One document matched: draft-ietf-tsvwg-iana-ports-00.xml
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<rfc category="bcp" docName="draft-ietf-tsvwg-iana-ports-00" ipr="full3978"
updates="2780, 4340">
<front>
<title abbrev="IANA Port Number Space Procedures">IANA Procedures for the
Transport Protocol Port Number Space</title>
<!-- AUTHORS ALPHABETICAL -->
<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="NSF">National Science Foundation</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="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>
<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>
<date year="2008" />
<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 IANA procedures for registering port number
values for use with the various IETF transport protocols, including TCP,
UDP, DCCP, and SCTP. It provides clear procedures for the management of
the port number registry, which is important for its long-term
management. It updates RFC2780 by obsoleting Sections 8 and 9.1 of that
RFC, and it updates the IANA allocation procedures for DCCP as defined
in RFC4340.</t>
</abstract>
</front>
<middle>
<section anchor="intro" title="Introduction">
<t>The Transmission Control Protocol (TCP) <xref
target="RFC0793"></xref> and the User Datagram Protocol (UDP) <xref
target="RFC0768"></xref> have enjoyed a remarkable success over the
decades as the two most widely used transport protocols on the Internet.
They have introduced 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 also identify the
application protocol and associated service to which processes bind
<xref target="I-D.touch-tsvwg-port-guidelines"></xref>. Newer transport
protocols, such as the Stream Control Transmission Protocol (SCTP) <xref
target="RFC4960"></xref> and the Datagram Congestion Control Protocol
(DCCP) <xref target="RFC4342"></xref> have adopted the concept of ports
for their communication sessions and use port numbers in the same way as
TCP and 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" 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 can be a local decision between the endpoints of a
connection, most Internet components use a single, shared view of this
association, provided by the Internet Assigned Numbers Authority (IANA)
through the port number registry <xref target="REGISTRY"></xref>.</t>
<t>Designers of applications and application-level protocols may apply
to IANA for a registered port number for a specific application, and may
- after successful registration - assume that no other application will
use that port number for its communication sessions. It is important to
note that ownership of registered port numbers remains with IANA. For
many years, the allocation and registration of new port number values
for use with TCP and UDP have had less than clear guidelines.
Information about the registration procedures for the port namespace
existed in three locations: the forms for requesting port number
registrations on the IANA web site <xref target="SYSFORM"></xref><xref
target="USRFORM"></xref>, an introductory text section in the file
listing the port number registrations themselves <xref
target="REGISTRY"></xref>, and two brief sections of <xref
target="RFC2780"></xref>.</t>
<t>This document aggregates this scattered information into a single
reference and at the same time clarifies the guidelines for the
management of the port number space. It gives more detailed guidance to
prospective requesters of ports than the existing documentation, and it
streamlines the IANA procedures for the management of the port number
space, so that management requests can complete in a timely manner. A
key factor of this streamlining is to establish identical registration
procedures for transport protocol ports, independent of a specific
transport protocol. This document brings the IANA procedures for TCP and
UDP in line with those already in effect for SCTP and DCCP, resulting in
a single process that requesters and IANA follow for all port number
requests for all transport protocols, including those not yet
defined.</t>
<t>A second 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 space. TCP and UDP have been a remarkable success over
the last decades. Thousands of applications and application-level
protocols have registered ports 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 port number space follow
principles that ensure its long-term usefulness as a shared resource.
<xref target="principles"></xref> discusses these principles in detail.
