One document matched: draft-ietf-tsvwg-iana-ports-08.txt
Differences from draft-ietf-tsvwg-iana-ports-07.txt
Transport Area Working Group M. Cotton
Internet-Draft ICANN
Updates: 2780, 2782, 3828, 4340, L. Eggert
4960 (if approved) Nokia
Intended status: BCP J. Touch
Expires: April 28, 2011 USC/ISI
M. Westerlund
Ericsson
S. Cheshire
Apple
October 25, 2010
Internet Assigned Numbers Authority (IANA) Procedures for the Management
of the Service Name and Transport Protocol Port Number Registry
draft-ietf-tsvwg-iana-ports-08
Abstract
This document defines the procedures that the Internet Assigned
Numbers Authority (IANA) uses when handling registration and other
requests related to the Service Name and Transport Protocol Port
Number Registry. It also discusses the rationale and principles
behind these procedures and how they facilitate the long-term
sustainability of the registry.
This document updates IANA's procedures by obsoleting Sections 8 and
9.1 of the IANA allocation guidelines [RFC2780], and it updates the
IANA allocation procedures for UDP-Lite [RFC3828], DCCP [RFC4340] and
SCTP [RFC4960]. It also updates the DNS SRV specification [RFC2782]
to clarify what a service name is and how it is registered.
Status of this Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet-
Drafts is at http://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress."
This Internet-Draft will expire on April 28, 2011.
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Copyright Notice
Copyright (c) 2010 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
(http://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents
carefully, as they describe your rights and restrictions with respect
to this document. Code Components extracted from this document must
include Simplified BSD License text as described in Section 4.e of
the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License.
This document may contain material from IETF Documents or IETF
Contributions published or made publicly available before November
10, 2008. The person(s) controlling the 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.
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 4
2. Motivation . . . . . . . . . . . . . . . . . . . . . . . . . . 5
3. Background . . . . . . . . . . . . . . . . . . . . . . . . . . 6
4. Conventions Used in this Document . . . . . . . . . . . . . . 7
5. Service Names . . . . . . . . . . . . . . . . . . . . . . . . 8
5.1. Service Name Syntax . . . . . . . . . . . . . . . . . . . 9
5.2. Service Name Usage in DNS SRV Records . . . . . . . . . . 10
6. Port Number Ranges . . . . . . . . . . . . . . . . . . . . . . 10
6.1. Service names and Port Numbers for Experimentation . . . . 11
7. Principles for Service Name and Transport Protocol Port
Number Registry Management . . . . . . . . . . . . . . . . . . 12
7.1. Past Principles . . . . . . . . . . . . . . . . . . . . . 12
7.2. Updated Principles . . . . . . . . . . . . . . . . . . . . 13
8. IANA Procedures for Managing the Service Name and
Transport Protocol Port Number Registry . . . . . . . . . . . 15
8.1. Service Name and Port Number Registration . . . . . . . . 16
8.2. Service Name and Port Number De-Registration . . . . . . . 20
8.3. Service Name and Port Number Re-Use . . . . . . . . . . . 20
8.4. Service Name and Port Number Revocation . . . . . . . . . 21
8.5. Service Name and Port Number Transfers . . . . . . . . . . 21
8.6. Maintenance Issues . . . . . . . . . . . . . . . . . . . . 22
8.7. Disagreements . . . . . . . . . . . . . . . . . . . . . . 22
9. Security Considerations . . . . . . . . . . . . . . . . . . . 22
10. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 22
10.1. Service Name Consistency . . . . . . . . . . . . . . . . . 23
10.2. Port Numbers for SCTP and DCCP Experimentation . . . . . . 25
10.3. Updates to DCCP Registries . . . . . . . . . . . . . . . . 26
11. Contributors . . . . . . . . . . . . . . . . . . . . . . . . . 27
12. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 27
13. References . . . . . . . . . . . . . . . . . . . . . . . . . . 28
13.1. Normative References . . . . . . . . . . . . . . . . . . . 28
13.2. Informative References . . . . . . . . . . . . . . . . . . 29
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 30
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1. Introduction
For many years, the allocation of new service names and port number
values for use with the Transmission Control Protocol (TCP) [RFC0793]
and the User Datagram Protocol (UDP) [RFC0768] have had less than
clear guidelines. New transport protocols have been added - the
Stream Control Transmission Protocol (SCTP) [RFC4960] and the
Datagram Congestion Control Protocol (DCCP) [RFC4342] - and new
mechanisms like DNS SRV records [RFC2782] have been developed, each
with separate registries and separate guidelines. The community also
recognized the need for additional procedures beyond just assignment;
notably modification, revocation, and release.
A key element of the procedural streamlining specified in this
document is to establish identical assignment procedures for all IETF
transport protocols. This document brings the IANA procedures for
TCP and UDP in line with those for SCTP and DCCP, resulting in a
single process that requesters and IANA follow for all requests for
all transport protocols, including future protocols not yet defined.
In addition to detailing the IANA procedures for the initial
assignment of service names and 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 the procedure by which IANA can unilaterally revoke a prior port
number assignment. Section 8 discusses the specifics of these
procedures and processes that requesters and IANA follow for all
requests for all current and future transport protocols.
IANA is the authority for assigning service names and port numbers.
The registries that are created to store these registrations are
maintained by IANA. For protocols developed by IETF working groups,
IANA now also offers a method for the "early assignment" [RFC4020] of
service names and port numbers, as described in Section 8.1.
This document updates IANA's procedures for UDP and TCP port numbers
by obsoleting Sections 8 and 9.1 of the IANA allocation guidelines
[RFC2780]. (Note that other sections of the IANA allocation
guidelines, relating to the protocol field values in IPv4 header,
were also updated in February 2008 [RFC5237].) This document also
updates the IANA allocation procedures for DCCP [RFC4340] and SCTP
[RFC4960].
