draft-ietf-tsvwg-iana-ports-01.txt   draft-ietf-tsvwg-iana-ports-02.txt 
Transport Area Working Group M. Cotton Transport Area Working Group M. Cotton
Internet Draft ICANN Internet-Draft ICANN
Updates: 2780, 4340 (if approved) L. Eggert Updates: 2780, 4340 L. Eggert
Intended status: BCP Nokia (if approved) Nokia
Expires: May 2009 A. Mankin Intended status: BCP A. Mankin
Johns Hopkins Univ. Expires: February 12, 2010 Johns Hopkins Univ.
M. Westerlund
Ericsson
J. Touch J. Touch
USC/ISI USC/ISI
November 3, 2008 M. Westerlund
Ericsson
August 11, 2009
IANA Procedures for the Transport Protocol Port Number Space Internet Assigned Numbers Authority (IANA) Procedures for the Management
draft-ietf-tsvwg-iana-ports-01.txt of the Transport Protocol Port Number and Service Name Registry
draft-ietf-tsvwg-iana-ports-02
Status of this Memo Status of this Memo
By submitting this Internet-Draft, each author represents that This Internet-Draft is submitted to IETF in full conformance with the
any applicable patent or other IPR claims of which he or she is provisions of BCP 78 and BCP 79. This document may contain material
aware have been or will be disclosed, and any of which he or she from IETF Documents or IETF Contributions published or made publicly
becomes aware will be disclosed, in accordance with Section 6 of available before November 10, 2008. The person(s) controlling the
BCP 79. copyright in some of this material may not have granted the IETF
Trust the right to allow modifications of such material outside the
IETF Standards Process. Without obtaining an adequate license from
the person(s) controlling the copyright in such materials, this
document may not be modified outside the IETF Standards Process, and
derivative works of it may not be created outside the IETF Standards
Process, except to format it for publication as an RFC or to
translate it into languages other than English.
Internet-Drafts are working documents of the Internet Engineering Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF), its areas, and its working groups. Note that Task Force (IETF), its areas, and its working groups. Note that
other groups may also distribute working documents as Internet- other groups may also distribute working documents as Internet-
Drafts. Drafts.
Internet-Drafts are draft documents valid for a maximum of six months Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress." material or to cite them other than as "work in progress."
The list of current Internet-Drafts can be accessed at The list of current Internet-Drafts can be accessed at
http://www.ietf.org/ietf/1id-abstracts.txt http://www.ietf.org/ietf/1id-abstracts.txt.
The list of Internet-Draft Shadow Directories can be accessed at The list of Internet-Draft Shadow Directories can be accessed at
http://www.ietf.org/shadow.html http://www.ietf.org/shadow.html.
This Internet-Draft will expire on May 3, 2009. This Internet-Draft will expire on February 12, 2010.
Copyright Notice
Copyright (c) 2009 IETF Trust and the persons identified as the
document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents in effect on the date of
publication of this document (http://trustee.ietf.org/license-info).
Please review these documents carefully, as they describe your rights
and restrictions with respect to this document.
Abstract Abstract
This document defines the IANA procedures for registering port number This document defines the procedures that the Internet Assigned
values for use with the various IETF transport protocols, including Numbers Authority (IANA) uses when handling registration and other
TCP, UDP, DCCP, and SCTP. It provides clear procedures for the requests related to the transport protocol port number and service
management of the port number registry, which is important for its name registry. It also discusses the rationale and principles behind
long-term management. It updates RFC2780 by obsoleting Sections 8 these procedures and how they facilitate the long-term sustainability
and 9.1 of that RFC, and it updates the IANA allocation procedures of the registry.
for DCCP as defined in RFC4340.
This document 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.
Table of Contents Table of Contents
1. Introduction...................................................2 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 4
2. Conventions used in this document..............................4 2. Conventions Used in this Document . . . . . . . . . . . . . . 5
3. Port Number Types..............................................5 3. Motivation . . . . . . . . . . . . . . . . . . . . . . . . . . 5
3.1. Assigned Port Numbers for Experimentation.................5 4. Port Number Ranges . . . . . . . . . . . . . . . . . . . . . . 6
4. Principles for Port Number Space Management....................6 4.1. Port Numbers and Service Names for Experimentation . . . . 7
4.1. Basic Principles of Port Conservation.....................7 5. Principles for Port Number and Service Name Registry
4.2. Principles Specific to Individual Port Number Ranges......8 Management . . . . . . . . . . . . . . . . . . . . . . . . . . 8
4.3. New Principles............................................9 5.1. Basic Principles of Port Number Conservation . . . . . . . 9
5. IANA Procedures for Managing the Port Number Space............10 5.2. Variances for Specific Port Number Ranges . . . . . . . . 10
5.1. Port Number Registration.................................10 5.3. New Principles . . . . . . . . . . . . . . . . . . . . . . 11
5.2. Port Number De-Registration..............................12 6. IANA Procedures for Managing the Port Number and Service
5.3. Port Number Re-Use.......................................12 Name Registry . . . . . . . . . . . . . . . . . . . . . . . . 12
5.4. Port Number Revocation...................................12 6.1. Port Number or Service Name Registration . . . . . . . . . 12
5.5. Port Number Transfer.....................................13 6.2. Port Number and Service Name De-Registration . . . . . . . 14
5.6. Maintenance Issues.......................................13 6.3. Port Number and Service Name Re-Use . . . . . . . . . . . 14
6. Port Number Space Requests....................................13 6.4. Port Number and Service Name Revocation . . . . . . . . . 15
6.1. Request Procedure........................................13 6.5. Port Number and Service Name Transfers . . . . . . . . . . 15
7. Security Considerations.......................................14 6.6. Maintenance Issues . . . . . . . . . . . . . . . . . . . . 16
8. IANA Considerations...........................................14 7. Security Considerations . . . . . . . . . . . . . . . . . . . 16
9. Acknowledgments...............................................15 8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 16
10. References...................................................16 8.1. Service Name Consistency . . . . . . . . . . . . . . . . . 17
10.1. Normative References....................................16 8.2. Port Numbers for SCTP and DCCP Experimentation . . . . . . 18
10.2. Informative References..................................16 8.3. Updates to DCCP Registries . . . . . . . . . . . . . . . . 19
APPENDIX A: Updates to DCCP Registries...........................19 9. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 20
A.1. DCCP Service Code Registry...............................19 10. References . . . . . . . . . . . . . . . . . . . . . . . . . . 21
A.1. DCCP Port Numbers Registry.....Error! Bookmark not defined. 10.1. Normative References . . . . . . . . . . . . . . . . . . . 21
10.2. Informative References . . . . . . . . . . . . . . . . . . 21
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 23
1. Introduction 1. Introduction
The Transmission Control Protocol (TCP) [RFC0793] and the User The Transmission Control Protocol (TCP) [RFC0793] and the User
Datagram Protocol (UDP) [RFC0768] have enjoyed a remarkable success Datagram Protocol (UDP) [RFC0768] have enjoyed a remarkable success
over the decades as the two most widely used transport protocols on over the decades as the two most widely used transport protocols on
the Internet. They have introduced the concept of "ports" as logical the Internet. They have introduced the concept of "ports" as logical
entities for Internet communication. Ports serve two purposes: entities for Internet communication. Ports serve two purposes:
first, they provide a demultiplexing identifier to differentiate first, they provide a demultiplexing identifier to differentiate
transport sessions between the same pair of endpoints, and second, transport sessions between the same pair of endpoints, and second,
they also identify the application protocol and associated service to they also identify the application protocol and associated service to
which processes bind [I-D.touch-tsvwg-port-guidelines]. Newer which processes bind. Newer transport protocols, such as the Stream
transport protocols, such as the Stream Control Transmission Protocol Control Transmission Protocol (SCTP) [RFC4960] and the Datagram
(SCTP) [RFC4960] and the Datagram Congestion Control Protocol (DCCP) Congestion Control Protocol (DCCP) [RFC4342] have adopted the concept
[RFC4342] have adopted the concept of ports for their communication of ports for their communication sessions and use port numbers in the
sessions and use port numbers in the same way as TCP and UDP. same way as TCP and UDP. UDP-Lite [RFC3828], a variant of UDP, is
also making use of UDP port numbers. For the purposes of this
document, all rules stated for UDP also apply to UDP-Lite, because it
uses the same assignments as UDP.
