Unassigned: Unassigned port numbers are currently available for
assignment upon request, as per the procedures outlined in this
document.</t>
<t>Reserved: Reserved port numbers are not available for regular
assignment; they are "assigned to IANA" for special purposes.
Reserved port numbers include values at the edges of each range,
e.g., 0, 1023, 1024, etc., which may be used to extend these ranges
or the overall port number space in the future.</t>
</list>
</t>
<t>In order to keep the size of the registry manageable, IANA typically
only records the Assigned and Reserved port numbers and service names in
the registry. Unassigned values are typically not explicitly listed.</t>
<t>As a data point, when this document was written, approximately 76% of
the TCP and UDP Well Known Ports were assigned, and approximately 9% of
the Registered Ports were assigned. (As noted, Dynamic Ports are never
assigned.)</t>
<section anchor="udptcpexp"
title="Port Numbers and Service Names for Experimentation">
<t>Of the Well Known ports, two TCP and UDP port numbers (1021 and
1022), together with their respective service names ("exp1" and
"exp2"), have been assigned for experimentation with new applications
and application-layer protocols that require a port number in the
assigned ports ranges <xref target="RFC4727"/>.</t>
<t>Please refer to Sections 1 and 1.1 of "Assigning Experimental and
Testing Numbers Considered Useful" <xref target="RFC3692"/> for
how these experimental port numbers are to be used.
<!-- I still think this could be useful to explicitly repeat - Lars
Specifically, they
SHOULD only be used for local experiments in controlled environments,
and they SHOULD NOT be used on the global Internet. Many new
applications and application-layer protocols can be experimented with
without requiring a port in the Well Known or Registered ports range,
by using port numbers in the Dynamic Ports range. -->
</t>
<t>This document registers the same two port numbers and service names
for experimentation with new application-layer protocols over SCTP and
DCCP in <xref target="sctpdccpexp"/>.</t>
<t>Unfortunately, it can be difficult to limit access to these ports.
Users SHOULD take measures to ensure that experimental ports are
connecting to the intended process. For example, users of these
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 byte-stream (e.g., TCP), which is used to confirm that the port is
being used as intended. Such confirmation of intended use is
especially important when these ports are associated with privileged
(e.g., system or administrator) processes.</t>
</section>
</section>
<section anchor="principles"
title="Principles for Port Number and Service Name Registry Management">
<t>Management procedures for the port number and service name registry
include allocation of port numbers and service names upon request, as
well as coordination of information about existing allocations. The
latter includes maintaining contact and description information about
assignments, revoking abandoned assignments, and redefining assignments
when needed. Of these procedures, port number allocation is most
critical, in order to continue to conserve the remaining port
numbers.</t>
<t>As noted earlier, only ~9% of the Registered Port space is currently
assigned. The current rate of assignment is approximately 400 ports/year,
and has remained linear for the past 8 years. At that rate, if similar
conservation continues, this resource will sustain another 85 years of
assignment - without the need to resort to reassignment of released
values or revocation. Note that the namespace available for service names
is even larger, which allows for a simpler management procedures.</t>
<section title="Past Principles">
<t>Before the publication of this document, the principles of port number
and service name management followed a few mostly-undocumented
guidelines. They are recorded here for historical purposes, and this
document updates them in <xref target="upprinc"/>. These principles
were:</t>
<t>
<list style="symbols">
<t>TCP and UDP ports were simultaneously allocated when either was
requested</t>
<t>Port numbers were the primary allocation; service names were
informative only, and did not have a well-defined syntax</t>
<t>Port numbers were conserved informally, and sometimes
inconsistently (e.g., some services were allocated ranges of many
port numbers even where not strictly necessary)</t>
<t>SCTP and DCCP port number and service name registries were
managed separately from the TCP/UDP registries</t>
<t>Service names could not be assigned in the ports registry without
assigning a corresponding port number at the same time</t>
</list>
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.</t>
<!--
<t>Port numbers are intended to identify a service and
enable process demultiplexing at an endpoint; uses beyond
those basic requirements should be avoided
<xref target="I-D.touch-tsvwg-port-guidelines"/>. This
document also focuses on service names as a unique identifier,
to increase the space available (from 4 bytes to 14), and to
enable their use in the absence of corresponding port number
assignments.
