Diameter Applications Design Guidelines
draft-ietf-dime-app-design-guide-14
The information below is for an old version of the document.
| Document | Type |
This is an older version of an Internet-Draft that was ultimately published as RFC 7423.
|
|
|---|---|---|---|
| Authors | Lionel Morand , Victor Fajardo , Hannes Tschofenig | ||
| Last updated | 2012-04-01 | ||
| Replaces | draft-fajardo-dime-app-design-guide | ||
| RFC stream | Internet Engineering Task Force (IETF) | ||
| Formats | |||
| Reviews | |||
| Additional resources | Mailing list discussion | ||
| Stream | WG state | WG Document | |
| Document shepherd | (None) | ||
| IESG | IESG state | Became RFC 7423 (Best Current Practice) | |
| Consensus boilerplate | Unknown | ||
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| Send notices to | (None) |
draft-ietf-dime-app-design-guide-14
Diameter Maintenance and Extensions L. Morand, Ed.
(DIME) Orange Labs
Internet-Draft V. Fajardo
Intended status: Informational
Expires: October 3, 2012 H. Tschofenig
Nokia Siemens Networks
April 1, 2012
Diameter Applications Design Guidelines
draft-ietf-dime-app-design-guide-14
Abstract
The Diameter Base protocol provides facilities for protocol
extensibility enabling to define new Diameter applications or modify
existing applications. This document is a companion document to the
Diameter Base protocol that further explains and clarifies the rules
to extend the Diameter Base protocol. It is meant as a guidelines
document and therefore it does not add, remove or change existing
rules.
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Requirements Language
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 [RFC2119].
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 October 3, 2012.
Copyright Notice
Copyright (c) 2012 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.
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 4
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 5
3. Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
4. Reusing existing Diameter applications . . . . . . . . . . . . 8
4.1. Adding a new command . . . . . . . . . . . . . . . . . . . 8
4.2. Deleting a command . . . . . . . . . . . . . . . . . . . . 9
4.3. Reusing existing commands . . . . . . . . . . . . . . . . 9
4.3.1. Adding AVPs to a command . . . . . . . . . . . . . . . 10
4.3.2. Deleting AVPs from a Command . . . . . . . . . . . . . 11
4.4. Reusing existing AVPs . . . . . . . . . . . . . . . . . . 12
4.4.1. Setting of the AVP flags . . . . . . . . . . . . . . . 12
4.4.2. Reuse of AVP of type Enumerated . . . . . . . . . . . 12
5. Rules for new Applications . . . . . . . . . . . . . . . . . . 13
5.1. Use of Application-Id in a Message . . . . . . . . . . . . 13
5.2. Application Specific Session State Machine . . . . . . . . 14
6. End-to-End Applications Capabilities Exchange . . . . . . . . 15
7. Diameter Accounting Support . . . . . . . . . . . . . . . . . 16
8. Generic Diameter Extensions . . . . . . . . . . . . . . . . . 18
9. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 20
10. Security Considerations . . . . . . . . . . . . . . . . . . . 21
11. Contributors . . . . . . . . . . . . . . . . . . . . . . . . . 22
12. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 23
13. References . . . . . . . . . . . . . . . . . . . . . . . . . . 24
13.1. Normative References . . . . . . . . . . . . . . . . . . . 24
13.2. Informative References . . . . . . . . . . . . . . . . . . 24
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 26
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1. Introduction
The Diameter Base protocol provides facilities to extend the Diameter
Base protocol (see Section 1.3 of [I-D.ietf-dime-rfc3588bis]) for
supporting new functionalities. In the context of this document,
extending Diameter means one of the following:
1. Addition of a new functionality to an existing Diameter
application without defining a new application.
2. Addition of a new functionality to an existing Diameter
application that requires the definition of a new application.
3. The definition of a new Diameter application to provide a set of
functionalities not supporting by existing applications.
4. The definition of a new generic functionality that can be reused
across different applications.
