One document matched: draft-ietf-nsis-qspec-00.txt
Network Working Group Jerry Ash
Internet Draft AT&T
<draft-ietf-nsis-qspec-00.txt> Attila Bader
Expiration Date: March 2005 Ericsson
Cornelia Kappler
Siemens AG
September 2004
QoS-NSLP QSpec Template
Status of this Memo
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Copyright (C) The Internet Society (2004). All Rights Reserved.
Ash et al. Expires - March 2005 [Page 1]
Internet Draft QoS-NSLP QSpec Template September 2004
Abstract
This draft describes a QSpec template for the QoS NSIS Signaling
Layer Protocol (QoS NSLP) for signaling QoS reservations in the
Internet. A QSpec is transported in QoS-NSLP messages and is opaque
to QoS NSLP. It contains the QoS Signaling Model (QSM) Control
Information and QoS Description parameters. Control Information is,
for example, the scope of a particular QSpec. QoS Description
parameters are primary input and output parameters of the Resource
Management Function. They include descriptions of the QoS desired
and the QoS reserved. QoS Description parameters can also be used
for collecting information about resource availability along the
path and for signaling a range of acceptable QoS. The QSpec template
defines generic parameters that are common to many QSMs.
Particularly they are derived from the IntServ and DiffServ QoS
Models. They should be used by all QSMs if applicable and must be
understood by all QNEs. By identifying the generic parameters we aim
to ensure interoperability between different QSMs.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . .3
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . . 4
3. Processing of QSpec . . . . . . . . . . . . . . . . . . . . . . 5
4. QSpec Template . . . . . . . . . . . . . . . . . . . . . . . . .6
4.1 Applicability . . . . . . . . . . . . . . . . . . . . . . . . .6
4.2 QSpec Format Overview . . . . . . . . . . . . . . . . . . . . .8
4.2.1 QSM Specific Control Information . . . . . . . . . . . . . . 8
4.2.2 QoS Description . . . . . . . . . . . . . . . . . . . . . . 10
4.2.2.1 QoS Desired . . . . . . . . . . . . . . . . . . . . . . . 11
4.2.2.2 QoS Available . . . . . . . . . . . . . . . . . . . . . . 12
4.2.2.3 QoS Reserved . . . . . . . . . . . . . . . . . . . . . . .12
4.2.2.4 Minimum QoS . . . . . . . . . . . . . . . . . . . . . . . 12
5. Security Considerations . . . . . . . . . . . . . . . . . . . .13
6. Open Issues . . . . . . . . . . . . . . . . . . . . . . . . . .13
7. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 14
8. Intellectual Property Considerations . . . . . . . . . . . . . 14
9. References . . . . . . . . . . . . . . . . . . . . . . . . . . 15
10. Authors' Addresses . . . . . . . . . . . . . . . . . . . . . .16
Appendix A Example Qspecs . . . . . . . . . . . . . . . . . . . . 17
A.1 QSpec for Admission Control for DiffServ . . . . . . . . . . .17
A.2 QSpec for IntServ Controlled Load Service . . . . . . . . . . 18
A.3 QSpec for IntServ Guaranteed Load Service . . . . . . . . . . 18
Appendix B QoS Models, QoS Signaling Models and QSpecs . . . . . .19
Disclaimer of Validity and Copyright Statement . . . . . . . . . .20
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1. Introduction
The QoS NSLP establishes and maintains state at nodes along the path
of a data flow for the purpose of providing forwarding resources
(QoS) for that flow [QoS-SIG]. The design of QoS NSLP is
conceptually similar to RSVP [RSVP], and meets the requirements of
[NSIS-REQ].
QoS NSLP can signal for different QoS Models, i.e. QoS provisioning
methods or QoS architectures. It should be able to support, for
example, IntServ and signaling for DiffServ admission control, and
satisfy the need of more complex control planes such as defined in
[Q.2630, Y.1541]. The usage of QoS NSLP to signal for a specific
QoS Model is called 'QoS Signaling Model'. Examples of different
QSMs for NSIS are specified in [TRQ-QoS-SIG, INTSERV-QoS-SIG, RMD-
QoS-SIG]. For more information on QoS Models and QSMs see the
Appendix.