<cref source="Lars" anchor="incr-space">I don't understand
where the "extend from 4 bytes to 14" bit comes
from.</cref></t>
-->
</section>
<section title="Updated Principles" anchor="upprinc">
<t>This section summarizes the basic principles by which IANA handles the
Port and Service Name registry, and attempts
to conserve the port number space. This description is intended to
inform applicants requesting service names and port numbers. IANA decisions are not
required to be bound to these principles, however; other factors may
come into play, and exceptions may occur where deemed in the best
interest of the Internet.</t>
<t>IANA will begin assigning service names that do not request a
corresponding port number allocation under a simple "First Come,
First Served" policy <xref target="RFC5226"/>.
IANA MAY, at its discretion, refer service name requests to
"Expert Review" in cases of mass registrations or other
situations where IANA believes expert review is advisable.</t>
<t>The basic principle of port number registry management is to
conserve use of the port space where possible. Extensions to support
larger port number spaces would require changing many core protocols
of the current Internet in a way that would not be backward compatible
and interfere with both current and legacy applications. To help
ensure this conservation the policy for any registration request for
port number allocations uses the "Expert Review" policy <xref target="RFC5226"/>.</t>
<t>Conservation of the port number space is required because this
space is a limited resource, applications are expected to participate
in the traffic demultiplexing process where feasible. The port numbers
are expected to encode as little information as possible that will
still enable an application to perform further demultiplexing by
itself. In particular:</t>
<t>
<list style="symbols">
<t>IANA will allocate only one assigned port number per service or application</t>
<t>IANA will allocate only one assigned port number for all versions of a service
(e.g., running the service with or without a security
mechanism, or for updated variants of a service)</t>
<t>IANA will allocate only one assigned port number for all different types of
device using or participating in the same service</t>
<t>IANA will allocate port numbers only for the transport protocol(s)
(if any) explicitly named in an registration request</t>
<t>IANA may recover unused port numbers, via the new procedures of
de-registration, revocation, and transfer</t>
</list>
A given service is expected to further demultiplex messages where
possible. For example, applications and protocols are expected to
include in-band version information, so that future versions of the
application or protocol can share the same allocated port.
Applications and protocols are also expected to be able to efficiently
use a single allocated port for multiple sessions, either by
demultiplexing multiple streams within one port, or using the
allocated port to coordinate using dynamic ports for subsequent
exchanges (e.g., in the spirit of FTP <xref target="RFC0959"/>).</t>
<!-- Removed until doc is available:
These principles of port conservation are explained in
<xref target="I-D.touch-tsvwg-port-guidelines"/>.
That document explains in further detail how -->
<t>Ports are used in various ways, notably:</t>
<t>
<list style="symbols">
<t>as endpoint process identifiers</t>
<t>as application protocol identifiers</t>
<t>for firewall filtering purposes</t>
</list>
The process and protocol identifier use suggests that anything a
single process can demultiplex, or that can be encoded into a single
protocol, should be. The firewall filtering use suggests that some
uses that could be multiplexed or encoded must be separated to
allow for firewall management. Note that this latter use is much less
sound, because port numbers have meaning only for the two endpoints
involved in a connection, and drawing conclusions about the service
that generated a given flow based on observed port numbers is
not always reliable.