All of these choices are design decisions that can done by any
combination of reusing existing or defining new commands, AVPs or AVP
values. Protocol designers do, however, not have total freedom when
making their design. A number of rules defined in
[I-D.ietf-dime-rfc3588bis] place constraints on when an extension
demands a new Diameter application to be defined or a new command
code to be registered. The objective of this document is the
following:
o Clarify updated Diameter extensibility rules in the Diameter Base
Protocol.
o Clarify usage of certain Diameter functionalities that are not
explicitly described in the Diameter Base specification.
o Discuss design choices and provide guidelines when defining
applications.
o Present tradeoffs of design choices.
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2. Terminology
This document reuses the terminology used in
[I-D.ietf-dime-rfc3588bis].
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3. Overview
As designed, the Diameter Base protocol can be seen as a two-layer
protocol. The lower layer is mainly responsible for managing
connections between neighboring peers and for message routing. The
upper layer is where the Diameter applications reside. This model is
in line with a Diameter node having an application layer and a peer-
to-peer delivery layer. The Diameter Base protocol document
completely defines the architecture and behavior of the message
delivery layer and then provides the framework for designing Diameter
applications on the application layer. This framework includes
definitions of application sessions and accounting support (see
Section 8 and 9 of [I-D.ietf-dime-rfc3588bis]). The remainder of
this document also treats a Diameter node as a single instance of a
Diameter message delivery layer and one or more Diameter applications
using it.
The Diameter protocol is designed to be extensible and the principles
are descibed in the section 1.3 of [I-D.ietf-dime-rfc3588bis].
Extending Diameter can mean the definition of a new Diameter
application and/or the reuse of commands, AVPs and AVP values in any
combination for the purpose of inheriting the features of an existing
Diameter application. The reuse recommendation is meaningful as most
of the requirements defined for a new application are likely already
fulfilled by an existing application.
However, when reusing existing applications, there is a greater
likelihood of ambiguity on how much of the existing application can
be enhanced without being distorted too much and therefore requiring
the definition of a new application.
The impacts of extending existing applications can be categorized as
follow:
Minor Extension: Enhancing the functional scope of an existing
application by the addition of optional features to support. Such
enhancement has no backward compatibility issue with the existing
application. A typical example would be the definition of a new
optional AVP to use in an existing command. In general, this
includes everything that is not covered by the next category. The
standardization effort will be fairly small.
Major Extension: Enhancing the functional scope of an existing
application in such a way that this implies backward compatible
change to the existing application and then requires the
definition of a new Diameter application. A typical example would
be the creation of a new command for providing functionality not
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supported by existing applications. For such extension, a
significant specification effort is required and a carefull
approach is recommended.
The rules outlined in the section 1.3 of [I-D.ietf-dime-rfc3588bis]
indicate when an extension requires a new command code to be
registered and when new Diameter applications have to be defined.
The subsequent sections further explain and clarify the rules to
extend the Diameter Base protocol. It is meant as a guidelines
document and therefore it does not add, remove or change existing
rules.
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4. Reusing existing Diameter applications
When selecting the Diameter Base protocol to support new
functionalities, protocol designers are advised to try to re-use as
much as possible existing Diameter applications to simplify
standardization, implementation and avoid potential interoperability
issues. However, existing application needs to be adapted to support
new requirements and these modifications can be at the command level
and/or at the AVP level. The following sections describe the
possible modifications that can be performed on existing applications
and their related impacts.
4.1. Adding a new command
Adding a new command is considered as a major extension and requires
a new Diameter application to be defined. Adding a new command to an
application means either defining a completely new command or
importing the command's CCF syntax specification from another
application whereby the new application inherits some or all of the
functionality of the application where the command came from. In the
former case, the decision to create an new application is
straightforward since this is typically a result of adding a new
functionality that does not exist yet. For the latter, the decision
to create a new application will depend on whether importing the
command in a new application is more suitable than simply using the
existing application as it is in conjunction with any other
application. Therefore, a case by case study of each application
requirement should be applied.