Guidelines for users seeking port numbers, 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>
<t>In addition to detailing the IANA procedures for the initial
assignment of port numbers, 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 procedure by which IANA can
unilaterally revoke a prior port number registration. <xref
target="iana-procedures"></xref> discusses the specifics of these
procedures.</t>
<t><!--Unsure how to handle the following paragraph...O-->This document
also addresses two technical issues related to the ports registry that
are tangential to long-term stewardship. First, it clarifies that a
method for the early allocation of port numbers is available for IETF
working groups, in line with <xref target="RFC4020"></xref>. Second, it
discusses how the use of symbolic names for assigned ports (the
"keyword" field in <xref target="REGISTRY"></xref>) for Service Resource
Records (SRV RRs) in the Domain Name System (DNS) <xref
target="RFC2782"></xref> relates to the use of SRV RRs for applications
without an assigned port.</t>
<t>This document updates <xref target="RFC2780"></xref> by obsoleting
Sections 8 and 9.1 of that RFC. Note that <xref target="RFC5237"></xref>
updates a different subset of the IANA allocation guidelines originally
given in <xref target="RFC2780"></xref> (specifically, the policies on
the namespace of the IP protocol number and IPv6 next header).</t>
</section>
<section anchor="term" title="Terminology">
<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 BCP 14, RFC 2119 <xref
target="RFC2119"></xref>.</t>
</section>
<section anchor="types" title="Port Number Types">
<t>TCP, UDP, 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="requests"></xref> describes the IANA procedures for each range
in detail: <list style="symbols">
<t>the Well Known Ports, i.e., the System Ports, from 0-1023
(assigned by IANA)</t>
<t>the Registered Ports, i.e., the User Ports, from 1024-49151
(assigned by IANA)</t>
<t>the Dynamic Ports, i.e., 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="numbers">
<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>When this document was written, approximately 76% of the TCP and UDP
Well Known Ports were assigned, as were a significant fraction of the
Registered Ports. (As noted, Dynamic Ports are never assigned.)</t>
<section anchor="exp" title="Assigned Port Numbers for Experimentation">
<t>Of the Registered Ports, two TCP and UDP port numbers (1021 and
1022) have been assigned for experimentation with new applications and
application-layer protocols that require a port number in the
Registered Ports range <xref target="RFC4727"></xref>. <cref
anchor="sctp-dccp-exp" source="Lars">This document should register
ports 1021 and 1022 for DCCP and SCTP.</cref></t>
<t>The experimental ports 1021 and 1022 SHOULD be used for local
experiments only 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 Registered Ports range, and port numbers in the Dynamic
Ports range can be also used.</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 Space Management">
<t>Management procedures for the port number space include allocation of
port numbers upon request, as well as coordination of information about
existing allocations. The latter includes maintaining contact and
description information about assigned ports, revoking abandoned ports,
and redefining port allocations when needed. Of these procedures, port
number allocation is most critical, because of the limited number of
remaining port numbers.</t>
<t>Before the publication of this document, the principles of port
number space allocation followed some simple, undocumented
guidelines:</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 need to be unique</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 spaces were managed
separately from the TCP/UDP spaces</t>
</list>This document attempts to update these guidelines to more
conservatively manage the limited remaining TCP and UDP port number
spaces, recognizes the potential use of service names in the absence of
corresponding port number allocations, such as in SCTP and DCCP.</t>
<!--Verify that both SCTP and DCCP use service names without assigned port numbers.-->
<t>The basic principle of port number registry management is to conserve
the 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.</t>
<t>Port numbers are intended to indicate 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"></xref>. 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.</t>
<section title="Basic Principles of Port Conservation">
<t>This section summarizes the basic principles by which IANA attempts
to conserve the port number space. This description is intended to
inform applicants requesting 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>Conservation of the port number space recognizes that because this
space is a limited resource, applications are expected to participate
in the demultiplexing process where feasible. The port numbers are
expected to encode as little information as possible that will enable
an application to perform further demultiplexing by itself. In
particular, there should be:</t>
<t><list style="symbols">
<t>only one port per service</t>
<t>one port for all versions of a service</t>
<t>the same port for different types of devices using the same
service</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, 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"></xref>).</t>
<t>These principles of port conservation are explained in <xref
target="I-D.touch-tsvwg-port-guidelines"></xref>. That document
explains in further detail how ports are used in various ways,
notably:</t>
<t><list style="symbols">
<t>Endpoint process identifier</t>
<t>Application protocol identifier</t>
<t>Firewall filtering</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 de-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 of
a connection (again, as discussed in detail in <xref
target="I-D.touch-tsvwg-port-guidelines"></xref>).</t>
</section>
<section title="Principles Specific to Individual Port Number Ranges">
<t>It is important to note that different IANA procedures apply to
different ranges of the port number registry. <xref
target="requests"></xref> discusses the details of these procedures;
this section outlines the rationale for these differences:<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, and have a technical expert review this documentation to
determine whether to grant the registration request. This
documentation MUST explain why 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 one, the bar
for new allocations is higher than that for the Registered Ports
range (1024-49551). A request for a Well Known port number MUST
document why a port number in the Registered Ports or Dynamic
Ports ranges is unsuitable.</t>
</list></t>
</section>
<section title="New Principles">
<t>Several new practices stem from the conservation principle that
guides management of the port numbers registry, and will take effect
with the approval of this document:</t>
<t><list style="symbols">
<t>IANA will allocate port numbers only to the transport protocols
requested</t>
<t>IANA will recover unused port numbers, via the new procedures
of de-registration, revocation, and transfer</t>
</list></t>
<t>IANA will begin assigning protocol numbers only for 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 only for
one of these transport protocols. The new allocation procedure
conserves resources by only allocating a port number to an application
for 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, they 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 another registration with IANA. The
reason for this procedure is to allow allocation of reserved port
numbers on the day the range has no more unassigend values. <cref
source="Magnus" anchor="port-reserv">The usage of for the above reason reserved port
numbers should probably not have the same rules as the other reserved
ports. Needs discussion if we should separate this properly. I think
the IETF consultation part will make it difficult the day one registry
runs out of unassigned ones.</cref> </t>
<t>Conservation for the port numbers registry 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"></xref> describes these procedures, which so
far were undocumented.</t>
</section>
</section>
<section anchor="iana-procedures"
title="IANA Procedures for Managing the Port Number Space">
<t>IANA supports various procedures to manage the port number space that
enable ports to be registered, de-registered, reused, and revoked. This
section explains these procedures, as well as other related issues.</t>
<section anchor="registration" title="Port Number Registration">
<t>Registration refers to the allocation of port numbers to
applicants. All such registrations are made from port numbers that are
Unassigned or Reserved at the tine of the allocation. Unassigned
numbers are allocated as needed, and without further explanation.