Port numbers are the original and most widely used means for Port numbers are the original and most widely used means for
application and service identification on the Internet. Ports are application and service identification on the Internet. Ports are
16-bit numbers, and the combination of source and destination port 16-bit numbers, and the combination of source and destination port
numbers together with the IP addresses of the communicating end numbers together with the IP addresses of the communicating end
systems uniquely identifies a session of a given transport protocol. systems uniquely identifies a session of a given transport protocol.
Port numbers are also known by their corresponding service names such Port numbers are also known by their corresponding service names such
as "telnet" for port number 23 and "http" for port number 80. as "telnet" for port number 23 and both "http" and "www" for port
number 80.
Hosts running services, hosts accessing services on other hosts, and Hosts running services, hosts accessing services on other hosts, and
intermediate devices (such as firewalls and NATs) that restrict intermediate devices (such as firewalls and NATs) that restrict
services need to agree on which service corresponds to a particular services need to agree on which service corresponds to a particular
destination port. Although this can be a local decision between the destination port. Although this can be a local decision between the
endpoints of a connection, most Internet components use a single, endpoints of a connection, most Internet components use a single,
shared view of this association, provided by the Internet Assigned shared view of this association, provided by the Internet Assigned
Numbers Authority (IANA) through the port number registry [REGISTRY]. Numbers Authority (IANA) through the port number registry [REGISTRY].
Designers of applications and application-level protocols may apply Applications either use numeric port numbers directly, look up port
to IANA for a registered port number for a specific application, and numbers based on service names via system calls such as
may - after successful registration - assume that no other getservbyname() on UNIX, or - more recently - use service names to
application will use that service port number for its communication look up a service resource records (SRV RRs) [RFC2782] via the Domain
sessions. It is important to note that ownership of registered port Name System (DNS) [RFC1034] in a variety of ways [RFC1078]
numbers remains with IANA. For many years, the allocation and [I-D.cheshire-dnsext-dns-sd][I-D.cheshire-dnsext-multicastdns] to
registration of new port number values for use with TCP and UDP have obtain the port number of a given service.
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
[SYSFORM][USRFORM], an introductory text section in the file listing
the port number registrations themselves [REGISTRY], and two brief
sections of [RFC2780].
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.
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. Section 4 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 companion document [I-D.touch-tsvwg-port-guidelines].
In addition to detailing the IANA procedures for the initial Designers of applications and application-level protocols may apply
assignment of port numbers, this document also specifies post- to IANA for an assigned port number and service name for a specific
assignment procedures that until now have been handled in an ad hoc application, and may - after successful registration - assume that no
manner. These include procedures to de-register a port number that other application will use that port number and service name for its
is no longer in use, to re-use a port number allocated for one communication sessions. Alternatively, application designers may
application that is no longer in use for another application, and also only ask for an assigned service name, if their application does
procedure by which IANA can unilaterally revoke a prior port number not require a port number. The latter alternative is encouraged when
registration. Section 5 discusses the specifics of these procedures. possible, in order to conserve the more limited port number space.
It is important to note that ownership of registered port numbers and
service names remains with IANA.
This document also addresses two technical issues related to the For protocols developed by IETF working groups, IANA offers a method
ports registry that are tangential to long-term stewardship. First, for the "early" assignment of port numbers and service names, in line
it clarifies that a method for the early allocation of port numbers with [RFC4020], as described in Section 6.1.
is available for IETF working groups, in line with [RFC4020].
Second, it discusses how the use of symbolic names for assigned ports
(the "keyword" field in [REGISTRY]) for Service Resource Records (SRV
RRs) in the Domain Name System (DNS) [RFC2782] relates to the use of
SRV RRs for applications without an assigned port.
This document updates [RFC2780] by obsoleting Sections 8 and 9.1 of This document updates [RFC2780] by obsoleting Sections 8 and 9.1 of
RFC. Note that [RFC5237] updates a different subset of the IANA that RFC. Note that [RFC5237] updates a different subset of the IANA
allocation guidelines originally given in [RFC2780] (specifically, allocation guidelines originally given in [RFC2780] (specifically,
the policies on the namespace of the IP protocol number and IPv6 next the policies on the namespace of the IP protocol number and IPv6 next
header). header).
2. Conventions used in this document 2. Conventions Used in this Document
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in RFC-2119 [RFC2119]. document are to be interpreted as described in BCP 14, RFC 2119
[RFC2119].
3. Port Number Types 3. Motivation
For many years, the allocation and registration of new port number
values and service names for use with TCP and UDP have had less than
clear guidelines. Information about the registration procedures for
the port registry existed in three locations: the forms for
requesting port number registrations on the IANA web site [SYSFORM]
[USRFORM], an introductory text section in the file listing the port
number registrations themselves [REGISTRY], and two brief sections of
[RFC2780].
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 [SYSFORM]
[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 became popular, the
ambiguities in the syntactic definition of the service namespace,
together with a 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 [SRVTYPE].
This document aggregates 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. It also merges the service name
registrations that have occurred in the ad-hoc [SRVTYPE] registry
into the IANA registry [REGISTRY], because under the new IANA
guidelines, registering service names without port numbers has become
possible.
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 already in effect 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.
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 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. Section 5 discusses these
principles in detail.
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 procedure by which IANA can unilaterally revoke a prior port
number registration. Section 6 discusses the specifics of these
procedures.
4. Port Number Ranges
TCP, UDP (and UDP-Lite), SCTP and DCCP use 16-bit namespaces for TCP, UDP (and UDP-Lite), SCTP and DCCP use 16-bit namespaces for
their port number registries. The port registries for all these their port number registries. The port registries for all these
transport protocols are subdivided into three ranges of numbers, and transport protocols are subdivided into three ranges of numbers, and
Section 6 describes the IANA procedures for each range in detail: Section 5.2 describes the IANA procedures for each range in detail:
o the Well Known Ports, i.e., the System Ports, from 0-1023 o the Well Known Ports, also known as the System Ports, from 0-1023
(assigned by IANA) (assigned by IANA)
o the Registered Ports, i.e., the User Ports, from 1024-49151 o the Registered Ports, also known as the User Ports, from 1024-
(assigned by IANA) 49151 (assigned by IANA)
o the Dynamic Ports, i.e., the Private Ports, from 49152-65535 o the Dynamic Ports, also known as the Private Ports, from 49152-
(never assigned) 65535 (never assigned)
Of the assignable port ranges (Well Known and Registered, i.e., port Of the assignable port ranges (Well Known and Registered, i.e., port
numbers 0-49151), individual port numbers are in one of three states numbers 0-49151), individual port numbers are in one of three states
at any given time: at any given time:
1. Assigned: Assigned port numbers are currently allocated to the o Assigned: Assigned port numbers are currently allocated to the
service indicated in the registry. service indicated in the registry.
2. Unassigned: Unassigned port numbers are currently available for o Unassigned: Unassigned port numbers are currently available for
assignment upon request, as per the procedures outlined in this assignment upon request, as per the procedures outlined in this
document. document.
3. Reserved: Reserved port numbers are not available for regular o Reserved: Reserved port numbers are not available for regular
assignment; they are "assigned to IANA" for special purposes. assignment; they are "assigned to IANA" for special purposes.
Reserved port numbers include values at the edges of each range, Reserved port numbers include values at the edges of each range,
e.g., 0, 1023, 1024, etc., which may be used to extend these e.g., 0, 1023, 1024, etc., which may be used to extend these
ranges or the overall port number space in the future. ranges or the overall port number space in the future.