An illustrative example is the command pair defined in Diameter EAP
application [RFC4072] that can be re-used conjointly with any other
application (e.g. the Diameter NASREQ application [RFC4005]) as soon
as standard EAP-based authentication procedures need to be supported
by the implementation. It may therefore not be required to import
the command pair in the new defined application.
However, in general, it is difficult to come to a hard guideline, and
so a case by case study of each application requirement should be
applied. Before adding or importing a command, application designers
should consider the following:
o Can the new functionality be fulfilled by creating a new command
independent from any existing command? In this case, the
resulting new application and the existing application can work
independent of, but cooperating with each other.
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o Can the existing command be reused without major extensions and
therefore without the need for the definition of a new
application, e.g. new funtionality introduced by the creation of
new optional AVPs.
o Care should be taken to avoid a liberal method of importing
existing command's CCF syntax specification. This would result in
a monolithic and hard to manage applications supporting too many
different functionalities and can cause interoperability issues
between the different applications. .
4.2. Deleting a command
Although this process is not typical, removing a command to an
application requires a new Diameter application to be defined. this
is due to the fact that the reception of the deleted command would
systematically result in a protocol error
(DIAMETER_COMMAND_UNSUPPORTED).
It is unusual to delete an existing command from an application for
the sake of deleting it or the functionality it represents. This
normally indicates of a flawed design. An exception might be if the
intent of the deletion is to create a newer version of the same
application which is somehow simpler than the previous version.
4.3. Reusing existing commands
This section discusses rules in adding and/or deleting AVPs from an
existing command of an existing application. The cases described in
this section may not necessarily result in the creation of new
applications.
It is worth to note that the strong recommendation to re-use existing
commands in the [RFC3588] was to prevent rapid scarcity of code
values available for vendor-specific commands.
[I-D.ietf-dime-rfc3588bis] relaxes the policy with respect to the
allocation of command codes for vendor-specific uses and enlarges the
range of available code values for vendor-specific applications.
Therefore, if it is still recommended to re-use as much as possible
existing commands, protocol designers can consider more easily the
definition of a new command when it is a solution more suitable than
twisting existings command use and applications.
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4.3.1. Adding AVPs to a command
Based on the rules in [I-D.ietf-dime-rfc3588bis], AVPs that are added
to an existing command can be categorized into:
o Mandatory (to understand) AVPs. As defined in
[I-D.ietf-dime-rfc3588bis], these are AVPs with the M-bit flag
set, which means that a Diameter node receiving are required to
understand not only their values but their semantics. Failure to
do so will cause an message handling error. This is regardless of
whether these AVPs are required or optional as specified by the
command's CCF syntax specification.
o Optional (to understand) AVPs. As defined in
[I-D.ietf-dime-rfc3588bis], these are AVPs with the M-bit flag
cleared, which mean that a Diameter node receiving these AVP can
simply ignore them if not supported in the process of the received
command.
The rules are strict in the case where the AVPs to be added are
mandatory to understand i.e. with the M-bit set. A mandatory AVP
cannot be added to an existing command without defining a new
Diameter application, as stated in [I-D.ietf-dime-rfc3588bis]. This
falls into the "Major Extensions" category. Despite the clarity of
the rule, ambiguity still arises when evaluating whether a new AVP
being added should be mandatory to begin with. Here is a list of few
common questions that application designers should wonder when trying
to decide:
o Would it be required for the receiving side to be able to process
and understand the AVP and its content?
o Would the new AVPs change the state machine of the application?
o Would the presence of the new AVP lead to a different number of
roundtrips, effectively changing the state machine of the
application?
o Would the new AVP be used to differentiate between old and new
versions of the same application whereby the two versions are not
backward compatible?
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o Would the new AVP have duality in meaning i.e. be used to carry
application related information as well as be used to indicate
that the message is for a new application?
When one of the above questions can be answered in the affirmative
then the M-bit has to be set for the new AVP.