<!-- (again, as discussed in detail in
<xref target="I-D.touch-tsvwg-port-guidelines"/>).-->
Further, previous separation of protocol variants based on security
capabilities (e.g., HTTP on port 80 vs. HTTPS on port 443) is not
recommended for new protocols, because all should be security-capable
and capable of negotiating the use of security in-band.</t>
<t>IANA will begin assigning protocol numbers for only those transport
protocols explicitly included in a registration request. This ends 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 only
one of these transport protocols. The new allocation procedure
conserves resources by allocating a port number to an application for
only those transport protocols (TCP, UDP, SCTP and/or DCCP) it actually
uses. The port number will be marked as Reserved - instead of Assigned
- in the port number registries of the other transport protocols. When
applications start supporting the use of some of those additional
transport protocols, their implementors MUST request IANA to convert
the reservation into an assignment. An application MUST NOT assume
that it can use a port number assigned to it for use with one
transport protocol with another transport protocol without asking IANA
to convert the reservation into an assignment.</t>
<t>When the available pool of unassigned address has run out in a port range, it will be
necessary for IANA to consider the Reserved ports for assignment. This
is part of the motivation to not automatically assigning ports for other
transport protocols than the requested ones. This will allow more ports
to be available for assignment at that point. It also shows the importance
to register the transport protocols that are in fact used.</t>
<t>Conservation of port numbers is improved by procedures that allow
previously allocated port numbers to become Unassigned, either through
de-registration or through revocation, and by a procedure that lets
application designers transfer an allocated but unused port number to
a new application. <xref target="iana-procedures"/> describes
these procedures, which so far were undocumented. Port number
conservation is also improved by recommending that applications that
do not require an allocated port chose this option and register only a
service name.</t>
</section>
<section anchor="variances"
title="Variances for Specific Port Number Ranges">
<t><xref target="types"/> describes the different port number
ranges. It is important to note that IANA applies slightly different
procedures when managing the different ranges of the port number
registry:
<list style="symbols">
<t>Ports in the Dynamic Ports range (49152-65535) have been
specifically set aside for local and dynamic use and cannot be
registered through IANA. Applications may simply use them for
communication without any sort of registration. On the other hand,
applications MUST NOT assume that a specific port number in the
Dynamic Ports range will always be available for communication at
all times, and a port number in that range hence MUST NOT be used
as a service identifier.</t>
<t>Ports in the Registered Ports range (1024-49151) are available
for registration through IANA, and MAY be used as service
identifiers upon successful registration. Because registering a
port number for a specific application consumes a fraction of the
shared resource that is the port number registry, IANA will
require the requester to document the intended use of the port
number. This documentation will be input to the "Expert Review"
allocation procedure <xref target="RFC5226"/>, by which IANA
will have a technical expert review the request to determine
whether to grant the registration. The submitted documentation
MUST explain why using a port number in the Dynamic Ports range is
unsuitable for the given application.</t>
<t>Ports in the Well Known Ports range (0-1023) are also available
for registration through IANA. Because the Well Known Ports range
is both the smallest and the most densely allocated, the requirements
for new allocations are more strict than those for the Registered Ports
range, and will only be granted under the "IETF Review" allocation
procedure <xref target="RFC5226"/>. A request for a Well
Known port number MUST document why using a port number from both
the Registered Ports and Dynamic Ports ranges is unsuitable for
the given application.</t>
</list>
</t>
</section>
</section>
<section anchor="iana-procedures"
title="IANA Procedures for Managing the Port Number and Service Name Registry">
<t>This section describes the process for requests associated with
IANA's management of the port number and service name registry. Such
requests include initial registration, de-registration, re-use, changes
to the service name, as well as updates to the contact information or
description associated with an assignment. Revocation is initiated by
IANA.</t>
<section anchor="registration"
title="Port Number and Service Name Registration">
<t>Registration refers to the allocation of port numbers or service
names to applicants. All such registrations are made from port numbers
or service names that are Unassigned or Reserved at the time of the
allocation. Unassigned numbers and names are allocated as needed, and
without further explanation. Reserved numbers and names are assigned
only after review by IANA and the IETF, and are accompanied by a
statement explaining the reason a Reserved number or name is
appropriate for this action.</t>
<t>When a registration for one or more transport
protocols is approved, the port number for any non-requested transport
protocol(s) will be marked as Reserved. IANA SHOULD NOT assign that
port number to any other application or service until no other port
numbers remain Unassigned in the requested range. The current
administrative contact for a port number MAY register these Reserved port
numbers for other transport protocols when needed.</t>
<t>Service names, on the other hand, are not tied to a specific
transport protocol, and registration requests for only a service name
(but not a port number) allocate that service name for use with all
transport protocols.</t>
<t><vspace blankLines="11" />A port number or service name registration request contains
some or all of the following information:</t>
<t>
<list style="empty">
<t>
Registration Administrative Contact (REQUIRED)<vspace />
Registration Technical Contact (REQUIRED)<vspace />
Service Name (REQUIRED)<vspace />
Port Number (OPTIONAL)<vspace />
Transport Protocol(s) (REQUIRED if port number requested)<vspace />
Service Code (only REQUIRED for DCCP)<vspace />
Description (REQUIRED)<vspace />
Reference (REQUIRED)
</t>
</list>
</t>
<t>
<list style="symbols">
<t>Registration Administrative Contact:
Name and email address of the administrative contact for the
registration. This is REQUIRED. The name of the administrative contact
identifies the organization, company, or individual who is responsible
for the registration. Registrations done through
IETF-published RFCs, the administrative contact will be the
IETF and not the technical contact persons.</t>
<t>Registration Technical Contact: Name and email address of the
technical contact person for the registration. This is REQUIRED.