The Lightweight User Datagram Protocol (UDP-Lite) [RFC5237] shares
the port space with UDP. The UDP-Lite specification says: "UDP-Lite
uses the same set of port number values assigned by the IANA for use
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by UDP". Thus the update of UDP procedures result in an update also
of the UDP-Lite procedures.
This document also clarifies what a service name is and how it is
registered. This will impact the DNS SRV specification [RFC2782],
because that specification merely makes a brief mention that the
symbolic names of services are defined in "Assigned Numbers"
[RFC1700], without stating to which section it refers within that
230-page document. The DNS SRV specification may have been referring
to the list of Port Assignments (known as /etc/services on Unix), or
to the "Protocol And Service Names" section, or to both, or to some
other section. Furthermore, "Assigned Numbers" is now obsolete
[RFC3232] and has been replaced by on-line registries
[PORTREG][PROTSERVREG].
The development of new transport protocols is a major effort that the
IETF does not undertake very often. If a new transport protocol is
standardized in the future, for consistency it is expected to follow
as much as possible the guidelines and practices around using service
names and port numbers.
2. Motivation
Information about the registration procedures for the port registry
has existed in three locations: the forms for requesting port number
registrations on the IANA web site [SYSFORM] [USRFORM], an
introductory text section in the file listing the port number
registrations themselves [PORTREG], and two brief sections of the
IANA Allocation Guidelines [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 Resource Records (RRs) was introduced, the
requirement by IANA to only assign service names and port numbers in
combination, led to the creation of an ad hoc service name registry
outside of the control of IANA [SRVREG].
This document aggregates all this scattered information into a single
reference that aligns and clearly defines the management procedures
for both service names and port numbers. It gives more detailed
guidance to prospective requesters of service names and ports than
the existing documentation, and it streamlines the IANA procedures
for the management of the registry, so that requests can be completed
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in a timely manner.
This document defines rules for registration of service names without
associated port numbers, for such usages as DNS SRV records
[RFC2782], which was not possible under the previous IANA procedures.
The document also merges service name registrations from the non-IANA
ad hoc registry [SRVREG] and from the IANA "Protocol and Service
Names" registry [PROTSERVREG] into the IANA "Service Name and
Transport Protocol Port Number" registry [PORTREG], which from here
on is the single authoritative registry for service names and port
numbers.
An additional purpose of this document is to describe the principles
that guide the IETF and IANA in their role as the long-term joint
stewards of the service name and port number registry. TCP and UDP
have had remarkable success over the last decades. Thousands of
applications and application-level protocols have service names and
ports assigned 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 7
discusses these principles in detail.
3. Background
The Transmission Control Protocol (TCP) [RFC0793] and the User
Datagram Protocol (UDP) [RFC0768] have enjoyed a remarkable success
over the decades as the two most widely used transport protocols on
the Internet. They have relied on the concept of "ports" as logical
entities for Internet communication. Ports serve two purposes:
first, they provide a demultiplexing identifier to differentiate
transport sessions between the same pair of endpoints, and second,
they may also identify the application protocol and associated
service to which processes bind. Newer transport protocols, such as
the Stream Control Transmission Protocol (SCTP) [RFC4960] and the
Datagram Congestion Control Protocol (DCCP) [RFC4342] have also
adopted the concept of ports for their communication sessions and use
16-bit port numbers in the same way as TCP and UDP (and UDP-Lite
[RFC3828], a variant of UDP).
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 associated service names such as
"telnet" for port number 23 and "http" (as well as "www" and "www-
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http") for port number 80.
Hosts running services, hosts accessing services on other hosts, and
intermediate devices (such as firewalls and NATs) that restrict
services need to agree on which service corresponds to a particular
destination port. Although this is ultimately a local decision with
meaning only between the endpoints of a connection, it is common for
many services to have a default port upon which those servers usually
listen, when possible, and these ports are recorded by the Internet
Assigned Numbers Authority (IANA) through the service name and port
number registry [PORTREG].
Over time, the assumption that a particular port number necessarily
implies a particular service may become less true. For example,
multiple instances of the same service on the same host cannot
generally listen on the same port, and multiple hosts behind the same
NAT gateway cannot all have a mapping for the same port on the
external side of the NAT gateway, whether using static port mappings
configured by hand by the user, or dynamic port mappings configured
automatically using a port mapping protocol like NAT Port Mapping
Protocol (NAT-PMP) [I-D.cheshire-nat-pmp] or Internet Gateway Device
(IGD) [IGD].
Applications may use numeric port numbers directly, look up port
numbers based on service names via system calls such as
getservbyname() on UNIX, look up port numbers by performing queries
for DNS SRV records [RFC2782][I-D.cheshire-dnsext-dns-sd], or
determine port numbers in a variety of other ways like the TCP Port
Service Multiplexer (TCPMUX) [RFC1078].
Designers of applications and application-level protocols may apply
to IANA for an assigned service name and port number for a specific
application, and may - after successful registration - assume that no
other application will use that service name or port number for its
communication sessions. Alternatively, application designers may
also ask for only an assigned service name, if their application does
not require a fixed port number. The latter alternative is
encouraged when possible, in order to conserve the more limited port
number space. This is applicable, for example, to applications that
use DNS SRV records to look up port numbers at runtime.
4. Conventions Used in this Document
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 "Key words for use in
RFCs to Indicate Requirement Levels" [RFC2119].