If application designers are instead contemplating on the use of
optional AVPs i.e. with the M-bit cleared, then the following are
some of the pitfalls that should be avoided:
o Use of optional AVPs with intersecting meaning. One AVP has
partially the same usage and meaning as another AVP. The presence
of both can lead to confusion.
o An optional AVPs with dual purpose, i.e. to carry applications
data as well as to indicate support for one or more features.
This has a tendency to introduce interpretation issues.
o Adding one or more optional AVPs and indicating (usually within
descriptive text for the command) that at least one of them has to
be present in the command. This essentially circumventing the
ABNF and is equivalent to adding a mandatory AVPs to the command.
These practices generally result in interoperability issues and
should be avoided as much as possible.
4.3.2. Deleting AVPs from a Command
When deleting an AVP from a command, the following cases need to be
differentiated:
o Deleting an AVP that is indicated as { AVP } in the command's CCF
syntax specification, whatever the setting of the M-bit set. This
means the definition of a new command. In this case, a new
command code and subsequently a new Diameter application have to
be specified.
o Deleting an AVP with M-bit set that is indicated as [ AVP ] in the
command's CCF syntax specification. No new command code has to be
specified but the definition of a new Diameter application is
required.
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o Deleting an AVP with the M-bit cleared that is indicated as [ AVP
] in the command's CCF syntax specification. In this case, the
AVP can be deleted without consequences.
If possible application designers should attempt the reuse the
command's CCF syntax specification without modification and simply
ignore (but not delete) any optional AVP that will not be used. This
is to maintain compatibility with existing applications that will not
know about the new functionality as well as maintain the integrity of
existing dictionaries.
4.4. Reusing existing AVPs
This section discusses rules in reusing existing AVP when reusing an
existing command or defining a new command in a new application.
4.4.1. Setting of the AVP flags
When reusing AVPs in a new application, the AVP flag setting, such as
the mandatory flag ('M'-bit), has to be re-evaluated for a new
Diameter application and, if necessary, even for every command within
the application. In general, for AVPs defined outside of the base
protocol, its mandatory characteristics are tied to its role within
an application and command.
All other AVP flags shall remain unchanged
4.4.2. Reuse of AVP of type Enumerated
When modifying the set of values supported by an AVP of type
Enumerated, this means defining a new AVP. Modifying the set of
Enumerated values includes adding a value or deprecating the use of a
value defined initially for the AVP. Defining a new AVP will avoid
interoperability issues.
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5. Rules for new Applications
The general recommendation for Diameter extensibility is to reuse
commands, AVPs and AVP values as much as possible. However, some of
the extensibility rules described in the previous section also apply
to scenarios where a designer is trying to define a completely new
Diameter application.
This section discusses the case where new applications have
requirements that cannot be filled by existing applications and would
require definition of completely new commands, AVPs and/or AVP
values. Typically, there is little ambiguity about the decision to
create these types of applications. Some examples are the interfaces
defined for the IP Multimedia Subsystem of 3GPP, i.e. Cx/Dx
([TS29.228] and [TS29.229]), Sh ([TS29.328] and [TS29.329]) etc.
Application designers should also follow the theme of Diameter
extensibility which in this case means to import existing AVPs and
AVP values for any newly defined commands. In certain cases where
accounting will be used, the models described in Section 7 should
also be considered. Though some decisions may be clear, designers
should also consider certain aspects of defining a new application.
Some of these aspects are described in following sections.
5.1. Use of Application-Id in a Message
When designing new applications, designers should specify that the
application ID carried in all session level messages must be the
application ID of the application using those messages. This
includes the session level messages defined in base protocol, i.e.,
RAR/RAA, STR/STA, ASR/ASA and possibly ACR/ACA in the coupled
accounting model, see Section 7. Existing specifications may not
adhere to this rule for historical or other reasons. However, this
scheme should be followed to avoid possible routing problems for
these messages.