For individuals, this is the same as the
Registration Administrative Contact; for
organizations, this is a point of contact at that organization.
Additional address information MAY be provided. For registrations
done through IETF-published RFCs, one or more technical contact
persons SHALL be provided.</t>
<t>Service Name: A desired unique service name for the
service associated with the registration request MUST be
provided, for use in various service selection and discovery
mechanisms (including, but not limited to, DNS SRV records
<xref target="RFC2782"/>). The name MUST be compliant with
the syntax defined in <xref target="sec-syntax"/>. In order
to be unique, they MUST NOT be identical to any currently
registered service names in the IANA registry <xref
target="PORTREG"/>. Service names are case-insensitive; they
may be provided and entered into the registry with mixed
case (e.g., for clarity), but for the purposes of
comparison, the case is ignored.</t>
<t>Port Number: If assignment of a port number is desired, either
the currently Unassigned port number the requester suggests for
allocation, or the text "ANY", MUST be provided. If only a service
name is to be assigned, this field MUST be empty. If a specific port
number is requested, IANA is encouraged to allocate the
requested number. If the text "ANY" is specified, IANA will choose
a suitable number from the Registered Ports range. Note that the
applicant MUST NOT use the requested port prior to the completion
of the registration<!-- or the IETF will be very very cross
and will glare at you in a most disapproving manner-->.</t>
<t>Transport Protocol(s): If assignment of a port number is
desired, the transport protocol(s) for which the allocation
is requested MUST be provided. This field is currently
limited to one or more of TCP, UDP, SCTP, and DCCP.</t>
<t>Service Code: The request MUST include a desired unique
DCCP service code <xref target="RFC5595"/>
if the registration request includes DCCP as a transport
protocol, and MUST NOT include a requested DCCP service
code otherwise.</t>
<t>Description: A short description of the service associated with
the registration request is REQUIRED. It should avoid all but the
most well known acronyms.</t>
<t>Reference: A description of (or a reference to a document
describing) the protocol or application using this port.
The description must include whether the protocol uses either
broadcast, multicast, or anycast communication.
<vspace blankLines="1"/>
For registrations requesting only a Service Name or a
Service Name and Registered Port, a statement that
the protocol is proprietary and not publicly documented is
also acceptable provided that the above information
regarding use of broadcast, multicast, or anycast is given.
<vspace blankLines="1"/>
For registration requests for a Registered Port, the
registration request MUST explain why a port number in the
Dynamic Ports range is unsuitable for the given application.
<vspace blankLines="1"/>
For registration requests for a Well Known Port, the
registration request MUST explain why a port number in the
Registered Ports or Dynamic Ports ranges is unsuitable,
and a reference to a stable protocol specification document
MUST be provided. For requests from IETF Working Groups,
IANA MAY accept "Early" registration requests referencing a
sufficiently stable Internet Draft instead of a published
Standards-Track RFC <xref target="RFC4020"/>.</t>
</list>
</t>
<t>When IANA receives a registration request containing the above
information requesting a port number, IANA SHALL initiate an "Expert
Review" <xref target="RFC5226"/> in order to determine whether an
assignment should be made. For requests that do not include a
port number, IANA SHOULD assign the service name under a simple
"First Come First Served" policy <xref target="RFC5226"/>.</t>
</section>
<section anchor="deregistration"
title="Port Number and Service Name De-Registration">
<t>The administrative contact of a granted port number assignment can
return the port number to IANA at any time if they no longer have a
need for it. The port number will be de-registered and will be marked
as Reserved. IANA should not re-assign port numbers that have been
de-registered until all other available port numbers in the specific
range have been assigned.</t>
<t>Before proceeding with a port number de-registration, IANA needs to
reasonably establish that the value is actually no longer in use.</t>
<t>Because there is much less danger of exhausting the service name
space compared to the port number space, it is RECOMMENDED that a
given service name remain assigned even after all associated port
number assignments have become de-registered. Under this policy, it will
appear in the registry as if it had been created through a service
name registration request that did not include any port numbers.</t>
<t>On rare occasions, it may still be useful to de-register a service
name. In such cases, IANA will mark the service name as Reserved. IANA
will involve their IESG-appointed expert in such cases.</t>
</section>
<section anchor="reuse" title="Port Number and Service Name Re-Use">
<t>If the administrative contact of a granted port number assignment no
longer have a need for the registered number, but would like to re-use
it for a different application, they can submit a request to IANA to
do so.</t>
<t>Logically, port number re-use is to be thought of as a
de-registration (<xref target="deregistration"/>) followed by an
immediate re-registration (<xref target="registration"/>) of the same
port number for a new application. Consequently, the information that
needs to be provided about the proposed new use of the port number is
identical to what would need to be provided for a new port number
allocation for the specific ports range.</t>
<t>Because there is much less danger of exhausting the service name
space compared to the port number space, it is RECOMMENDED that the
original service name associated with the prior use of the port number
remains assigned, and a new service be created and associated with the
port number. This is again consistent with viewing a re-use request as
a de-registration followed by an immediate re-registration. Re-using
an assigned service name for a different application is NOT
RECOMMENDED.</t>
<t>IANA needs to carefully review such requests before approving them.