When this document was written, approximately 76% of the TCP and UDP In order to keep the size of the registry manageable, IANA typically
Well Known Ports were assigned, as were a significant fraction of the only records the Assigned and Reserved port numbers and service names
Registered Ports. (As noted, Dynamic Ports are never assigned.) in the registry. Unassigned values are typically not explicitly
listed.
3.1. Assigned Port Numbers for Experimentation As a data point, 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.)
Of the Well-Known Ports, two TCP and UDP port numbers (1021 and 1022) 4.1. Port Numbers and Service Names for Experimentation
have been assigned for experimentation with new applications and
application-layer protocols that require a port number in the
assigned ports ranges [RFC4727]. [sctp-dccp-exp]
The experimental ports 1021 and 1022 SHOULD be used for local Of the Well Known ports, two TCP and UDP port numbers (1021 and
experiments only in controlled environments, and they SHOULD NOT be 1022), together with their respective service names ("exp1" and
used on the global Internet. Many new applications and application- "exp2"), have been assigned for experimentation with new applications
layer protocols can be experimented with without requiring a port in and application-layer protocols that require a port number in the
the Well-Known or Registered Ports range, and port numbers in the assigned ports ranges [RFC4727]. This document registers the same
Dynamic Ports range can be also used. two port numbers and service names for experimentation with new
application-layer protocols over SCTP and DCCP in Section 8.2.
Please refer to Sections 1 and 1.1 of [RFC3692] for how these
experimental port numbers are to be used. 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,
and port numbers in the Dynamic Ports range can be also used.
Unfortunately, it can be difficult to limit access to these ports. Unfortunately, it can be difficult to limit access to these ports.
Users SHOULD take measures to ensure that experimental ports are Users SHOULD take measures to ensure that experimental ports are
connecting to the intended process. For example, users of these connecting to the intended process. For example, users of these
experimental ports might include a 64-bit nonce, once on each segment experimental ports might include a 64-bit nonce, once on each segment
of a message-oriented channel (e.g., UDP), or once at the beginning of a message-oriented channel (e.g., UDP), or once at the beginning
of a byte-stream (e.g., TCP), which is used to confirm that the port of a byte-stream (e.g., TCP), which is used to confirm that the port
is being used as intended. Such confirmation of intended use is is being used as intended. Such confirmation of intended use is
especially important when these ports are associated with privileged especially important when these ports are associated with privileged
(e.g., system or administrator) processes. (e.g., system or administrator) processes.
4. Principles for Port Number Space Management 5. Principles for Port Number and Service Name Registry Management
Management procedures for the port number space include allocation of Management procedures for the port number and service name registry
port numbers upon request, as well as coordination of information include allocation of port numbers and service names upon request, as
about existing allocations. The latter includes maintaining contact well as coordination of information about existing allocations. The
and description information about assigned ports, revoking abandoned latter includes maintaining contact and description information about
ports, and redefining port allocations when needed. Of these assignments, revoking abandoned assignments, and redefining
procedures, port number allocation is most critical, because of the assignments when needed. Of these procedures, port number allocation
limited number of remaining port numbers. is most critical, because of the limited number of remaining port
numbers. The namespace available for service names is much larger,
which allows for simpler management procedures.
Before the publication of this document, the principles of port Before the publication of this document, the principles of port
number space allocation followed some simple, undocumented number and service name management followed some simple, mostly
guidelines: undocumented guidelines:
o TCP and UDP ports were simultaneously allocated when either was o TCP and UDP ports were simultaneously allocated when either was
requested requested
o Port numbers were the primary allocation; service names were o Port numbers were the primary allocation; service names were
informative only, and did not need to be unique informative only, and did not have a well-defined syntax
o Port numbers were conserved informally, and sometimes o Port numbers were conserved informally, and sometimes
inconsistently (e.g., some services were allocated ranges of many inconsistently (e.g., some services were allocated ranges of many
port numbers even where not strictly necessary) port numbers even where not strictly necessary)
o SCTP and DCCP port number and service name spaces were managed o SCTP and DCCP port number and service name registries were managed
separately from the TCP/UDP spaces separately from the TCP/UDP registries
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.
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.
Port numbers are intended to indicate a service and enable process o Until recently, service names could not be assigned without
demultiplexing at an endpoint; uses beyond those basic requirements assigning a corresponding port number
should be avoided [I-D.touch-tsvwg-port-guidelines]. This document This document attempts to document, clarify and align these
also focuses on service names as a unique identifier, to increase the guidelines in order to more conservatively manage the limited
space available (from 4 bytes to 14), and to enable their use in the remaining port number space and to enable and promote the use of
absence of corresponding port number assignments. service names for service identification without associated port
numbers, where possible.
4.1. Basic Principles of Port Conservation 5.1. Basic Principles of Port Number Conservation
This section summarizes the basic principles by which IANA attempts This section summarizes the basic principles by which IANA attempts
to conserve the port number space. This description is intended to to conserve the port number space. This description is intended to
inform applicants requesting port numbers. IANA decisions are not inform applicants requesting port numbers. IANA decisions are not
required to be bound to these principles, however; other factors may required to be bound to these principles, however; other factors may
come into play, and exceptions may occur where deemed in the best come into play, and exceptions may occur where deemed in the best
interest of the Internet. interest of the Internet.
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.
Conservation of the port number space recognizes that because this Conservation of the port number space recognizes that because this
space is a limited resource, applications are expected to participate space is a limited resource, applications are expected to participate
in the demultiplexing process where feasible. The port numbers are in the traffic demultiplexing process where feasible. The port
expected to encode as little information as possible that will enable numbers are expected to encode as little information as possible that
an application to perform further multiplexing by itself. In will still enable an application to perform further demultiplexing by
particular, there should be: itself. In particular, there should be:
o only one port per service
o one port for all versions of a service o only one assigned port number per service or application
o the same port for different types of devices using the same o only one assigned port number for all versions of a service (e.g.,
running the service with or without a security mechanism)
service o only one assigned port number for all different types of devices
using or participating in the same service
A given service is expected to further demultiplex messages where A given service is expected to further demultiplex messages where
possible. For example, applications and protocols are expected to possible. For example, applications and protocols are expected to
include in-band version information, so that future versions of the include in-band version information, so that future versions of the
application or protocol can share the same allocated port. application or protocol can share the same allocated port.
Applications and protocols are also expected to be able to Applications and protocols are also expected to be able to
efficiently use a single allocated port, either by demultiplexing efficiently use a single allocated port for multiple sessions, either
multiple streams within one port, or using the allocated port to by demultiplexing multiple streams within one port, or using the
coordinate using dynamic ports for subsequent exchanges (e.g., in the allocated port to coordinate using dynamic ports for subsequent
spirit of FTP [RFC0959]). exchanges (e.g., in the spirit of FTP [RFC0959]).
These principles of port conservation are explained in [I-D.touch- Ports are used in various ways, notably:
tsvwg-port-guidelines]. That document explains in further detail how
ports are used in various ways, notably:
o Endpoint process identifier o as endpoint process identifiers
o Application protocol identifier o as application protocol identifiers
o Firewall filtering o for firewall filtering purposes
The process and protocol identifier use suggests that anything a The process and protocol identifier use suggests that anything a
single process can demultiplex, or that can be encoded into a single single process can demultiplex, or that can be encoded into a single
protocol, should be. The firewall filtering use suggests that some protocol, should be. The firewall filtering use suggests that some
uses that could be de-multiplexed or encoded must be separated to uses that could be de-multiplexed or encoded must be separated to
allow for firewall management. Note that this latter use is much allow for firewall management. Note that this latter use is much
less sound, because port numbers have meaning only for the two less sound, because port numbers have meaning only for the two
endpoints of a connection (again, as discussed in detail in [I- endpoints involved in a connection, and drawing conclusions about the
D.touch-tsvwg-port-guidelines]). service that generated a given flow based on observed port numbers is
inherently problematic.