In general, when a new application has been allocated with a new
application id and it also reuses existing commands with or without
modifications (Sec 4.1), it must use the newly allocated application
id in the header and in all relevant application id AVPs (Auth-
Application-Id or Acct-Application-Id) present in the commands
message body.
Additionally, application designs using
Vendor-Specific-Application-Id AVP should not use the Vendor-Id AVP
to further dissect or differentiate the vendor-specification
application id. Diameter routing is not based on the Vendor-Id. As
such, the Vendor-ID should not be used as an additional input for
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routing or delivery of messages. In general, the Vendor-Id AVP is an
informational AVP only and kept for backward compatibility reasons.
5.2. Application Specific Session State Machine
Section 8 of [I-D.ietf-dime-rfc3588bis] provides session state
machines for authentication, authorization and accounting (AAA)
services. When a new application is being defined that cannot
clearly be categorized into any of these services it is recommended
that the application itself define its own session state machine.
The existing session state machines defined by
[I-D.ietf-dime-rfc3588bis] is not intended for general use beyond AAA
services, therefore any behavior not covered by that category would
not fit well. Support for server initiated request is a clear
example where an application specific session state machine would be
needed, for example, the Rw interface for ITU-T push model (
cf.[Q.3303.3]).
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6. End-to-End Applications Capabilities Exchange
It is also possible that applications can use optional AVPs to
exchange application specific capabilities and features. These AVPs
are exchanged on an end-to-end basis. Examples of this can be found
in [I-D.ietf-dime-mip6-integrated] and
[I-D.ietf-dime-qos-attributes].
The end-to-end capabilities AVPs can aid in the following cases:
o Formalizing the way new functionality is added to existing
applications by announcing support for it.
o Applications that do not understand these AVP can discard it upon
receipt. In such case, senders of the AVP can also safely assume
the receiving end-point does not support any functionality carried
by the AVP if it is not present in subsequent responses.
o Useful in cases where deployment choices are offered and the
generic design can be made available for a number of applications.
Note that this list is not meant to be comprehensive.
When used in a new application, protocol designers should clearly
specify this end-to-end capabilities exchange and the corresponding
behaviour of the Diameter nodes supporting the application.
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7. Diameter Accounting Support
Accounting can be treated as an auxiliary application which is used
in support of other applications. In most cases, accounting support
is required when defining new applications. This document provides
two(2) possible models for using accounting:
Split Accounting Model
In this model, the accounting messages will use the Diameter base
accounting application ID (value of 3). The design implication
for this is that the accounting is treated as an independent
application, especially during Diameter routing. This means that
accounting commands emanating from an application may be routed
separately from the rest of the other application messages. This
may also imply that the messages generally end up in a central
accounting server. A split accounting model is a good design
choice when:
* The application itself will not define its own unique
accounting commands.
* The overall system architecture permits the use of centralized
accounting for one or more Diameter applications.
Centralizing accounting may have advantages but there are also
drawbacks. The model assumes that the accounting server can
somehow differentiate received accounting messages. Since the
received accounting messages can be for any application and/or
service, the accounting server has to be have a method to uniquely
match accounting messages with applications and/or services being
accounted for. This may mean defining new AVPs, checking the
presence, absence or contents of existing AVPs or checking the
contents of the accounting records itself. But in general, there
is no clean and generic scheme for sorting these messages.
Therefore, the use of this model is recommended only when all
received accounting messages can be clearly identified and sorted.
For most cases, the use of Coupled Accounting Model is
recommended.
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Coupled Accounting Model
In this model, the accounting messages will use the application ID
of the application using the accounting service. The design
implication for this is that the accounting messages are tightly
coupled with the application itself; meaning that accounting
messages will be routed like any other application messages. It
would then be the responsibility of the application server
(application entity receiving the ACR message) to send the
accounting records carried by the accounting messages to the
proper accounting server. The application server is also
responsible for formulating a proper response (ACA). A coupled
accounting model is a good design choice when:
* The system architecture or deployment will not provide an
accounting server that supports Diameter.