In some instances, the Expert Reviewer will determine that the
application that the port number was assigned to has found usage
beyond the original requester, or that there is a concern that it may
have such users. This determination MUST be made quickly. A community
call concerning revocation of a port number (see below) MAY be
considered, if a broader use of the port number is suspected.</t>
</section>
<section anchor="revocation"
title="Port Number and Service Name Revocation">
<t>A port number revocation can be thought of as an IANA-initiated
de-registration (<xref target="deregistration"/>), and has
exactly the same effect on the registry.</t>
<t>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 times, it may be unclear whether a given assigned port number is
still in use somewhere in the Internet. In those cases, IANA must
carefully consider the consequences of revoking the port number, and
SHOULD only do so if there is an overwhelming need.</t>
<t>With the help of their IESG-appointed Expert Reviewer, IANA SHALL
formulate a request to the IESG to issue a four-week community call
concerning the pending port number revocation. The IESG and IANA, with
the Expert Reviewer's support, SHALL determine promptly after the end
of the community call whether revocation should proceed and then
communicate their decision to the community. This procedure typically
involves similar steps to de-registration except that it is initiated
by IANA.</t>
<t>Because there is much less danger of exhausting the service name
space compared to the port number space, revoking service names is NOT
RECOMMENDED.</t>
</section>
<section anchor="transfer"
title="Port Number and Service Name Transfers">
<t>The value of port numbers and service names is defined by their
careful management as a shared Internet resource, whereas enabling
transfer allows the potential for associated monetary exchanges. As a
result, the IETF does not permit port number or service name
assignments to be transferred between parties, even when they are
mutually consenting.</t>
<t>The appropriate alternate procedure is a coordinated
de-registration and registration: The new party requests the port
number or service name via a registration and the previous party
releases its assignment via the de-registration procedure outlined
above.</t>
<t>With the help of their IESG-appointed Expert Reviewer, IANA SHALL
carefully determine if there is a valid technical, operational or
managerial reason to grant the requested new assignment.</t>
</section>
<section title="Maintenance Issues">
<t>In addition to the formal procedures described above, updates to
the Description and Technical Contact information are coordinated by
IANA in an informal manner, and may be initiated by either the
registrant or by IANA, e.g., by the latter requesting an update to
current contact information. (Note that Registration Administrative
Contact cannot be changed; see <xref target="transfer"/> above.)</t>
</section>
</section>
<section anchor="seccons" title="Security Considerations">
<t>The IANA guidelines described in this document do not change the
security properties of UDP, TCP, SCTP, or DCCP.</t>
<t><!-- adapted from http://www.iana.org/assignments/port-numbers -->
Assignment of a port number or service name does not in any way imply an
endorsement of an application or product, and the fact that network
traffic is flowing to or from a registered port number does not mean
that it is "good" traffic, or even that it is used by the assigned
service. Firewall and system administrators should choose how to
configure their systems based on their knowledge of the traffic in
question, not whether there is a port number or service name registered
or not.</t>
<t>Services are expected to include support for security, either as
default or dynamically negotiated in-band. The use of separate port
number or service name assignments for secure and insecure variants of
the same service is to be avoided in order to discourage the deployment
of insecure services.</t>
</section>
<section anchor="ianacons" title="IANA Considerations">
<!-- put all changes from 2780 into this section -->
<t>This document obsoletes Sections 8 and 9.1 of the March 2000 IANA
Allocation Guidelines <xref target="RFC2780"/>.</t>
<!-- This is trivia that belongs in an email messsage, not in a
public document that exists in perpetuity. A year from now what
people will care about is how to register their service, not a
tedious exhaustive history of how it came to be that way.