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5. Service Names
Service names are the unique key in the Service Name and Transport
Protocol Port Number Registry. This unique symbolic name for a
service may also be used for other purposes, such as in DNS SRV
records [RFC2782]. Within the registry, this unique key ensures that
different services can be unambiguously distinguished, thus
preventing name collisions and avoiding confusion about who is the
Registrant for a particular entry.
There may be more than one service name associated with a particular
transport protocol and port. There are three ways that such service
name overloading can occur:
o Overloading occurs when one service is an extension of another
service, and an in-band mechanism exists for determining if the
extension is present or not. One example is port 3478, which has
the service name aliases "stun" and "turn". TURN [RFC5766] is an
extension to the STUN [RFC5389] service. TURN-enabled clients
wishing to locate TURN servers could attempt to discover "stun"
services and then check in-band if the server supports TURN, but
this would be inefficient. Enabling them to directly query for
"turn" servers by name is a better approach. (Note that TURN
servers in this case should also be locatable via a "stun"
discovery, because every TURN server is also a STUN server.)
o By historical accident the service name "http" corresponds to the
same port number as "www" and "www-http". When used in SRV
records [RFC2782], and similar service discovery mechanisms only
the service name "http" should be used, not these additional
names. If a server were to advertise "www" then it would not be
discovered by clients browsing for "http". Advertising or
browsing for the aliases as well as the primary service name would
be inefficient, and achieves nothing that it not already achieved
by using the service name "http" exclusively.
o As indicated in this document, in Section 10.1, to enable legacy
names to be replaced with names consistent with the syntax this
document prescribes. In this case, only the new name should be
used in SRV records, both to avoid the same issues as with
historical cases of multiple names, as well as because the legacy
names are incompatible with SRV record use.
For future assignments, applications will not be permitted that
merely request a new name exactly duplicating an existing service.
Having multiple names for the same service serves no purpose.
Implementers are requested to inform IANA if they discover other
cases where a single service has multiple names, so that one name may
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be recorded as the primary name for service discovery purposes.
Service names are assigned on a "first come, first served" basis, as
described in Section 8.1. Names should be brief and informative,
avoiding words or abbreviations that are redundant in the context of
the registry (e.g., "port", "service", "protocol", etc.) Names
referring to discovery services, e.g., using multicast or broadcast
to identify endpoints capable of a given service, SHOULD use an
easily identifiable suffix (e.g., "-disc").
5.1. Service Name Syntax
Valid service names are hereby normatively defined as follows:
o MUST be at least 1 character and no more than 15 characters long
o MUST contain only US-ASCII [ANSI.X3-4.1986] letters 'A' - 'Z' and
'a' - 'z', digits '0' - '9', and hyphens ('-', ASCII 0x2D or
decimal 45)
o MUST contain at least one letter ('A' - 'Z' or 'a' - 'z')
o MUST NOT begin or end with a hyphen
o hyphens MUST NOT be adjacent to other hyphens
The reason for requiring at least one letter is to avoid service
names like "23" (could be confused with a numeric port number) or
"6000-6063" (could be confused with a numeric port number range).
Although service names may contain both upper-case and lower-case
letters, case is ignored for comparison purposes, so both "http" and
"HTTP" denote the same service.
Service names are purely opaque identifiers, and no semantics are
implied by any superficial structure that a given service name may
appear to have. For example, a company called "Example" may choose
to register service names "Example-Foo" and "Example-Bar" for its
"Foo" and "Bar" products, but the "Example" company can't claim to
"own" all service names beginning with "Example-", they can't prevent
someone else registering "Example-Baz" for a different service, and
they can't prevent other developers from using the "Example-Foo" and
"Example-Bar" service types in order to interoperate with the "Foo"
and "Bar" products. Technically speaking, in service discovery
protocols, service names are merely a series of byte values on the
wire; for the mnemonic convenience of human developers it can be
convenient to interpret those byte values as human-readable ascii
characters, but software should treat them as purely opaque
identifiers and not attempt to parse them for any additional embedded
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meaning.
In approximately 98% of cases, the new "service name" is exactly the
same as the old historic "short name" from the IANA web forms
[SYSFORM] [USRFORM]. In approximately 2% of cases, the new "service
name" is derived from the old historic "short name" as described
below in Section 10.1.
The rules for valid service names, excepting the limit of 15
characters maximum, are also expressed below (as a non-normative
convenience) using ABNF [RFC5234].
SRVNAME = *(1*DIGIT [HYPHEN]) ALPHA *([HYPHEN] ALNUM)
ALNUM = ALPHA / DIGIT ; A-Z, a-z, 0-9
HYPHEN = %x2d ; "-"
ALPHA = %x41-5A / %x61-7A ; A-Z / a-z [RFC5234]
DIGIT = %x30-39 ; 0-9 [RFC5234]
5.2. Service Name Usage in DNS SRV Records
The DNS SRV specification [RFC2782] states that the Service Label
part of the owner name of a DNS SRV record includes a "Service"
element, described as "the symbolic name of the desired service", but
as discussed above, it is not clear precisely what this means.
This document clarifies that the Service Label MUST be a service name
as defined herein. The service name SHOULD be registered with IANA
and recorded in the Service Name and Transport Protocol Port Number
Registry [PORTREG].
The details of using Service Names in SRV Service Labels are
specified in the DNS SRV specification [RFC2782]. This document does
not change that specification.
6. Port Number Ranges
TCP, UDP, UDP-Lite, SCTP and DCCP use 16-bit namespaces for their
port number registries. The port registries for all these transport
protocols are subdivided into three ranges of numbers, and
Section 8.1.1 describes the IANA procedures for each range in detail:
o the System Ports, also known as the Well Known Ports, from 0-1023
(assigned by IANA)
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o the User Ports, also known as the Registered Ports, from 1024-
49151 (assigned by IANA)
o the Dynamic Ports, also known as the Private Ports, from 49152-
65535 (never assigned)
Of the assignable port ranges (System Ports and User Ports, i.e.,
port numbers 0-49151), individual port numbers are in one of three
states at any given time:
o Assigned: Assigned port numbers are currently allocated to the
service indicated in the registry.
o Unassigned: Unassigned port numbers are currently available for
assignment upon request, as per the procedures outlined in this
document.
o 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.