4.2. Principles Specific to Individual Port Number Ranges 5.2. Variances for Specific Port Number Ranges
It is important to note that different IANA procedures apply to Section 4 describes the different port number ranges. It is
different ranges of the port number registry. Section 6 discusses important to note that IANA applies slightly different procedures
the details of these procedures; this section outlines the rationale when managing the different ranges of the port number registry:
for these differences:
o Ports in the Dynamic Ports range (49152-65535) have been o Ports in the Dynamic Ports range (49152-65535) have been
specifically set aside for local and dynamic use and cannot be specifically set aside for local and dynamic use and cannot be
registered through IANA. Applications may simply use them for registered through IANA. Applications may simply use them for
communication without any sort of registration. On the other communication without any sort of registration. On the other
hand, applications MUST NOT assume that a specific port number in hand, applications MUST NOT assume that a specific port number in
the Dynamic Ports range will always be available for communication the Dynamic Ports range will always be available for communication
at all times, and a port number in that range hence MUST NOT be at all times, and a port number in that range hence MUST NOT be
used as a service identifier. used as a service identifier.
o Ports in the Registered Ports range (1024-49151) are available for o Ports in the Registered Ports range (1024-49151) are available for
registration through IANA, and MAY be used as service identifiers registration through IANA, and MAY be used as service identifiers
upon successful registration. Because registering a port number upon successful registration. Because registering a port number
for a specific application consumes a fraction of the shared for a specific application consumes a fraction of the shared
resource that is the port number registry, IANA will require the resource that is the port number registry, IANA will require the
requester to document the intended use of the port number, and requester to document the intended use of the port number. This
have a technical expert review this documentation to determine documentation will be input to the "Expert Review" allocation
whether to grant the registration request. This documentation procedure [RFC5226], by which IANA will have a technical expert
MUST explain why a port number in the Dynamic Ports range is review the request to determine whether to grant the registration.
unsuitable for the given application. The submitted documentation MUST explain why using a port number
in the Dynamic Ports range is unsuitable for the given
application.
o Ports in the Well Known Ports range (0-1023) are also available o Ports in the Well Known Ports range (0-1023) are also available
for registration through IANA. Because the Well Known Ports range for registration through IANA. Because the Well Known Ports range
is both the smallest and the most densely allocated one, the bar is both the smallest and the most densely allocated one, the bar
for new allocations is higher than that for the Registered Ports for new allocations is higher than that for the Registered Ports
range (1024-49551). A request for a Well Known port number MUST range, and will only be granted under the "IETF Review" allocation
document why a port number in the Registered Ports or Dynamic procedure [RFC5226]. A request for a Well Known port number MUST
Ports ranges is unsuitable. document why using a port number from both the Registered Ports
and Dynamic Ports ranges is unsuitable for the given application.
4.3. New Principles 5.3. New Principles
Several new practices stem from the conservation principle that Several new practices stem from the conservation principle that
guides management of the port numbers registry, and will take effect guides management of the port number and service name registry, and
with the approval of this document: will take effect with the approval of this document:
o IANA will allocate port numbers only to the transport protocols o IANA will allocate port numbers only to the transport protocols
requested explicitly named in an allocation request
o IANA will recover unused port numbers, via the new procedures of o IANA will recover unused port numbers, via the new procedures of
de-registration, revocation, and transfer de-registration, revocation, and transfer
o IANA will begin assigning service names without requiring a
corresponding port number allocation
IANA will begin assigning protocol numbers only for those transport IANA will begin assigning protocol numbers only for those transport
protocols explicitly included in a registration request. This ends protocols explicitly included in a registration request. This ends
the long-standing practice of automatically assigning a port number the long-standing practice of automatically assigning a port number
to an application for both TCP and a UDP, even if the request is only 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 for one of these transport protocols. The new allocation procedure
conserves resources by only allocating a port number to an conserves resources by only allocating a port number to an
application for those transport protocols (TCP, UDP, SCTP and/or application for those transport protocols (TCP, UDP, SCTP and/or
DCCP) it actually uses. The port number will be marked as reserved - DCCP) it actually uses. The port number will be marked as Reserved -
instead of assigned - in the port number registries of the other instead of Assigned - in the port number registries of the other
transport protocols. When applications start supporting the use of transport protocols. When applications start supporting the use of
some of those additional transport protocols, they must request IANA some of those additional transport protocols, their implementors MUST
to convert the reservation into an assignment. An application MUST request IANA to convert the reservation into an assignment. An
NOT assume that it can use a port number assigned to it for use with application MUST NOT assume that it can use a port number assigned to
one transport protocol with another transport protocol without it for use with one transport protocol with another transport
another registration with IANA. The reason for this procedure is to protocol without asking IANA to convert the reservation into an
allow allocation of reserved port numbers on the day the range has no assignment.
more unassigend values. [port-reserv]
Conservation for the port numbers registry is improved by procedures Conservation of port numbers is improved by procedures that allow
that allow previously allocated port numbers to become unassigned, previously allocated port numbers to become Unassigned, either
either through de-registration or through revocation, and by a through de-registration or through revocation, and by a procedure
procedure that lets application designers transfer an allocated but that lets application designers transfer an allocated but unused port
unused port number to a new application. Section 5 describes these number to a new application. Section 6 describes these procedures,
procedures, which so far were undocumented. which so far were undocumented. Port number conservation is also
improved by recommending that applications that do not require an
allocated port, e.g., because they can use service-name-based
lookups, chose this option and only register a service name.
5. IANA Procedures for Managing the Port Number Space 6. IANA Procedures for Managing the Port Number and Service Name
Registry
IANA supports various procedures to manage the port number space that This section describes the process for requests associated with
enable ports to be registered, de-registered, reused, and revoked. IANA's management of the port number and service name registry. Such
This section explains these procedures, as well as other related requests include initial registration, de-registration, re-use,
issues. changes to the service name, as well as updates to the contact
information or description associated with an assignment. Revocation
is initiated by IANA.
5.1. Port Number Registration 6.1. Port Number or Service Name Registration
Registration refers to the allocation of port numbers to applicants. Registration refers to the allocation of port numbers or service
All such registrations are made from port numbers that are Unassigned names to applicants. All such, registrations are made from port
or Reserved at the time of the allocation. Unassigned numbers are numbers or service names that are Unassigned or Reserved at the time
allocated as needed, and without further explanation. Reserved of the allocation. Unassigned numbers and names are allocated as
numbers are assigned only after review by IANA and the IETF, and are needed, and without further explanation. Reserved numbers and names
accompanied by a statement explaining the reason a reserved number is are assigned only after review by IANA and the IETF, and are
appropriate for this action. accompanied by a statement explaining the reason a Reserved number or
name is appropriate for this action.
When a registration for one or more (but not all) transport protocols When a registration for one or more (but not all) transport protocols
is approved, the port number for the non-requested transport is approved, the port number for the non-requested transport
protocol(s) will remain unassigned but is marked as reserved. protocol(s) will be marked as Reserved. IANA SHOULD NOT assign that
However, IANA SHOULD NOT assign that port number to any other port number to any other application or service until no other port
application or service until no port numbers remain unassigned in the numbers remain Unassigned in the requested range. The current
request range. The current registration owner of a port number MAY registration owner of a port number MAY register these Reserved port
register the same port number for other transport protocols when numbers for other transport protocols when needed.
needed.
A port number registration consists of the following tuple: 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.
A port number or service name registration consists of the following
information:
o Registration Technical Contact: Name and email address of the o Registration Technical Contact: Name and email address of the
technical contact person for the registration. This is REQUIRED. technical contact person for the registration. This is REQUIRED.