Lars says: No, it needs to be here, because all IANA actions need
to be described in the document.
-->
<t>Upon approval of this document, IANA is requested to contact the
maintainer of the <xref target="SRVREG"/> registry, in order to
merge the contents of that private registry into the official IANA
registry. It is expected that the contents of
<xref target="SRVREG"/> will at that time be replaced with pointers to
the IANA registry and to this RFC.</t>
<t>IANA is instructed to create a new service name entry in
the port number registry <xref target="PORTREG"/> for any entry in the
"Protocol and Service Names" registry <xref target="PROTSERVREG"/> that
does not already have one assigned.</t>
<section anchor="consistency" title="Service Name Consistency">
<t><xref target="registration"/> defines which character strings
are well-formed service names, which until now had not been clearly
defined. The definition in <xref target="registration"/> was
chosen to allow maximum compatibility of service names with current
and future service discovery mechanisms.</t>
<t>As of August 5, 2009 approximately 98% of the so-called "Short
Names" from existing port number registrations
<xref target="PORTREG"/> meet the rules for legal service names
stated in <xref target="registration"/>, and hence will be used
unmodified.</t>
<t>The remaining approximately 2% of the exiting "Short Names" are not
suitable to be used directly as well-formed service names because they
contain illegal characters such as asterisks, dots, plusses, slashes,
or underscores. All existing "Short Names" conform to the length
requirement of 15 characters or fewer. For these unsuitable "Short
Names", listed in the table below, the service name will be the Short
Name with any illegal characters replaced by hyphens. IANA SHALL add
an entry to the registry giving the new well-formed primary
service name for the existing service, that otherwise duplicates
the original assignment information. In the description field of
this new entry giving the primary service name, IANA SHALL record
that it assigns a well-formed service name for the previous
service and reference the original assignment. In the description
field of the original assignment, IANA SHALL add a note that
this entry is an alias to the new well-formed service name, and
that the old service name is historic, not usable for use with many
common service discovery mechanisms.</t>
<t><vspace blankLines="40" />Names containing illegal characters
to be replaced by hyphens:</t>
<texttable><ttcol/><ttcol/><ttcol/>
<c>914c/g</c>
<c>acmaint_dbd</c>
<c>acmaint_transd</c>
<c>atex_elmd</c>
<c>avanti_cdp</c>
<c>badm_priv</c>
<c>badm_pub</c>
<c>bdir_priv</c>
<c>bdir_pub</c>
<c>bmc_ctd_ldap</c>
<c>bmc_patroldb</c>
<c>boks_clntd</c>
<c>boks_servc</c>
<c>boks_servm</c>
<c>broker_service</c>
<c>bues_service</c>
<c>canit_store</c>
<c>cedros_fds</c>
<c>cl/1</c>
<c>contamac_icm</c>
<c>corel_vncadmin</c>
<c>csc_proxy</c>
<c>cvc_hostd</c>
<c>dbcontrol_agent</c>
<c>dec_dlm</c>
<c>dl_agent</c>
<c>documentum_s</c>
<c>dsmeter_iatc</c>
<c>dsx_monitor</c>
<c>elpro_tunnel</c>
<c>elvin_client</c>
<c>elvin_server</c>
<c>encrypted_admin</c>
<c>erunbook_agent</c>
<c>erunbook_server</c>
<c>esri_sde</c>
<c>EtherNet/IP-1</c>
<c>EtherNet/IP-2</c>
<c>event_listener</c>
<c>flr_agent</c>
<c>gds_db</c>
<c>ibm_wrless_lan</c>
<c>iceedcp_rx</c>
<c>iceedcp_tx</c>