In order to keep the size of the registry manageable, IANA typically
only records the Assigned and Reserved service names and port numbers
in the registry. Unassigned values are typically not explicitly
listed. (There are an near-infinite number of Unassigned service
names and enumerating them all would not be practical.)
As a data point, when this document was written, approximately 76% of
the TCP and UDP System Ports were assigned, and approximately 9% of
the User Ports were assigned. (As noted, Dynamic Ports are never
assigned.)
6.1. Service names and Port Numbers for Experimentation
Of the System Ports, two TCP and UDP port numbers (1021 and 1022),
together with their respective service names ("exp1" and "exp2"),
have been assigned for experimentation with new applications and
application-layer protocols that require a port number in the
assigned ports ranges [RFC4727].
Please refer to Sections 1 and 1.1 of "Assigning Experimental and
Testing Numbers Considered Useful" [RFC3692] for how these
experimental port numbers are to be used.
This document registers the same two service names and port numbers
for experimentation with new application-layer protocols over SCTP
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and DCCP in Section 10.2.
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.
7. Principles for Service Name and Transport Protocol Port Number
Registry Management
Management procedures for the service name and transport protocol
port number registry include allocation of service names and port
numbers upon request, as well as management of information about
existing allocations. The latter includes maintaining contact and
description information about assignments, revoking abandoned
assignments, and redefining assignments when needed. Of these
procedures, careful port number allocation is most critical, in order
to continue to conserve the remaining port numbers.
As noted earlier, only about 9% of the User Port space is currently
assigned. The current rate of assignment is approximately 400 ports
per year, and has remained steady for the past 8 years. At that
rate, if similar conservation continues, this resource will sustain
another 85 years of assignment - without the need to resort to
reassignment of released values or revocation. The namespace
available for service names is much larger, which allows for simpler
management procedures.
7.1. Past Principles
Before the publication of this document, the principles of service
name and port number management followed a few mostly-undocumented
guidelines. They are recorded here for historical purposes, and this
document updates them in Section 7.2. These principles were:
o TCP and UDP ports were simultaneously allocated when either was
requested
o Port numbers were the primary allocation; service names were
informative only, and did not have a well-defined syntax
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o Port numbers were conserved informally, and sometimes
inconsistently (e.g., some services were allocated ranges of many
port numbers even where not strictly necessary)
o SCTP and DCCP service name and port number registries were managed
separately from the TCP/UDP registries
o Service names could not be assigned in the old ports registry
without assigning an associated port number at the same time
This document clarifies and aligns these guidelines in order to more
conservatively manage the limited remaining port number space and to
enable and promote the use of service names for service
identification without associated port numbers, where possible.
7.2. Updated Principles
This section summarizes the basic principles by which IANA handles
the Service Name and Transport Protocol Port Number Registry, and
attempts to conserve the port number space. This description is
intended to inform applicants requesting service names and port
numbers. IANA are not required to be bound by these principles when
handling requests; other factors may come into play, and exceptions
may occur where deemed in the best interest of the Internet.
IANA will begin assigning service names that do not request an
associated port number allocation under a simple "First Come, First
Served" policy [RFC5226]. IANA MAY, at its discretion, refer service
name requests to "Expert Review" in cases of mass registrations or
other situations where IANA believes expert review is advisable.
The basic principle of service name and port number registry
management is to conserve use of the port space where possible.
Extensions to support larger port number spaces would require
changing many core protocols of the current Internet in a way that
would not be backward compatible and interfere with both current and
legacy applications. To help ensure this conservation the policy for
any registration request for port number allocations uses the "Expert
Review" policy [RFC5226].
Conservation of the port number space is required because this space
is a limited resource, so applications are expected to participate in
the traffic demultiplexing process where feasible. The port numbers
are expected to encode as little information as possible that will
still enable an application to perform further demultiplexing by
itself. In particular:
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o IANA will allocate only one assigned port number per service or
application
o IANA will allocate only one assigned port number for all versions
of a service (e.g., running the service with or without a security
mechanism, or for updated variants of a service)
o IANA will allocate only one assigned port number for all different
types of device using or participating in the same service
o IANA will allocate port numbers only for the transport protocol(s)
explicitly named in a registration request
o IANA may recover unused port numbers, via the new procedures of
de-registration, revocation, and transfer
Where possible, a given service is expected to demultiplex messages
if necessary. For example, applications and protocols are expected
to include in-band version information, so that future versions of
the application or protocol can share the same allocated port.
Applications and protocols are also expected to be able to
efficiently use a single allocated port for multiple sessions, either
by demultiplexing multiple streams within one port, or using the
allocated port to coordinate using dynamic ports for subsequent
exchanges (e.g., in the spirit of FTP [RFC0959]).
Ports are used in various ways, notably:
o as endpoint process identifiers
o as application protocol identifiers
o for firewall filtering purposes
Both the process identifier and the protocol identifier uses suggest
that anything a single process can demultiplex, or that can be
encoded into a single protocol, should be. The firewall filtering
use suggests that some uses that could be multiplexed or encoded
could instead be separated to allow for easier firewall management.