Additional address information MAY be provided. For registrations Additional address information MAY be provided. For registrations
done through IETF-published RFCs, one or more technical contact done through IETF-published RFCs, one or more technical contact
persons SHALL be provided. persons SHALL be provided.
o Registration Owner: Name and email address of the owner of the o Registration Owner: Name and email address of the owner of the
registration. This is REQUIRED. For individuals, this is the same registration. This is REQUIRED. For individuals, this is the
as the registration technical contact; for organizations, this is same as the registration technical contact; for organizations,
a point of contact at that organization. For registrations done this is a point of contact at that organization. For
through IETF-published RFCs, the registration ownership will registrations done through IETF-published RFCs, the registration
belong to the IETF and not the technical contact persons. ownership will belong to the IETF and not the technical contact
persons.
o Transport Protocol: The transport protocol(s) for which the port o Transport Protocol: The transport protocol(s) for which the port
allocation is requested, currently limited to one or more of TCP, number or service name allocation is requested MUST be provided.
UDP, SCTP, and DCCP. This field is currently limited to one or more of TCP, UDP, SCTP,
and DCCP.
o Port Number: The currently unassigned port number(s) the o Port Number: If assignment of port number(s) is desired, either
requester suggests for allocation. If specified and when the currently Unassigned port number(s) the requester suggests for
possible, IANA is encouraged to allocate the suggested number. If allocation or the tag "ANY" MUST be provided. If only a service
not specified, IANA will choose a suitable number from the name is to be assigned, this field MUST be empty. If specific
Registered Ports range. Note that the applicant MUST NOT use the port numbers are requested, IANA is encouraged to allocate the
suggested ports prior to the completion of registration. suggested numbers. If the tag "ANY" is specified, IANA will
choose a suitable number from the Registered Ports range. Note
that the applicant MUST NOT use the suggested ports prior to the
completion of the registration.
o Broadcast, Multicast or Anycast: Indicates whether the protocol o Service Name: A desired unique service name for the service
supports either broadcast, multicast, or anycast network layer associated with the registration request, for use in various
addresses. service selection and discovery mechanisms, MUST be provided.
Valid service names MUST only contain these US-ASCII
[ANSI.X3-4.1986] characters: letters from A to Z, digits from 0 to
9, and hyphens ("-", ASCII 0x2D or decimal 45). They MUST be at
MOST 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. In order to be unique, they
MUST NOT be identical to any currently registered service names in
the IANA registry [REGISTRY]. 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.
o Port Name: The long name (description) of the port. It should o Service Code: A desired unique service code for the service
avoid all but the most well known acronyms. associated with the registration request. Service codes are
specific to the DCCP protocol [I-D.ietf-dccp-serv-codes]; the
request MUST include a desired service code when the registration
requests includes DCCP as a transport protocol, and MUST NOT
include one otherwise.
o Service Name: This short name for the port number, used in o Description: A short description of the service associated with
various service selection and discovery mechanisms, currently the registration request is REQUIRED. It should avoid all but the
including TCPMUX [RFC1078] and DNS SRV resource records [RFC2782]. most well known acronyms.
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 [serv-nam-reg].
o Reference: A reference document describing the protocol or o Reference: A reference document describing the protocol or
application using this port. For registration requests for application using this port, including whether the protocol
Registered Ports, this documentation MUST explain why a port supports either broadcast, multicast, or anycast communication.
number in the Dynamic Ports range is unsuitable for the given For registration requests for Registered Ports, this documentation
application. For registration requests for Well Known Ports, this MUST explain why a port number in the Dynamic Ports range is
documentation MUST explain why a port number in the Registered unsuitable for the given application. For registration requests
Ports or Dynamic Ports ranges is unsuitable. for Well Known Ports, this documentation MUST explain why a port
number in the Registered Ports or Dynamic Ports ranges is
The following rules apply to the port number registry database unsuitable.
maintained by IANA: [database-rules]
o Service Names MUST be unique.
o Service Name MUST exist for all transport protocols.
o Port Number MUST exist for TCP and UDP; it MAY exist for SCTP and
DCCP.
o Transport Protocol MUST exist for all entries.
o Service Code MUST NOT occur for TCP, UDP or SCTP, and MUST occur
for DCCP.
o Port Name MUST exist for all entries.
o Currently valid Registration Contact SHOULD exist for all entries;
it MUST exist for all new entries.
o Reference SHOULD exist for all entries. "Early" registration requests can be made by IETF working groups
without including such a reference document, although it is
RECOMMENDED that at least a reference to an Internet Draft
describing the work in progress is provided.
5.2. Port Number De-Registration 6.2. Port Number and Service Name De-Registration
The original requesters of a granted port number assignment can 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 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 need for it. The port number will be de-registered and will be
marked as reserved [res-vs-unass]. IANA should not re-assign port marked as Reserved. IANA should not re-assign port numbers that have
numbers that have been de-registered until all other available port been de-registered until all other available port numbers in the
numbers in the specific range have been assigned. specific range have been assigned.
Before proceeding with a de-registration, IANA needs to reasonably Before proceeding with a port number de-registration, IANA needs to
establish that the port number is no longer in use. reasonably establish that the value is actually no longer in use.
5.3. Port Number Re-Use 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. It will afterwards
appear in the registry as if it had been created through a service
name registration request that did not include any port numbers.
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.
6.3. Port Number and Service Name Re-Use
If the original requesters of a granted port number assignment no If the original requesters of a granted port number assignment no
longer have a need for the registered number, but would like to re- 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 use it for a different application, they can submit a request to IANA
to do so. to do so.
Logically, port number re-use is to be thought of as a de- Logically, port number re-use is to be thought of as a de-
registration followed by an immediate re-registration of the same registration (Section 6.2) followed by an immediate re-registration
port number for a new application. Consequently, the information (Section 6.1) of the same port number for a new application.
that needs to be provided about the proposed new use of the port Consequently, the information that needs to be provided about the
number is identical to what would need to be provided for a new port proposed new use of the port number is identical to what would need
number allocation for the specific ports range. to be provided for a new port number allocation for the specific
ports range.
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.
IANA needs to carefully review such requests before approving them. IANA needs to carefully review such requests before approving them.
In some instances, the Expert Reviewer will determine that the In some instances, the Expert Reviewer will determine that the
application that the port number was assigned to has found usage application that the port number was assigned to has found usage
beyond the original requester, or that there is a concern that it may beyond the original requester, or that there is a concern that it may
have such users. This determination MUST be made quickly. A have such users. This determination MUST be made quickly. A
community call concerning revocation of a port number (see below) MAY community call concerning revocation of a port number (see below) MAY
be considered, if a broader use of the port number is suspected. be considered, if a broader use of the port number is suspected.
5.4. Port Number Revocation 6.4. Port Number and Service Name Revocation
A port number revocation can be thought of as an IANA-initiated de-
registration (Section 6.2), and has exactly the same effect on the
registry.
Sometimes, it will be clear that a specific port number is no longer Sometimes, it will be clear that a specific port number is no longer
in use and that IANA can de-register it and mark it as reserved [res- in use and that IANA can revoke it and mark it as Reserved. At other
vs-unass2]. At other times, it may be unclear whether a given times, it may be unclear whether a given assigned port number is
assigned port number is still in use somewhere in the Internet. In still in use somewhere in the Internet. In those cases, IANA must
those cases, despite the requester's wish to de-register, IANA must carefully consider the consequences of revoking the port number, and
consider the consequences that de-registering the port number. SHOULD only do so if there is an overwhelming need.
With the help of their IESG-appointed Expert Reviewer, IANA SHALL With the help of their IESG-appointed Expert Reviewer, IANA SHALL
formulate a request to the IESG to issue a four-week community call formulate a request to the IESG to issue a four-week community call
concerning the pending port number revocation. The IESG and IANA, concerning the pending port number revocation. The IESG and IANA,
with the Expert Reviewer's support, SHALL determine promptly after with the Expert Reviewer's support, SHALL determine promptly after
the end of the community call whether revocation should proceed and the end of the community call whether revocation should proceed and
then communicate their decision to the community. This procedure then communicate their decision to the community. This procedure
typically involves similar steps to de-registration except that it is typically involves similar steps to de-registration except that it is
initiated by IANA. initiated by IANA.