* The system architecture or deployment requires that the
accounting service for the specific application should be
handled by the application itself.
* The application server is provisioned to use a different
protocol to access the accounting server; e.g., via LDAP, SOAP
etc. This includes attempting to support older accounting
systems that are not Diameter aware.
In all cases above, there will generally be no direct Diameter
access to the accounting server.
These models provide a basis for using accounting messages.
Application designers may obviously deviate from these models
provided that the factors being addressed here have also been taken
into account. Though it is not recommended, examples of other
methods might be defining a new set of commands to carry application
specific accounting records.
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8. Generic Diameter Extensions
Generic Diameter extensions are AVPs, commands or applications that
are designed to support other Diameter applications. They are
auxiliary applications meant to improve or enhance the Diameter
protocol itself or Diameter applications/functionality. Some
examples include the extensions to support auditing and redundancy
(see [I-D.calhoun-diameter-res-mgmt]), improvements in duplicate
detection scheme (see [I-D.asveren-dime-dupcons]), and piggybacking
of QoS attributes (see [I-D.ietf-dime-qos-attributes]).
Since generic extensions can cover many aspects of Diameter and
Diameter applications, it is not possible to enumerate all the
probable scenarios in this document. However, some of the most
common considerations are as follows:
o Backward compatibility: Dealing with existing applications that do
not understand the new extension. Designers also have to make
sure that new extensions do not break expected message delivery
layer behavior.
o Forward compatibility: Making sure that the design will not
introduce undue restrictions for future applications. Future
applications attempting to support this feature should not have to
go through great lengths to implement any new extensions.
o Tradeoffs in signaling: Designers may have to choose between the
use of optional AVPs piggybacked onto existing commands versus
defining new commands and applications. Optional AVPs are simpler
to implement and may not need changes to existing applications;
However, the drawback is that the timing of sending extension data
will be tied to when the application would be sending a message.
This has consequences if the application and the extensions have
different timing requirements. The use of commands and
applications solves this issue but the tradeoff is the additional
complexity of defining and deploying a new application. It is
left up to the designer to find a good balance among these
tradeoffs based on the requirements of the extension.
In practice, it is often the case that the generic extensions use
optional AVPs because it's simple and not intrusive to the
application that would carry it. Peers that do not support the
generic extensions need not understand nor recognize these optional
AVPs. However, it is recommended that the authors of the extension
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specify the context or usage of the optional AVPs. As an example, in
the case that the AVP can be used only by a specific set of
applications then the specification must enumerate these applications
and the scenarios when the optional AVPs will be used. In the case
where the optional AVPs can be carried by any application, it is
should be sufficient to specify such a use case and perhaps provide
specific examples of applications using them.
In most cases, these optional AVPs piggybacked by applications would
be defined as a Grouped AVP and it would encapsulate all the
functionality of the generic extension. In practice, it is not
uncommon that the Grouped AVP will encapsulate an existing AVP that
has previously been defined as mandatory ('M'-bit set) e.g., 3GPP IMS
Cx / Dx interfaces ([TS29.228] and [TS29.229]).
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9. IANA Considerations
This document does not require actions by IANA.
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10. Security Considerations
This document does provides guidelines and considerations for
extending Diameter and Diameter applications. It does not define nor
address security related protocols or schemes.
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11. Contributors
The content of this document was influenced by a design team created
to revisit the Diameter extensibility rules. The team consisting of
the members listed below was formed in February 2008 and finished its
work in June 2008.
o Avi Lior
o Glen Zorn
o Jari Arkko
o Lionel Morand
o Mark Jones
o Victor Fajardo
o Tolga Asveren
o Jouni Korhonen
o Glenn McGregor
o Hannes Tschofenig
o Dave Frascone
We would like to thank Tolga Asveren, Glenn McGregor, and John
Loughney for their contributions as co-authors to earlier versions of
this document.
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12. Acknowledgments
We greatly appreciate the insight provided by Diameter implementers
who have highlighted the issues and concerns being addressed by this
document.