Note that this latter use is much less sound, because port numbers
have meaning only for the two endpoints involved in a connection, and
drawing conclusions about the service that generated a given flow
based on observed port numbers is not always reliable. Further,
previous separation of protocol variants based on security
capabilities (e.g., HTTP on TCP port 80 vs. HTTPS on TCP port 443) is
not recommended for new protocols, because all new protocols should
be security-capable and capable of negotiating the use of security
in-band.
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IANA will begin assigning port numbers for only those transport
protocols explicitly included in a registration request. This ends
the long-standing practice of automatically assigning a port number
to an application for both TCP and a UDP, even if the request is for
only one of these transport protocols. The new allocation procedure
conserves resources by allocating a port number to an application for
only those transport protocols (TCP, UDP, SCTP and/or DCCP) it
actually uses. The port number will be marked as Reserved - instead
of Assigned - in the port number registries of the other transport
protocols. When applications start supporting the use of some of
those additional transport protocols, the Registrant for the
registration MUST request IANA to convert the reservation into a
proper assignment. An application MUST NOT assume that it can use a
port number assigned to it for use with one transport protocol with
another transport protocol without asking IANA to convert the
reservation into an assignment.
When the available pool of unassigned numbers has run out in a ports
range, it will be necessary for IANA to consider the Reserved ports
for assignment. This is part of the motivation for not automatically
assigning ports for transport protocols other than the requested
one(s). This will allow more ports to be available for assignment
when that time comes. To help conserve ports, application developers
should register only the transport protocols that their application
currently uses.
Conservation of port numbers is improved by procedures that allow
previously allocated port numbers to become Unassigned, either
through de-registration or through revocation, and by a procedure
that lets application designers transfer an allocated but unused port
number to a new application. Section 8 describes these procedures,
which until now were undocumented. Port number conservation is also
improved by recommending that applications that do not require an
allocated port should register only a service name without an
associated port number.
8. IANA Procedures for Managing the Service Name and Transport Protocol
Port Number Registry
This section describes the process for handling requests associated
with IANA's management of the Service Name and Transport Protocol
Port Number Registry. Such requests include initial registration,
de-registration, re-use, changes to the service name, and updates to
the contact information or description associated with an assignment.
Revocation is as additional process, initiated by IANA.
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8.1. Service Name and Port Number Registration
Registration refers to the allocation of service names or port
numbers to applicants. All such registrations are made from service
names or port numbers that are Unassigned or Reserved at the time of
the allocation. Unassigned names and numbers are allocated according
to the rules described in Section 8.1.1 below. Reserved numbers and
names are assigned only by Standards Action or IESG Approval, and
MUST accompanied by a statement explaining the reason a Reserved
number or name is appropriate for this action.
When a registration for one or more transport protocols is approved,
the port number for any non-requested transport protocol(s) will be
marked as Reserved. IANA SHOULD NOT assign that port number to any
other application or service until no other port numbers remain
Unassigned in the requested range. The current Registrant for a port
number MAY register these Reserved port numbers for other transport
protocols when needed.
A service name or port number registration request contains the
following information. The service name is the unique identifier of
a given service:
Service Name (REQUIRED)
Transport Protocol(s) (REQUIRED)
Registrant (REQUIRED)
Contact (REQUIRED)
Description (REQUIRED)
Reference (REQUIRED)
Port Number (OPTIONAL)
Service Code (REQUIRED for DCCP only)
Known Unauthorized Uses (OPTIONAL)
Assignment Notes (OPTIONAL)
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o Service Name: A desired unique service name for the service
associated with the registration request MUST be provided, for use
in various service selection and discovery mechanisms (including,
but not limited to, DNS SRV records [RFC2782]). The name MUST be
compliant with the syntax defined in Section 5.1. In order to be
unique, they MUST NOT be identical to any currently assigned
service name in the IANA registry [PORTREG]. Service names are
case-insensitive; they may be provided and entered into the
registry with mixed case for clarity, but for the comparison
purposes the case is ignored.
o Transport Protocol(s): The transport protocol(s) for which a
allocation is requested MUST be provided. This field is currently
limited to one or more of TCP, UDP, SCTP, and DCCP. Requests
without any port allocation and only a service name are still
required to indicate which protocol the service uses.
o Registrant: Name and email address of the Registrant. This is
REQUIRED. The Registrant is the Organization or Company
responsible for the initial registration. For registrations done
through IETF-published RFCs, the Registrant will be the IESG.
o Contact: Name and email address of the Contact person for the
registration. This is REQUIRED. The Contact person is the
responsible person for the Internet community to send questions
to. This person would also be authorized to submit changes on
behalf of the Registrant; in cases of conflict between the
Registrant and the Contact, the Registrant decisions take
precedence. Additional address information MAY be provided. For
registrations done through IETF-published RFCs, the Contact will
be the IESG.
o Description: A short description of the service associated with
the registration request is REQUIRED. It should avoid all but the
most well-known acronyms.
o Reference: A description of (or a reference to a document
describing) the protocol or application using this port. The
description must state whether the protocol uses broadcast,
multicast, or anycast communication.
For registrations requesting only a Service Name, or a Service
Name and User Port, a statement that the protocol is proprietary
and not publicly documented is also acceptable provided that the
required information regarding use of broadcast, multicast, or
anycast is given.
For registration requests for a User Port, the registration
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request MUST explain why a port number in the Dynamic Ports range
is unsuitable for the given application.