5.5. Port Number Transfer Because there is much less danger of exhausting the service name
space compared to the port number space, revoking service names is
The value of port numbers is defined by their careful management as a NOT RECOMMENDED.
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.
5.6. Maintenance Issues
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.
6. Port Number Space Requests
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.
6.1. Request Procedure
All registration requests for a TCP, SCTP, DCCP and/or UDP ports must 6.5. Port Number and Service Name Transfers
contain the following pieces of information:
o Port number tuple: A port number tuple, as described in Section The value of port numbers and service names is defined by their
5.1. The port number would typically be omitted; when provided, it careful management as a shared Internet resource, whereas enabling
indicates a preference for requesting a currently unassigned transfer allows the potential for associated monetary exchanges. As
value. a result, current IANA procedures do not permit port number or
service name assignments to be transferred between parties, even when
they are mutually consenting.
o Port Range: Indicates the port range desired (i.e., Well Known The appropriate alternate procedure is a coordinated de-registration
Ports or Registered Ports). 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.
o Requested Action: One of REGISTER, DEREGISTER, REUSE, With the help of their IESG-appointed Expert Reviewer, IANA SHALL
SVC_NAME_CHANGE, or UPDATE_INFO (port name, registration contact). carefully determine if there is a valid technical, operational or
managerial reason before performing the transfer.
The Well Known Ports are assigned by IANA and cover the range 0-1023. 6.6. Maintenance Issues
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
[RFC5226]. 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.
The Registered Ports are assigned by IANA and on most systems can be The previous procedures help IANA manage the defining properties of
used by ordinary user processes or programs executed by ordinary the port name and service name registry. There are additional
users. The Registered Ports are in the range 1024-49151. procedures which are administrative and help IANA maintain non-
Registration requests for a Registered Port number MUST follow the defining information in a registration. This includes changes to the
"Expert Review" policy of [RFC5226]. Port 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.
7. Security Considerations 7. Security Considerations
The IANA guidelines described in this document do not change the The IANA guidelines described in this document do not change the
security properties of either TCP, SCTP, DCCP or UDP. security properties of either TCP, SCTP, DCCP or UDP.
Assignment of a port number does not in any way imply an endorsement Assignment of a port number or service name does not in any way imply
of an application or product, and the fact that network traffic is an endorsement of an application or product, and the fact that
flowing to or from a registered port number does not mean that it is network traffic is flowing to or from a registered port number does
"good" traffic, or even that it is used by the assigned service. not mean that it is "good" traffic, or even that it is used by the
Firewall and system administrators should choose how to configure assigned service. Firewall and system administrators should choose
their systems based on their knowledge of the traffic in question, how to configure their systems based on their knowledge of the
not whether there is a port number registered or not. traffic in question, not whether there is a port number or service
name registered or not.
8. IANA Considerations 8. IANA Considerations
This document obsoletes Sections 8 and 9.1 of [RFC2780]. Upon This document obsoletes Sections 8 and 9.1 of [RFC2780]. Upon
approval of this document, IANA is requested to adopt the procedures approval of this document, IANA is requested to adopt the procedures
described herein. described herein.
IANA should take immediate actions to resolve inconsistencies raised 8.1. Service Name Consistency
by requirements of this document.
9. Acknowledgments
The text in Appendix A is based on a suggestion by Tom Phelan.
Lars Eggert is partly funded by [TRILOGY], a research project
supported by the European Commission under its Seventh Framework
Program.
This document was prepared using 2-Word-v2.0.template.dot.
10. References
10.1. Normative References
[RFC0768] Postel, J., "User Datagram Protocol", STD 6, RFC 768,
August 1980.
[RFC0793] Postel, J., "Transmission Control Protocol", STD 7, RFC
793, September 1981.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC2780] Bradner, S. and V. Paxson, "IANA Allocation Guidelines For
Values In the Internet Protocol and Related Headers", BCP
37, RFC 2780, March 2000.
[RFC4020] Kompella, K. and A. Zinin, "Early IANA Allocation of
Standards Track Code Points", BCP 100, RFC 4020, February
2005.
[RFC4340] Kohler, E., Handley, M., and S. Floyd, "Datagram Congestion
Control Protocol (DCCP)", RFC 4340, March 2006.
[RFC4727] Fenner, B., "Experimental Values In IPv4, IPv6, ICMPv4,
ICMPv6, UDP, and TCP Headers", RFC 4727, November 2006.
[RFC5226] Narten, T. and H. Alvestrand, "Guidelines for Writing an
IANA Considerations Section in RFCs", BCP 26, RFC 5226, May
2008.
10.2. Informative References
[I-D.touch-tsvwg-port-guidelines] Touch, J., "Guidelines for
Transport Port Use", Work in Progress, Nov. 2008.
[REGISTRY] Internet Assigned Numbers Authority (IANA), "Port
Numbers", http://www.iana.org/assignments/port-numbers.
[RFC0959] Postel, J. and J. Reynolds, "File Transfer Protocol", STD
9, RFC 959, October 1985.
[RFC1078] Lottor, M., "TCP port service Multiplexer (TCPMUX)", RFC
1078, November 1988.
[RFC2782] Gulbrandsen, A., Vixie, P., and L. Esibov, "A DNS RR for
specifying the location of services (DNS SRV)", RFC 2782,
February 2000.
[RFC4342] Floyd, S., Kohler, E., and J. Padhye, "Profile for Datagram
Congestion Control Protocol (DCCP) Congestion Control ID 3:
TCP-Friendly Rate Control (TFRC)", RFC 4342, March 2006.
[RFC4960] Stewart, R., "Stream Control Transmission Protocol", RFC
4960, September 2007.
[RFC5237] Arkko, J. and S. Bradner, "IANA Allocation Guidelines for Section 6.1 defines which character strings are well-formed service
the Protocol Field", BCP 37, RFC 5237, February 2008. names, which until now had not been clearly defined. The definition
on Section 6.1 was chosen to allow maximum compatibility of service
names with various service discovery mechanisms.
[SYSFORM] Internet Assigned Numbers Authority (IANA), "Application Unfortunately, the current port number registry [REGISTRY] contains a
for System (Well Known) Port Number", few assigned service names that do not conform to the new naming
http://www.iana.org/cgi-bin/sys-port-number.pl. rules. In all cases, this is because they contain illegal characters
such as asterisks, dots, plusses, slashes, or underscores. (All
current service names conform to the length requirement of 15
characters or less.)
[TRILOGY] "Trilogy Project",http://www.trilogy-project.org/. Upon approval of this document, IANA SHALL take immediate actions to
resolve these inconsistencies. For any registry assignment with an
illegal service name, IANA SHALL add an alias to the registry that
assigns a well-formed service name for the existing service but
otherwise duplicates the original assignment information. It is
desirable if the alias closely resembles the original service name,
e.g., by remapping underscores to dashes, etc. In the description
field of the new alias, IANA SHALL record that it assigns a well-
formed service name for the previous service and point to the
original assignment. In the description field of the original
assignment, IANA SHALL add a note that the service name is historic,
is not usable with many common service discovery mechanisms, and
provide a reference to the new alias, which can be used in this way.
[USRFORM] Internet Assigned Numbers Authority (IANA), "Application As of 2009-8-5 [REGISTRY], these service names were illegal under the
for User (Registered) Port Number", rules stated in Section 6.1:
http://www.iana.org/cgi-bin/usr-port-number.pl.