Reserved numbers are assigned only after review by IANA and the IETF,
and are accompanied by a statement explaining the reason a reserved
number is appropriate for this action.</t>
<t>When a registration for one or more (but not all) transport
protocols is approved, the port number for the non-requested transport
protocol(s) will remain unassigned but is marked as reserved. However,
IANA SHOULD NOT assign that port number to any other application or
service until no port numbers remain unassigned in the request range.
The current registration owner of a port number MAY register the same
port number for other transport protocols when needed.</t>
<t>A port number registration consists of the following tuple:</t>
<t><list style="hanging">
<t hangText="Registration Contact:">Name and email address of the
contact person for the registration. This is REQUIRED. Additional
address information MAY be provided. For registrations done
through IETF-published RFCs, one or more technical contact persons
SHALL be provided. In addition, in this case the registration
ownership will belong to the IETF and not the technical contact
persons.</t>
<t hangText="Transport Protocol:">The transport protocol(s) for
which the port allocation is requested, currently limited to one
or more of TCP, UDP, SCTP, and DCCP</t>
<t hangText="Port Number:">The currently unassigned port number(s)
the requester suggests for allocation. If specified and when
possible, IANA is encouraged to allocate the suggested number. If
not specified, IANA will choose a suitable number from the
Registered Ports range.</t>
<t hangText="Broadcast, Multicast or Anycast:">Indicates whether
the protocol supports either broadcast, multicast or anycast
network layer addresses.</t>
<t hangText="Port Name:">The long name (description) of the port.
It should avoid all but the most well known acronyms.</t>
<t hangText="Service Name:">This short name for the port number,
used in various service selection and discovery mechanisms,
currently including TCPMUX <xref target="RFC1078"></xref> and DNS
SRV resource records <xref target="RFC2782"></xref>. This name is
limited to 14 bytes, case-insensitive US-ASCII letters, digits,
and dashes. It MUST NOT conflict with already allocated names in
the service name registry <cref anchor="serv-nam-reg"
source="Lars">Add citation to the service name registry draft,
when it exists</cref>.</t>
<t hangText="Reference:">A reference document describing the
protocol or application using this port. For registration requests
for Registered Ports, this documentation MUST explain why a port
number in the Dynamic Ports range is unsuitable for the given
application. For registration requests for Well Known Ports, this
documentation MUST explain why a port number in the Registered
Ports or Dynamic Ports ranges is unsuitable.</t>
</list>The following rules apply to the port number registry
database maintained by IANA: <cref anchor="database-rules"
source="Lars">Some of these rules below allow entries that aren't in
full alignment with the procedures in this document. I assume that is,
because the rules attempt to describe the state of the IANA database
including all existing entries? If so, we should make that
clearer.</cref></t>
<t><list style="symbols">
<t>Service Names MUST be unique</t>
<t>Service Name MUST exist for all transport protocols</t>
<t>Port Number MUST exist for TCP and UDP; it MAY exist for SCTP
and DCCP</t>
<t>Transport Protocol MUST exist for all entries</t>
<t>Service Code MUST NOT occur for TCP, UDP or SCTP, and MUST
occur for DCCP</t>
<t>Port Name MUST exist for all entries</t>
<t>Currently valid Registration Contact SHOULD exist for all
entries; it MUST exist for all new entries</t>
<t>Reference SHOULD exist for all entries</t>
</list></t>
</section>
<section anchor="deregistration" title="Port Number De-Registration">
<t>The original requesters 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 <cref anchor="res-vs-unass" source="Lars">This used to say
"unassigned" instead of "reserved". I suggest "reserved", so that IANA
has an indication in their list that they need to be careful when
re-assigning a previously de-registered port.</cref> 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 de-registration, IANA needs to confirm
that the port number is actually no longer in use.</t>
</section>
<section anchor="reuse" title="Port Number Re-Use">
<t>If the original requesters 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 followed by an immediate re-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>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 Revocation">
<t>Sometimes, it will be clear that a specific port number is no