For registration requests for a System Port, the registration
request MUST explain why a port number in the User Ports or
Dynamic Ports ranges is unsuitable, and a reference to a stable
protocol specification document MUST be provided. For requests
from IETF Working Groups, IANA MAY accept "early registration"
[RFC4020] requests referencing a sufficiently stable Internet
Draft instead of a published Standards-Track RFC.
o Port Number: If assignment of a port number is desired, either the
currently Unassigned or Reserved port number the requester
suggests for allocation, or indication of which port range, user
or system, that the requester requires, MUST be provided. If only
a service name is to be assigned, this field is left empty. If a
specific port number is requested, IANA is encouraged to allocate
the requested number. If a range is specified, IANA will choose a
suitable number from the User or System Ports ranges. Note that
the applicant MUST NOT use the requested port prior to the
completion of the registration.
o Service Code: If the registration request includes DCCP as a
transport protocol then the request MUST include a desired unique
DCCP service code [RFC5595], and MUST NOT include a requested DCCP
service code otherwise. Section 19.8 of the DCCP specification
[RFC4340] defines requirements and rules for allocation, updated
by this document.
o Known Unauthorized Uses: A list of uses by applications or
organizations who are not the Registrant. This list may be
augmented by IANA after assignment when unauthorized uses are
reported.
o Assignment Notes: Indications of owner/name change, or any other
assignment process issue. This list may be updated by IANA after
assignment to help track changes to an assignment, e.g., de-
registration, owner/name changes, etc.
If the registration request is for the addition of a new transport
protocol to an already assigned service name, IANA needs to confirm
with the Registrant for the existing assignment whether this addition
is appropriate.
If the registration request is for a service name overloading a port
number (see Section 5), IANA needs to confirm with the Registrant for
the existing service name whether the registration of the overloading
is appropriate.
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When IANA receives a registration request - containing the above
information - that is requesting a port number, IANA SHALL initiate
an "Expert Review" [RFC5226] in order to determine whether an
assignment should be made. For requests that are not requesting a
port number, IANA SHOULD assign the service name under a simple
"First Come First Served" policy [RFC5226].
8.1.1. Variances for Specific Port Number Ranges
Section 6 describes the different port number ranges. It is
important to note that IANA applies slightly different procedures
when managing the different port ranges of the service name and port
number registry:
o Ports in the Dynamic Ports range (49152-65535) have been
specifically set aside for local and dynamic use and cannot be
assigned through IANA. Application software may simply use them
for communication without any sort of registration. On the other
hand, application software 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.
o Ports in the User Ports range (1024-49151) are available for
registration through IANA, and MAY be used as service identifiers
upon successful registration. Because registering a port number
for a specific application consumes a fraction of the shared
resource that is the port number registry, IANA will require the
requester to document the intended use of the port number. This
documentation will be input to the "Expert Review" allocation
procedure [RFC5226], by which IANA will have a technical expert
review the request to determine whether to grant the registration.
The submitted documentation MUST explain why using a port number
in the Dynamic Ports range is unsuitable for the given
application. Ports in the User Ports range may also be assigned
under the "IETF Review" or "IESG Approval" allocation procedures
[RFC5226], which is how most assignments for IETF protocols are
handled.
o Ports in the System Ports range (0-1023) are also available for
registration through IANA. Because the System Ports range is both
the smallest and the most densely allocated, the requirements for
new allocations are more strict than those for the User Ports
range, and will only be granted under the "IETF Review" or "IESG
Approval" allocation procedures [RFC5226]. A request for a System
Port number MUST document *both* why using a port number from the
User Ports is unsuitable *and* why using a port number from the
Dynamic Ports ranges is unsuitable for that application.
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8.2. Service Name and Port Number De-Registration
The Registrant of a granted port number assignment can return the
port number to IANA at any time if they no longer have a need for it.
The port number will be de-registered and will be marked as Reserved.
IANA should not re-assign port numbers that have been de-registered
until all unassigned port numbers in the specific range have been
assigned.
Before proceeding with a port number de-registration, IANA needs to
reasonably establish that the value is actually no longer in 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. Under this policy, it
will appear in the registry as if it had been created through a
service name registration request that did not include any port
numbers.
On rare occasions, it may still be useful to de-register a service
name. In such cases, IANA will mark the service name as Reserved.
IANA will involve their IESG-appointed expert in such cases.
IANA will include a comment in the registry when de-registration
happens to indicate its historic usage.
8.3. Service Name and Port Number Re-Use
If the Registrant of a granted port number assignment no longer have
a need for the assigned number, but would like to re-use it for a
different application, they can submit a request to IANA to do so.
Logically, port number re-use is to be thought of as a de-
registration (Section 8.2) followed by an immediate re-registration
(Section 8.1) 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.
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
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application is NOT RECOMMENDED.
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.
8.4. Service Name and Port Number Revocation
A port number revocation can be thought of as an IANA-initiated de-
registration (Section 8.2), and has exactly the same effect on the
registry.
Sometimes, it will be clear that a specific port number is no longer
in use and that IANA can revoke it and mark it as Reserved. At other
times, it may be unclear whether a given assigned port number is
still in use somewhere in the Internet. In those cases, IANA must
carefully consider the consequences of revoking the port number, and
SHOULD only do so if there is an overwhelming need.
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.
Because there is much less danger of exhausting the service name
space compared to the port number space, revoking service names is
NOT RECOMMENDED.
8.5. Service Name and Port Number Transfers
The value of service names and port numbers is defined by their
careful management as a shared Internet resource, whereas enabling
transfer allows the potential for associated monetary exchanges. As
a result, the IETF does not permit service name or port number
assignments to be transferred between parties, even when they are
mutually consenting.
The appropriate alternate procedure is a coordinated de-registration
and registration: The new party requests the service name or port
number via a registration and the previous party releases its
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assignment via the de-registration procedure outlined above.
With the help of their IESG-appointed Expert Reviewer, IANA SHALL
carefully determine if there is a valid technical, operational or
managerial reason to grant the requested new assignment.