Editorial Comments +-----------------+-----------------+----------------+
| 914c/g | EtherNet/IP-1 | EtherNet/IP-2 |
| LiebDevMgmt_A | LiebDevMgmt_C | LiebDevMgmt_DM |
| acmaint_dbd | acmaint_transd | atex_elmd |
| avanti_cdp | badm_priv | badm_pub |
| bdir_priv | bdir_pub | bmc_ctd_ldap |
| bmc_patroldb | boks_clntd | boks_servc |
| boks_servm | broker_service | bues_service |
| canit_store | cedros_fds | cl/1 |
| contamac_icm | corel_vncadmin | csc_proxy |
| cvc_hostd | dbcontrol_agent | dec_dlm |
| dl_agent | documentum_s | dsmeter_iatc |
| dsx_monitor | elpro_tunnel | elvin_client |
| elvin_server | encrypted_admin | erunbook_agent |
| erunbook_server | esri_sde | event_listener |
| flr_agent | gds_db | ibm_wrless_lan |
| iceedcp_rx | iceedcp_tx | iclcnet_svinfo |
| idig_mux | ife_icorp | instl_bootc |
| instl_boots | intel_rci | interhdl_elmd |
| lan900_remote | mapper-ws_ethd | matrix_vnet |
| mdbs_daemon | menandmice_noh | msl_lmd |
| nburn_id | ncr_ccl | nds_sso |
| netmap_lm | nms_topo_serv | notify_srvr |
| novell-lu6.2 | nuts_bootp | nuts_dem |
| ocs_amu | ocs_cmu | pipe_server |
| pra_elmd | printer_agent | redstorm_diag |
| redstorm_find | redstorm_info | redstorm_join |
| resource_mgr | rmonitor_secure | rsvp_tunnel |
| sai_sentlm | sge_execd | sge_qmaster |
| shiva_confsrvr | srvc_registry | stm_pproc |
| subntbcst_tftp | udt_os | universe_suite |
| veritas_pbx | vision_elmd | vision_server |
| whois++ | wrs_registry | z39.50 |
+-----------------+-----------------+----------------+
[database-rules] Lars: Some of these rules below allow entries that 8.2. Port Numbers for SCTP and DCCP Experimentation
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.
[port-reserv] Magnus: The usage of for the above reason reserved port Two Well Known ports, 1021 and 1022, have been reserved for
numbers should probably not have the same rules as the other reserved experimentation UDP and TCP [RFC4727]. This document registers the
ports. Needs discussion if we should separate this properly. I think same port numbers for SCTP and DCCP, and also instructs IANA to
the IETF consultation part will make it difficult the day one automatically register these two port numbers for any new transport
registry runs out of unassigned ones. protocol that will in the future share the port number namespace.
[res-vs-unass] Lars: This used to say "unassigned" instead of Note that these port numbers are meant for temporary experimentation
"reserved". I suggest "reserved", so that IANA has an indication in and development in controlled environments. Before using these port
their list that they need to be careful when re-assigning a numbers, carefully consider the advice in Section 4.1 in this
previously de-registered port. document, as well as in Sections 1 and 1.1 of [RFC3692]. Most
importantly, application developers must request a permanent port
number assignment from IANA as described in Section 6.1 before any
kind of non-experimental deployment.
[res-vs-unass2] Lars: See [res-vs-unass]. +--------------------------------+----------------------------+
| Registration Technical Contact | IESG <iesg@ietf.org> |
| Registration Owner | IETF <iesg@ietf.org> |
| Transport Protocol | SCTP, DCCP |
| Port Number | 1021 |
| Port Name | RFC3692-style Experiment 1 |
| Service Name | exp1 |
| Reference | [RFCyyyy] |
+--------------------------------+----------------------------+
[sctp-dccp-exp] Lars: This document should register ports 1021 and +--------------------------------+----------------------------+
1022 for DCCP and SCTP. Joe: and potentially for all new protocols, | Registration Technical Contact | IESG <iesg@ietf.org> |
as suggested by Alfred? | Registration Owner | IETF <iesg@ietf.org> |
| Transport Protocol | SCTP, DCCP |
| Port Number | 1022 |
| Port Name | RFC3692-style Experiment 2 |
| Service Name | exp2 |
| Reference | [RFCyyyy] |
+--------------------------------+----------------------------+
[serv-nam-reg] Lars: Add citation to the service name registry [RFC Editor Note: Please change "yyyy" to the RFC number allocated to
draft, when it exists this document before publication.]
APPENDIX A: Updates to DCCP Registries 8.3. Updates to DCCP Registries
This document updates the IANA allocation procedures for the DCCP This document updates the IANA allocation procedures for the DCCP
Port Number and DCCP Service Codes Registries as defined in Port Number and DCCP Service Codes Registries as defined in
[RFC4340]. [RFC4340].
A.1. DCCP Service Code Registry 8.3.1. DCCP Service Code Registry
Service Codes are allocated first-come-first-served according to Service Codes are allocated first-come-first-served according to
Section 19.8 of [RFC4340]. This document updates Section 19.8 of Section 19.8 of [RFC4340]. This document updates Section 19.8 of
[RFC4340] by extending the guidelines given there in the following [RFC4340] by extending the guidelines given there in the following
ways: ways:
o IANA MAY assign new Service Codes without seeking Expert Review o IANA MAY assign new Service Codes without seeking Expert Review
using their discretion, but SHOULD seek expert review when a using their discretion, but SHOULD seek expert review when a
request seeks an appreciable number of Service Codes (e.g., more request seeks an appreciable number of Service Codes (e.g., more
than five). than five).
o IANA should feel free to contact the DCCP Expert Reviewer with o IANA should feel free to contact the DCCP Expert Reviewer with
questions on any registry, regardless of the registry policy, for questions on any registry, regardless of the registry policy, for
clarification or if there is a problem with a request [RFC4340]. clarification or if there is a problem with a request [RFC4340].
A.2. DCCP Port Numbers Registry 8.3.2. DCCP Port Numbers Registry
The DCCP ports registry is defined by [RFC4340] in Section 19.9. The DCCP ports registry is defined by [RFC4340] in Section 19.9.
Allocations in this registry require prior allocation of a Service Allocations in this registry require prior allocation of a Service
Code. Not all Service Codes require IANA-registered ports. This Code. Not all Service Codes require IANA-registered ports. This
document updates Section 19.9 of [RFC4340] by extending the document updates Section 19.9 of [RFC4340] by extending the
guidelines given there in the following way: guidelines given there in the following way:
o IANA should normally assign a value in the range 1024-49151 to a o IANA should normally assign a value in the range 1024-49151 to a
DCCP server port. IANA allocation requests to allocate port DCCP server port. IANA allocation requests to allocate port
numbers in the Well Known Ports range (0 through 1023), require numbers in the Well Known Ports range (0 through 1023), require an
IETF action prior to allocation by IANA [RFC4340]. Such action "IETF Review" [RFC5226] prior to allocation by IANA [RFC4340].
typically requires confirmation that the protocol indicated is in
the standards track of the IETF.
Section 19.9 of [RFC4340] requires each DCCP server port assignment Section 19.9 of [RFC4340] requires each DCCP server port assignment
to be associated with at least one Service Code value. This document to be associated with at least one Service Code value. This document
updates [RFC4340] in the following way: updates [RFC4340] in the following way:
o IANA MUST NOT allocate a single Service Code value to more than o IANA MUST NOT allocate a single Service Code value to more than
one DCCP server port. one DCCP server port.
o The set of Service Code values associated with a DCCP server port o The set of Service Code values associated with a DCCP server port
should be recorded in the ports registry. should be recorded in the ports registry.
o A request for additional Service Codes to be associated with an o A request for additional Service Codes to be associated with an
already allocated Port Number requires Expert Review. These already allocated Port Number requires Expert Review. These
requests will normally be accepted when they originate from the requests will normally be accepted when they originate from the
contact associated with the port registration. In other cases, contact associated with the port registration. In other cases,
these applications will be expected to use an unallocated port, these applications will be expected to use an unallocated port,
when this is available. when this is available.