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13. References
13.1. Normative References
[I-D.ietf-dime-rfc3588bis]
Fajardo, V., Arkko, J., Loughney, J., and G. Zorn,
"Diameter Base Protocol", draft-ietf-dime-rfc3588bis-31
(work in progress), March 2012.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC3588] Calhoun, P., Loughney, J., Guttman, E., Zorn, G., and J.
Arkko, "Diameter Base Protocol", RFC 3588, September 2003.
13.2. Informative References
[I-D.asveren-dime-dupcons]
Asveren, T., "Diameter Duplicate Detection Cons.",
draft-asveren-dime-dupcons-00 (work in progress),
August 2006.
[I-D.calhoun-diameter-res-mgmt]
Calhoun, P., "Diameter Resource Management Extensions",
draft-calhoun-diameter-res-mgmt-08.txt (work in progress),
March 2001.
[I-D.ietf-dime-mip6-integrated]
Korhonen, J., Bournelle, J., Tschofenig, H., Perkins, C.,
and K. Chowdhury, "Diameter Mobile IPv6: Support for
Network Access Server to Diameter Server Interaction",
draft-ietf-dime-mip6-integrated-12 (work in progress),
January 2009.
[I-D.ietf-dime-qos-attributes]
Korhonen, J., Tschofenig, H., Arumaithurai, M., Jones, M.,
and A. Lior, "Traffic Classification and Quality of
Service Attributes for Diameter",
draft-ietf-dime-qos-attributes-15 (work in progress),
December 2009.
[Q.3303.3]
3rd Generation Partnership Project, "ITU-T Recommendation
Q.3303.3, "Resource control protocol no. 3 (rcp3):
Protocol at the Rw interface between the Policy Decision
Physical Entity (PD-PE) and the Policy Enforcement
Physical Entity (PE-PE): Diameter"", 2008.
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[RFC4005] Calhoun, P., Zorn, G., Spence, D., and D. Mitton,
"Diameter Network Access Server Application", August 2005,
<http://www.rfc-editor.org/rfc/rfc4005.txt>.
[RFC4072] Eronen, P., Hiller, T., and G. Zorn, "Diameter Extensible
Authentication Protocol (EAP) Application", August 2005,
<http://www.rfc-editor.org/rfc/rfc4072.txt>.
[TS29.228]
3rd Generation Partnership Project, "3GPP TS 29.228;
Technical Specification Group Core Network and Terminals;
IP Multimedia (IM) Subsystem Cx and Dx Interfaces;
Signalling flows and message contents",
<http://www.3gpp.org/ftp/Specs/html-info/29272.htm>.
[TS29.229]
3rd Generation Partnership Project, "3GPP TS 29.229;
Technical Specification Group Core Network and Terminals;
Cx and Dx interfaces based on the Diameter protocol;
Protocol details",
<http://www.3gpp.org/ftp/Specs/html-info/29229.htm>.
[TS29.328]
3rd Generation Partnership Project, "3GPP TS 29.328;
Technical Specification Group Core Network and Terminals;
IP Multimedia (IM) Subsystem Sh interface; signalling
flows and message content",
<http://www.3gpp.org/ftp/Specs/html-info/29328.htm>.
[TS29.329]
3rd Generation Partnership Project, "3GPP TS 29.329;
Technical Specification Group Core Network and Terminals;
Sh Interface based on the Diameter protocol; Protocol
details",
<http://www.3gpp.org/ftp/Specs/html-info/29329.htm>.
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Authors' Addresses
Lionel Morand (editor)
Orange Labs
Phone: +33 1 4529 6257
Email: lionel.morand@orange.com
Victor Fajardo
Email: vf0213@gmail.com
Hannes Tschofenig
Nokia Siemens Networks
Linnoitustie 6
Espoo 02600
Finland
Phone: +358 (50) 4871445
Email: Hannes.Tschofenig@gmx.net
URI: http://www.tschofenig.priv.at
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