longer in use and that IANA can de-register it and mark it as reserved
<cref anchor="res-vs-unass2" source="Lars">See [res-vs-unass].</cref>
But at other times, it may be unclear whether a given assigned port
number is still in use somewhere in the Internet. In those cases,
despite the requester's wish to de-register, IANA must consider the
consequences that de-registering the port number.</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>
</section>
<section anchor="transfer" title="Port Number Transfer">
<t>The value of port numbers is defined by their careful management as
a shared Internet resource, whereas enabling transfer allows the
potential for associated monetary exchanges to motivate this
management. As a result, current IANA procedures do not permit port
number assignments to be transferred between parties, even when they
are mutually consenting. The appropriate alternate procedure is for
the new party to request its own port number registration and for the
previous party to release its registration via the de-registration
procedure outlined above.</t>
</section>
<section title="Maintenance Issues">
<t>The previous procedures help IANA manage defining properties of the
port name space. There are additional procedures which are
administrative, and help IANA maintain non-defining information in a
registration. This includes changes to the Port Name (i.e.,
description), and changes to contact information. These changes are
coordinated by IANA in an informal manner, and may be initiated by
either the registrant or by IANA, e.g., the latter when requesting an
update to current contact information.</t>
</section>
</section>
<section anchor="requests" title="Port Number Space Requests">
<t>This section describes the process for requests associated with
IANA's management of the the port number space. Such requests include
initial registration, de-registration, re-use, changes to the service
name, as well as updates to the contact information or port name
(description). Revocation is initiated by IANA.</t>
<!--Does this include changes to the service name? that seems semantic, and should require the form, IMO (as noted above).-->
<section title="Request Procedure">
<t>All registration requests for a TCP, SCTP, DCCP and/or UDP ports
must contain the following pieces of information:</t>
<t><list style="hanging">
<t hangText="Port number tuple:">A port number tuple, as described
in <xref target="registration"></xref>. The port number would
typically be omitted; when provided, it indicates a preference for
requesting a currently unassigned value.</t>
<t hangText="Port Range:">Indicates the port range desired (i.e.,
Well Known Ports or Registered Ports).</t>
<t hangText="Requested Action:">One of REGISTER, DEREGISTER,
REUSE, SVC_NAME_CHANGE, or UPDATE_INFO (port name, registration
contact).</t>
<!--What characters are allowed in service names?-->
</list><!--Are service names supposed to be unique? does this document define that requirement?--></t>
<t>The Well Known Ports are assigned by IANA and cover the range
0-1023. On many systems, they can only be used by system (or root)
processes or by programs executed by privileged users. Registration
requests for a Well Known port number MUST follow the "IETF Review"
policy of <xref target="RFC5226"></xref>. Registrations for a port
number in this range MUST document why a port number in the Registered
Ports range will not fulfill the application needs.</t>
<t><!--[JT - IMO, this is an outdated artifact; since some systems allow all users to attach listening processes to these ports, clients cannot assume that such ports are run by privileged process. The only difference remaining is IETF review vs. expert review. Why do we care?]-->The
Registered Ports are assigned by IANA and on most systems can be used
by ordinary user processes or programs executed by ordinary users. The
Registered Ports are in the range 1024-49151. Registration requests
for a Registered Port number MUST follow the "Expert Review" policy of
<xref target="RFC5226"></xref>.</t>
</section>
</section>
<section anchor="seccons" title="Security Considerations">
<t>The IANA guidelines described in this document do not change the
security properties of either TCP, SCTP, DCCP or UDP.</t>
<t><!-- disclaimer from http://www.iana.org/assignments/port-numbers -->Assignment
of a port number does not in any way imply an endorsement of an
application or product, and the fact that network traffic is flowing to
or from a registered port number does not mean that it is "good"
traffic, or even that the 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 registered or not.</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 <xref