8.6. Maintenance Issues
In addition to the formal procedures described above, updates to the
Description and Contact information are coordinated by IANA in an
informal manner, and may be initiated by either the registrant or by
IANA, e.g., by the latter requesting an update to current contact
information. (Note that Registrant cannot be changed; see
Section 8.5 above.)
8.7. Disagreements
In the case of disagreements around any request there is the
possibility of appeal following the normal appelas process for IANA
registrations as defined by Section 7 of "Guidelines for Writing an
IANA Considerations Section in RFCs" [RFC5226].
9. Security Considerations
The IANA guidelines described in this document do not change the
security properties of UDP, TCP, SCTP, or DCCP.
Assignment of a service name or port number does not in any way imply
an endorsement of an application or product, and the fact that
network traffic is flowing to or from an assigned port number does
not mean that it is "good" traffic, or even that it is used by the
assigned service. Firewall and system administrators should choose
how to configure their systems based on their knowledge of the
traffic in question, not based on whether or not there is an assigned
service name or port number.
Services are expected to include support for security, either as
default or dynamically negotiated in-band. The use of separate
service name or port number assignments for secure and insecure
variants of the same service is to be avoided in order to discourage
the deployment of insecure services.
10. IANA Considerations
This document obsoletes Sections 8 and 9.1 of the March 2000 IANA
Allocation Guidelines [RFC2780].
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Upon approval of this document, IANA is requested to contact Stuart
Cheshire, maintainer of the independent service name registry
[SRVREG], in order to merge the contents of that private registry
into the official IANA registry. It is expected that the independent
registry web page will be updated with pointers to the IANA registry
and to this RFC.
IANA is instructed to create a new service name entry in the service
name and port number registry [PORTREG] for any entry in the
"Protocol and Service Names" registry [PROTSERVREG] that does not
already have one assigned.
IANA is also instructed to indicate in the Assignment Notes for "www"
and "www-http" that they are duplicate terms that refer to the "http"
service, and should not be used for discovery purposes. For this
conceptual service (human-readable web pages served over HTTP) the
correct service name to use for service discovery purposes is "http"
(see Section 5).
10.1. Service Name Consistency
Section 8.1 defines which character strings are well-formed service
names, which until now had not been clearly defined. The definition
in Section 8.1 was chosen to allow maximum compatibility of service
names with current and future service discovery mechanisms.
As of August 5, 2009 approximately 98% of the so-called "Short Names"
from existing port number registrations [PORTREG] meet the rules for
legal service names stated in Section 8.1, and hence for these
services their service name will be exactly the same as their "Short
Name".
The remaining approximately 2% of the exiting "Short Names" are not
suitable to be used directly as well-formed service names because
they contain illegal characters such as asterisks, dots, pluses,
slashes, or underscores. All existing "Short Names" conform to the
length requirement of 15 characters or fewer. For these unsuitable
"Short Names", listed in the table below, the service name will be
the Short Name with any illegal characters replaced by hyphens. IANA
SHALL add an entry to the registry giving the new well-formed primary
service name for the existing service, that otherwise duplicates the
original assignment information. In the description field of this
new entry giving the primary service name, IANA SHALL record that it
assigns a well-formed service name for the previous service and
reference the original assignment. In the Assignment Notes field of
the original assignment, IANA SHALL add a note that this entry is an
alias to the new well-formed service name, and that the old service
name is historic, not usable for use with many common service
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discovery mechanisms.
Names containing illegal characters to be replaced by hyphens:
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+----------------+-----------------+-----------------+
| 914c/g | 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 |
| EtherNet/IP-1 | EtherNet/IP-2 | 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 | LiebDevMgmt_A | LiebDevMgmt_C |
| LiebDevMgmt_DM | 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 | sql*net | srvc_registry |
| stm_pproc | subntbcst_tftp | udt_os |
| universe_suite | veritas_pbx | vision_elmd |
| vision_server | wrs_registry | z39.50 |
+----------------+-----------------+-----------------+
Following the example set by the "application/whoispp-query" MIME
Content-Type [RFC2957], the service name for "whois++" will be
"whoispp".
10.2. Port Numbers for SCTP and DCCP Experimentation
Two System UDP and TCP ports, 1021 and 1022, have been reserved for
experimental use [RFC4727]. This document assigns the same port
numbers for SCTP and DCCP, updates the TCP and UDP registrations, and
also instructs IANA to automatically assign these two port numbers
for any future transport protocol with a similar 16-bit port number
namespace.
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Note that these port numbers are meant for temporary experimentation
and development in controlled environments. Before using these port
numbers, carefully consider the advice in Section 6.1 in this
document, as well as in Sections 1 and 1.1 of "Assigning Experimental
and Testing Numbers Considered Useful" [RFC3692]. Most importantly,
application developers must request a permanent port number
assignment from IANA as described in Section 8.1 before any kind of
non-experimental deployment.
+--------------------+----------------------------+
| Registrant | IETF <iesg@ietf.org> |
| Contact | IESG <iesg@ietf.org> |
| Service Name | exp1 |
| Port Number | 1021 |
| Transport Protocol | DCCP, SCTP, TCP, UDP |
| Description | RFC3692-style Experiment 1 |
| Reference | [RFCyyyy],RFC 4727] |
+--------------------+----------------------------+
+--------------------+----------------------------+
| Registrant | IETF <iesg@ietf.org> |
| Contact | IESG <iesg@ietf.org> |
| Service Name | exp2 |
| Port Number | 1022 |
| Transport Protocol | DCCP, SCTP, TCP, UDP |
| Description | RFC3692-style Experiment 2 |
| Reference | [RFCyyyy], [RFC4727] |
+--------------------+----------------------------+
[RFC Editor Note: Please change "yyyy" to the RFC number allocated to
this document before publication.]