<c>iclcnet_svinfo</c>
<c>idig_mux</c>
<c>ife_icorp</c>
<c>instl_bootc</c>
<c>instl_boots</c>
<c>intel_rci</c>
<c>interhdl_elmd</c>
<c>lan900_remote</c>
<c>LiebDevMgmt_A</c>
<c>LiebDevMgmt_C</c>
<c>LiebDevMgmt_DM</c>
<c>mapper-ws_ethd</c>
<c>matrix_vnet</c>
<c>mdbs_daemon</c>
<c>menandmice_noh</c>
<c>msl_lmd</c>
<c>nburn_id</c>
<c>ncr_ccl</c>
<c>nds_sso</c>
<c>netmap_lm</c>
<c>nms_topo_serv</c>
<c>notify_srvr</c>
<c>novell-lu6.2</c>
<c>nuts_bootp</c>
<c>nuts_dem</c>
<c>ocs_amu</c>
<c>ocs_cmu</c>
<c>pipe_server</c>
<c>pra_elmd</c>
<c>printer_agent</c>
<c>redstorm_diag</c>
<c>redstorm_find</c>
<c>redstorm_info</c>
<c>redstorm_join</c>
<c>resource_mgr</c>
<c>rmonitor_secure</c>
<c>rsvp_tunnel</c>
<c>sai_sentlm</c>
<c>sge_execd</c>
<c>sge_qmaster</c>
<c>shiva_confsrvr</c>
<c>sql*net</c>
<c>srvc_registry</c>
<c>stm_pproc</c>
<c>subntbcst_tftp</c>
<c>udt_os</c>
<c>universe_suite</c>
<c>veritas_pbx</c>
<c>vision_elmd</c>
<c>vision_server</c>
<c>wrs_registry</c>
<c>z39.50</c>
</texttable>
<t>Following the example set by the "application/whoispp-query"
MIME Content-Type <xref target="RFC2957"/>, the service name for
"whois++" will be "whoispp".</t>
</section>
<section anchor="sctpdccpexp"
title="Port Numbers for SCTP and DCCP Experimentation">
<t>Two Well Known UDP and TCP ports, 1021 and 1022, have been reserved
for experimental use <xref target="RFC4727"/>. This document registers
the same port numbers for SCTP and DCCP, and also instructs IANA to
automatically register these two port numbers for any new transport
protocol that will in the future share the port number namespace.</t>
<t>Note that these port numbers are meant for temporary
experimentation and development in controlled environments. Before
using these port numbers, carefully consider the advice in
<xref target="udptcpexp"/> in this document, as well as in Sections 1
and 1.1 of "Assigning Experimental and Testing Numbers Considered
Useful" <xref target="RFC3692"/>. Most importantly, application
developers must request a permanent port number assignment from IANA
as described in <xref target="registration"/> before any kind of
non-experimental deployment.</t>
<texttable><ttcol/><ttcol/>
<c>Registration Administrative Contact</c> <c>IETF <iesg@ietf.org></c>
<c>Registration Technical Contact</c> <c>IESG <iesg@ietf.org></c>
<c>Service Name</c> <c>exp1</c>
<c>Port Number</c> <c>1021</c>
<c>Transport Protocol</c> <c>SCTP, DCCP</c>
<c>Description</c> <c>RFC3692-style Experiment 1</c>
<c>Reference</c> <c>[RFCyyyy]</c>
</texttable>
<texttable><ttcol/><ttcol/>
<c>Registration Administrative Contact</c> <c>IETF <iesg@ietf.org></c>
<c>Registration Technical Contact</c> <c>IESG <iesg@ietf.org></c>
<c>Service Name</c> <c>exp2</c>
<c>Port Number</c> <c>1022</c>
<c>Transport Protocol</c> <c>SCTP, DCCP</c>
<c>Description</c> <c>RFC3692-style Experiment 2</c>
<c>Reference</c> <c>[RFCyyyy]</c>
</texttable>
<t>[RFC Editor Note: Please change "yyyy" to the RFC number allocated
to this document before publication.]</t>
</section>
<section anchor="dccp" title="Updates to DCCP Registries">
<t>This document updates the IANA allocation procedures for the DCCP
Port Number and DCCP Service Codes Registries
<xref target="RFC4340"/>.</t>
<section title="DCCP Service Code Registry">
<t>Service Codes are allocated first-come-first-served according to
Section 19.8 of the DCCP specification <xref target="RFC4340"/>.