target="RFC2780"></xref>. Upon approval of this document, IANA is
requested to adopt the procedures described herein.</t>
<t>IANA should take immediate actions to resolve inconsistencies raised
by requirements of this document.<!--, notably [UNIQUE KEYS].--></t>
<t><!--[IS well-known deprecated?]--></t>
</section>
<section anchor="ack" title="Acknowledgments">
<t>The text in <xref target="dccp"></xref> is based on a suggestion by
Tom Phelan.</t>
<t>Lars Eggert is partly funded by <xref target="TRILOGY"></xref>, a
research project supported by the European Commission under its Seventh
Framework Program.</t>
</section>
</middle>
<!-- REFERENCE TEMPLATE
<reference anchor="reference.XXX">
<front>
<title>XXX</title>
<author initials="X." surname="XXX" fullname="XXX">
<organization abbrev="XXX">XXX</organization>
<address>
<postal>
<street>XXX</street>
<city>XXX</city>
<region>XXX</region>
<code>XXX</code>
<country>XXX</country>
</postal>
<phone>XXX</phone>
<facsimile>XXX</facsimile>
<email>XXX</email>
<uri>XXX</uri>
</address>
</author>
<date month="XXX" year="XXX"/>
</front>
<seriesInfo name="XXX" value="XXX"/>
<format type="XXX" target="XXX"/>
</reference>
-->
<back>
<references title="Normative References">
<?rfc include="reference.RFC.0768" ?>
<?rfc include="reference.RFC.0793" ?>
<?rfc include="reference.RFC.2119" ?>
<?rfc include="reference.RFC.2780" ?>
<?rfc include="reference.RFC.4020" ?>
<?rfc include="reference.RFC.4340" ?>
<?rfc include="reference.RFC.4727" ?>
<?rfc include="reference.RFC.5226" ?>
</references>
<references title="Informative References">
<?rfc include="reference.RFC.0959" ?>
<?rfc include="reference.RFC.1078" ?>
<?rfc include="reference.RFC.2782" ?>
<?rfc include="reference.RFC.4342" ?>
<?rfc include="reference.RFC.4960" ?>
<?rfc include="reference.RFC.5237" ?>
<reference anchor="I-D.touch-tsvwg-port-guidelines">
<front>
<title>Guidelines for Transport Port Use</title>
<author fullname="Joe Touch" initials="J" surname="Touch">
<organization></organization>
</author>
<date month="July" year="2008" />
</front>
<seriesInfo name="" value="Work in Progress" />
</reference>
<reference anchor="SYSFORM">
<front>
<title>Application for System (Well Known) Port Number</title>
<author surname="Internet Assigned Numbers Authority (IANA)">
<organization />
</author>
</front>
<seriesInfo name=""
value="http://www.iana.org/cgi-bin/sys-port-number.pl" />
</reference>
<reference anchor="USRFORM">
<front>
<title>Application for User (Registered) Port Number</title>
<author surname="Internet Assigned Numbers Authority (IANA)">
<organization />
</author>
</front>
<seriesInfo name=""
value="http://www.iana.org/cgi-bin/usr-port-number.pl" />
</reference>
<reference anchor="REGISTRY">
<front>
<title>Port Numbers</title>
<author surname="Internet Assigned Numbers Authority (IANA)">
<organization />
</author>
</front>
<seriesInfo name=""
value="http://www.iana.org/assignments/port-numbers" />
</reference>
<reference anchor="TRILOGY">
<front>
<title>Trilogy Project</title>
<author>
<organization />
</author>
</front>
<seriesInfo name="" value="http://www.trilogy-project.org/" />
</reference>
</references>
<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 as defined in <xref
target="RFC4340"></xref>.</t>
<section title="DCCP Service Code Registry">
<t>Service Codes are allocated first-come-first-served according to
Section 19.8 of <xref target="RFC4340"></xref>. This document updates
Section 19.8 of <xref target="RFC4340"></xref> 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 when a
request seeks an appreciable number of Service Codes (e.g., more
than five).</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"></xref>.</t>
</list></t>
</section>
<section title="DCCP Port Numbers Registry">
<t>The DCCP ports registry is defined by <xref
target="RFC4340"></xref> in Section 19.9. Allocations in this registry
require prior allocation of a Service Code. Not all Service Codes
require IANA-registered ports. This document updates Section 19.9 of
<xref target="RFC4340"></xref> 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
IETF Action prior to allocation by IANA <xref
target="RFC4340"></xref>.</t>
</list></t>
<t>Section 19.9 of <xref target="RFC4340"></xref> requires each DCCP
server port assignment to be associated with at least one Service Code
value. This document updates <xref target="RFC4340"></xref> in the
following way:</t>
<t><list style="symbols">
<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><xref target="RFC4340"></xref> 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>
</back>
</rfc>| PAFTECH AB 2003-2026 | 2026-04-23 22:43:05 |