RFC4340] notes that a short port name MUST be associated with each [RFC4340] notes that a short port name MUST be associated with each
DCCP server port that has been registered. This document requires DCCP server port that has been registered. This document requires
that this name MUST be unique. that this name MUST be unique.
9. Acknowledgments
The text in Section 8.3 is based on a suggestion by Tom Phelan.
Lars Eggert is partly funded by [TRILOGY], a research project
supported by the European Commission under its Seventh Framework
Program.
10. References
10.1. Normative References
[ANSI.X3-4.1986]
American National Standards Institute, "Coded Character
Set - 7-bit American Standard Code for Information
Interchange", ANSI X3.4, 1986.
[RFC0768] Postel, J., "User Datagram Protocol", STD 6, RFC 768,
August 1980.
[RFC0793] Postel, J., "Transmission Control Protocol", STD 7,
RFC 793, September 1981.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC2780] Bradner, S. and V. Paxson, "IANA Allocation Guidelines For
Values In the Internet Protocol and Related Headers",
BCP 37, RFC 2780, March 2000.
[RFC3828] Larzon, L-A., Degermark, M., Pink, S., Jonsson, L-E., and
G. Fairhurst, "The Lightweight User Datagram Protocol
(UDP-Lite)", RFC 3828, July 2004.
[RFC4020] Kompella, K. and A. Zinin, "Early IANA Allocation of
Standards Track Code Points", BCP 100, RFC 4020,
February 2005.
[RFC4340] Kohler, E., Handley, M., and S. Floyd, "Datagram
Congestion Control Protocol (DCCP)", RFC 4340, March 2006.
[RFC4727] Fenner, B., "Experimental Values In IPv4, IPv6, ICMPv4,
ICMPv6, UDP, and TCP Headers", RFC 4727, November 2006.
[RFC5226] Narten, T. and H. Alvestrand, "Guidelines for Writing an
IANA Considerations Section in RFCs", BCP 26, RFC 5226,
May 2008.
10.2. Informative References
[I-D.cheshire-dnsext-dns-sd]
Cheshire, S. and M. Krochmal, "DNS-Based Service
Discovery", draft-cheshire-dnsext-dns-sd-05 (work in
progress), September 2008.
[I-D.cheshire-dnsext-multicastdns]
Cheshire, S. and M. Krochmal, "Multicast DNS",
draft-cheshire-dnsext-multicastdns-07 (work in progress),
September 2008.
[I-D.ietf-dccp-serv-codes]
Fairhurst, G., "The DCCP Service Code",
draft-ietf-dccp-serv-codes-11 (work in progress),
May 2009.
[REGISTRY]
Internet Assigned Numbers Authority (IANA), "Port
Numbers", http://www.iana.org/assignments/port-numbers.
[RFC0959] Postel, J. and J. Reynolds, "File Transfer Protocol",
STD 9, RFC 959, October 1985.
[RFC1034] Mockapetris, P., "Domain names - concepts and facilities",
STD 13, RFC 1034, November 1987.
[RFC1078] Lottor, M., "TCP port service Multiplexer (TCPMUX)",
RFC 1078, November 1988.
[RFC2782] Gulbrandsen, A., Vixie, P., and L. Esibov, "A DNS RR for
specifying the location of services (DNS SRV)", RFC 2782,
February 2000.
[RFC3692] Narten, T., "Assigning Experimental and Testing Numbers
Considered Useful", BCP 82, RFC 3692, January 2004.
[RFC4342] Floyd, S., Kohler, E., and J. Padhye, "Profile for
Datagram Congestion Control Protocol (DCCP) Congestion
Control ID 3: TCP-Friendly Rate Control (TFRC)", RFC 4342,
March 2006.
[RFC4960] Stewart, R., "Stream Control Transmission Protocol",
RFC 4960, September 2007.
[RFC5237] Arkko, J. and S. Bradner, "IANA Allocation Guidelines for
the Protocol Field", BCP 37, RFC 5237, February 2008.
[SRVTYPE] "DNS SRV (RFC 2782) Service Types",
http://www.dns-sd.org/ServiceTypes.html.
[SYSFORM] Internet Assigned Numbers Authority (IANA), "Application
for System (Well Known) Port Number",
http://www.iana.org/cgi-bin/sys-port-number.pl.
[TRILOGY] "Trilogy Project", http://www.trilogy-project.org/.
[USRFORM] Internet Assigned Numbers Authority (IANA), "Application
for User (Registered) Port Number",
http://www.iana.org/cgi-bin/usr-port-number.pl.
Authors' Addresses Authors' Addresses
Michelle Cotton Michelle Cotton
Internet Corporation for Assigned Names and Numbers Internet Corporation for Assigned Names and Numbers
4676 Admiralty Way, Suite 330 4676 Admiralty Way, Suite 330
Marina del Rey, CA 90292 Marina del Rey, CA 90292
USA USA
Phone: +1 310 823 9358 Phone: +1 310 823 9358
Email: michelle.cotton@icann.org Email: michelle.cotton@icann.org
skipping to change at page 21, line 28 skipping to change at page 23, line 30
Nokia Research Center Nokia Research Center
P.O. Box 407 P.O. Box 407
Nokia Group 00045 Nokia Group 00045
Finland Finland
Phone: +358 50 48 24461 Phone: +358 50 48 24461
Email: lars.eggert@nokia.com Email: lars.eggert@nokia.com
URI: http://research.nokia.com/people/lars_eggert/ URI: http://research.nokia.com/people/lars_eggert/
Allison Mankin Allison Mankin
Johns Hopkins Univ. Johns Hopkins University
USA
Phone: +1 301 728 7199 Phone: +1 301 728 7199
Email: mankin@psg.com Email: mankin@psg.com
URI: http://www.psg.com/~mankin/ URI: http://www.psg.com/~mankin/
Magnus Westerlund
Ericsson
Torshamsgatan 23
Stockholm 164 80
Sweden
Phone: +46 8 719 0000
Email: magnus.westerlund@ericsson.com
Joe Touch Joe Touch
USC/ISI USC/ISI
4676 Admiralty Way 4676 Admiralty Way
Marina del Rey, CA 90292 Marina del Rey, CA 90292
USA USA
Phone: +1 310 448 9151 Phone: +1 310 448 9151
Email: touch@isi.edu Email: touch@isi.edu
URI: http://www.isi.edu/touch URI: http://www.isi.edu/touch
Magnus Westerlund
Ericsson
Torshamsgatan 23
Stockholm 164 80
Sweden
Full Copyright Statement Phone: +46 8 719 0000
Email: magnus.westerlund@ericsson.com
Copyright (C) The IETF Trust (2008).
This document is subject to the rights, licenses and restrictions
contained in BCP 78, and except as set forth therein, the authors
retain all their rights.
This document and the information contained herein are provided on an
"AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS
OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY, THE IETF TRUST AND
THE INTERNET ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS
OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF
THE INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED
WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
Intellectual Property Statement
The IETF takes no position regarding the validity or scope of any
Intellectual Property Rights or other rights that might be claimed to
pertain to the implementation or use of the technology described in
this document or the extent to which any license under such rights
might or might not be available; nor does it represent that it has
made any independent effort to identify any such rights. Information
on the procedures with respect to rights in RFC documents can be
found in BCP 78 and BCP 79.
Copies of IPR disclosures made to the IETF Secretariat and any
assurances of licenses to be made available, or the result of an
attempt made to obtain a general license or permission for the use of
such proprietary rights by implementers or users of this
specification can be obtained from the IETF on-line IPR repository at
http://www.ietf.org/ipr.
The IETF invites any interested party to bring to its attention any
copyrights, patents or patent applications, or other proprietary
rights that may cover technology that may be required to implement
this standard. Please address the information to the IETF at
ietf-ipr@ietf.org.
 End of changes. 111 change blocks. 
493 lines changed or deleted 667 lines changed or added

This html diff was produced by rfcdiff 1.35. The latest version is available from http://tools.ietf.org/tools/rfcdiff/