This document updates that section by extending the guidelines given
there in the following ways:</t>
<t>
<list style="symbols">
<t>IANA MAY assign new Service Codes without seeking Expert
Review using their discretion, but SHOULD seek expert review if
a request seeks more than five Service Codes.</t>
<t>IANA should feel free to contact the DCCP Expert Reviewer
with questions on any registry, regardless of the registry
policy, for clarification or if there is a problem with a
request <xref target="RFC4340"/>.</t>
</list>
</t>
</section>
<section title="DCCP Port Numbers Registry">
<t>The DCCP ports registry is defined by Section 19.9 of the DCCP
specification <xref target="RFC4340"/>. Allocations in this registry
require prior allocation of a Service Code. Not all Service Codes
require IANA-registered ports. This document updates that section by
extending the guidelines given there in the following way:</t>
<t>
<list style="symbols">
<t>IANA should normally assign a value in the range 1024-49151
to a DCCP server port. IANA allocation requests to allocate port
numbers in the Well Known Ports range (0 through 1023), require
an "IETF Review" <xref target="RFC5226"/> prior to allocation by
IANA <xref target="RFC4340"/>.</t>
<t>IANA MUST NOT allocate a single Service Code value to more
than one DCCP server port.</t>
<t>The set of Service Code values associated with a DCCP server
port should be recorded in the ports registry.</t>
<t>A request for additional Service Codes to be associated with
an already allocated Port Number requires Expert Review. These
requests will normally be accepted when they originate from the
contact associated with the port registration. In other cases,
these applications will be expected to use an unallocated port,
when this is available.</t>
</list>
</t>
<t>The DCCP specification <xref target="RFC4340"/> notes that
a short port name MUST be associated with each DCCP server port that
has been registered. This document requires that this name MUST be
unique.</t>
</section>
</section>
</section>
<section anchor="sec-contributors" title="Contributors">
<t> Stuart Cheshire (cheshire@apple.com), Alfred Hoenes
(ah@tr-sys.de) and Allison Mankin (mankin@psg.com) have contributed text and ideas to this document. </t>
</section>
<section anchor="ack" title="Acknowledgments">
<t>The text in <xref target="dccp"/> is based on a suggestion by
Tom Phelan.</t>
<t>Lars Eggert is partly funded by the Trilogy Project
<xref target="TRILOGY"/>, a research project supported by the European
Commission under its Seventh Framework Program.</t>
</section>
</middle>
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<references title="Normative References">
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<?rfc include="reference.RFC.0793" ?>
<?rfc include="reference.RFC.2119" ?>
<?rfc include="reference.RFC.2780" ?>
<?rfc include="reference.RFC.3828" ?>
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<?rfc include="reference.RFC.5234" ?>
<?rfc include="reference.ANSI.X3-4.1986" ?>
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<references title="Informative References">
<?rfc include="reference.RFC.0959" ?>
<?rfc include="reference.RFC.1078" ?>
<?rfc include="reference.RFC.1700" ?>
<?rfc include="reference.RFC.2782" ?>
<?rfc include="reference.RFC.2957" ?>
<?rfc include="reference.RFC.3232" ?>
<?rfc include="reference.RFC.3692" ?>
<?rfc include="reference.RFC.4342" ?>
<?rfc include="reference.RFC.4960" ?>
<?rfc include="reference.RFC.5237" ?>
<?rfc include="reference.RFC.5595" ?>
<?rfc include="reference.I-D.cheshire-dnsext-dns-sd" ?>
<?rfc include="reference.I-D.cheshire-nat-pmp" ?>
<?rfc include="reference.I-D.gudmundsson-dnsext-srv-clarify" ?>
<!--
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<reference anchor="SYSFORM">
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<author surname="">
<organization/>
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<reference anchor="TRILOGY">
<front>
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<author>
<organization/>
</author>
</front>
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<!--
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<reference anchor="IGD">
<front>
<title>Internet Gateway Device (IGD) V 1.0</title>
<author fullname="UPnP Forum">
<organization>UPnP Forum</organization>
</author>
<date day="12" month="November" year="2001"/>
</front>
</reference>
</references>
</back>
</rfc>
| PAFTECH AB 2003-2026 | 2026-04-23 22:33:15 |