10.3. Updates to DCCP Registries
This document updates the IANA allocation procedures for the DCCP
Port Number and DCCP Service Codes Registries [RFC4340].
10.3.1. DCCP Service Code Registry
Service Codes are allocated first-come-first-served according to
Section 19.8 of the DCCP specification [RFC4340]. This document
updates that section by extending the guidelines given there in the
following ways:
o IANA MAY assign new Service Codes without seeking Expert Review
using their discretion, but SHOULD seek expert review if a request
seeks more than five Service Codes.
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o 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 [RFC4340].
10.3.2. DCCP Port Numbers Registry
The DCCP ports registry is defined by Section 19.9 of the DCCP
specification [RFC4340]. Allocations in this registry require prior
allocation of a Service Code. Not all Service Codes require IANA-
assigned ports. This document updates that section by extending the
guidelines given there in the following way:
o 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 System Ports range (0 through 1023), require an
"IETF Review" [RFC5226] prior to allocation by IANA [RFC4340].
o IANA MUST NOT allocate more than one DCCP server port to a single
service code value.
o The allocation of multiple service codes to the same DCCP port is
allowed, but subject to expert review.
o The set of Service Code values associated with a DCCP server port
should be recorded in the service name and port number registry.
o 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.
The DCCP specification [RFC4340] notes that a short port name MUST be
associated with each DCCP server port that has been assigned. This
document clarifies that this short port name is the Service Name as
defined here, and this name MUST be unique.
11. Contributors
Alfred Hoenes (ah@tr-sys.de) and Allison Mankin (mankin@psg.com) have
contributed text and ideas to this document.
12. Acknowledgments
The text in Section 10.3 is based on a suggestion originally proposed
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as a part of the DCCP Service Codes document[RFC5595] by Gorry
Fairhurst.
Lars Eggert is partly funded by the Trilogy Project [TRILOGY], a
research project supported by the European Commission under its
Seventh Framework Program.
13. References
13.1. 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.
Cotton, et al. Expires April 28, 2011 [Page 28]
Internet-Draft Service Name and Port Number Procedures October 2010
[RFC5234] Crocker, D. and P. Overell, "Augmented BNF for Syntax
Specifications: ABNF", STD 68, RFC 5234, January 2008.
13.2. Informative References
[I-D.cheshire-dnsext-dns-sd]
Cheshire, S. and M. Krochmal, "DNS-Based Service
Discovery", draft-cheshire-dnsext-dns-sd-06 (work in
progress), March 2010.
[I-D.cheshire-nat-pmp]
Cheshire, S., "NAT Port Mapping Protocol (NAT-PMP)",
draft-cheshire-nat-pmp-03 (work in progress), April 2008.
[IGD] UPnP Forum, "Internet Gateway Device (IGD) V 1.0",
November 2001.
[PORTREG] Internet Assigned Numbers Authority (IANA), "Service Name
and Transport Protocol Port Number Registry",
http://www.iana.org/assignments/port-numbers.
[PROTSERVREG]
Internet Assigned Numbers Authority (IANA), "Protocol and
Service Names Registry",
http://www.iana.org/assignments/service-names.
[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.
[RFC1700] Reynolds, J. and J. Postel, "Assigned Numbers", RFC 1700,
October 1994.
[RFC2782] Gulbrandsen, A., Vixie, P., and L. Esibov, "A DNS RR for
specifying the location of services (DNS SRV)", RFC 2782,
February 2000.
[RFC2957] Daigle, L. and P. Faltstrom, "The application/
whoispp-query Content-Type", RFC 2957, October 2000.
[RFC3232] Reynolds, J., "Assigned Numbers: RFC 1700 is Replaced by
an On-line Database", RFC 3232, January 2002.
[RFC3692] Narten, T., "Assigning Experimental and Testing Numbers
Considered Useful", BCP 82, RFC 3692, January 2004.
Cotton, et al. Expires April 28, 2011 [Page 29]
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[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.
[RFC5389] Rosenberg, J., Mahy, R., Matthews, P., and D. Wing,
"Session Traversal Utilities for NAT (STUN)", RFC 5389,
October 2008.
[RFC5595] Fairhurst, G., "The Datagram Congestion Control Protocol
(DCCP) Service Codes", RFC 5595, September 2009.
[RFC5766] Mahy, R., Matthews, P., and J. Rosenberg, "Traversal Using
Relays around NAT (TURN): Relay Extensions to Session
Traversal Utilities for NAT (STUN)", RFC 5766, April 2010.
[SRVREG] "DNS SRV Service Types Registry",
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
Michelle Cotton
Internet Corporation for Assigned Names and Numbers
4676 Admiralty Way, Suite 330
Marina del Rey, CA 90292
USA
Phone: +1 310 823 9358
Email: michelle.cotton@icann.org
URI: http://www.iana.org/
Cotton, et al. Expires April 28, 2011 [Page 30]
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Lars Eggert
Nokia Research Center
P.O. Box 407
Nokia Group 00045
Finland
Phone: +358 50 48 24461
Email: lars.eggert@nokia.com
URI: http://research.nokia.com/people/lars_eggert/
Joe Touch
USC/ISI
4676 Admiralty Way
Marina del Rey, CA 90292
USA
Phone: +1 310 448 9151
Email: touch@isi.edu
URI: http://www.isi.edu/touch
Magnus Westerlund
Ericsson
Farogatan 6
Stockholm 164 80
Sweden
Phone: +46 8 719 0000
Email: magnus.westerlund@ericsson.com
Stuart Cheshire
Apple Inc.
1 Infinite Loop
Cupertino, CA 95014
USA
Phone: +1 408 974 3207
Email: cheshire@apple.com
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