QSM-specific information is carried in the so-called QSpec object,
which travels in QoS-NSLP messages. The format of the QSpec object
is QSM specific. The QSpec is opaque to QoS NSLP. It contains two
types of information: QSM Control Information and a QoS Description.
The QSM control information contains information not related to the
actual resource management but rather to message processing. An
example of QSM control information is the scope of the QSpec. QSM
Control Information must not be confused with the Common Control
Information, which is a set of objects defined in QoS NSLP. Whereas
QSM Control Information is specific to the QSpec, Common Control
Information is specific to the QoS NSLP message.
The QoS Description can have sub-objects corresponding to the TSpec,
RSpec and AdSpec objects specified in RSVP. This is, the QSpec may
contain a description of QoS desired and QoS reserved. It can also
collect information about available resources. Going beyond RSVP
functionality, the QoS Description also allows indicating a range of
acceptable QoS by defining a sub-object denoting minimum QoS. Usage
of these sub-objects is not bound to particular message types thus
allowing for flexibility. An object collecting information about
available resources may travel in any QoS NSLP message, for example
a QUERY message or a RESERVE message.
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This draft provides a template for QSpec, which is needed in order
to help defining individual QSMs and in order to promote
interoperability between QSMs.
The processing of QSpec is described in more detail in Section 2.
The proposed QSpec template is given in Section 3, including an
applicability statement. Appendix A proposes preliminary QSpecs for
the IntServ Controlled Load and Guaranteed Service QoS Models.
Appendix B explains in more detail the relation between QoS Models,
QSMs and QSpecs. It also explains the current understanding of the
content of a QSM.
2. Terminology
Common NSLP Processing: Functions in a QNE that are related to NSLP
message processing (common for each QoS model)
Generic Parameter: Parameter that MUST be understood by any QNE, and
SHOULD be used if applicable
Immutable Parameter: Parameter that is set by initiating or
responding QNE and is not changed during the processing of QSpec
along the path
Minimum QoS: Minimum QoS is a functionality that MAY be supported by
any QSM: Together with a description of desired QoS, it allows the
QNI to specify a QoS range, i.e. an upper and lower bound. If the
desired QoS is not available, QNFs are going to decrease the
reservation until the minimum QoS is hit.
Mutable Parameter: Parameter that can be changed during the
processing of QSpec by any QNE along the path
Optional Parameter: Parameter that SHOULD be used by QSMs if
applicable
QoS Description: Container of the QSpec sub-objects, which describes
QoS. These parameters are input or output parameters of Resource
Management Function
QoS Available: Parameters describing the available resources. They
are used to collect information along a reservation path.
QoS Desired: The description of the desired QoS and/or the traffic
for which the sender request reservation.
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QoS Model: A methodology to achieve QoS for a traffic flow, e.g.
IntServ Controlled Load.
QoS Reserved: Describes the reserved resources and related QoS
parameters (e.g. Slack Term)
QoS Signaling Model (QSM): A signaling model describing how to use
QoS NSLP to signal for a specific QoS Model
QSM Control Information: Control information that is specific to
QSM, and processed in QSM-specific NSLP Processing.
QSM-specific NSLP Processing: Functions in a QNE that process QSM
Control Information and are specific to each QoS Model.
QSpec: QSpec is the object of QoS-NSLP containing all QoS Model
specific information.
(QSpec) parameter: any parameter appearing in a QSpec, e.g. scope of
QSpec or token bucket.
QSpec sub-object: Main building blocks of QoS Description containing
a parameter set that is input or output of a Resource Management
Function operation.
Resource Management Function: Functions that are related to resource
management, specific to a QoS Model. It processes QoS Description.
3. Processing of QSpec
The model of QoS-NSLP message processing is illustrated in Figure 1.
A QoS-NSLP message is interpreted in the common NSLP processing of a
QNE as described in [QOS-SIG]. The QSpec, however, is opaque to QoS-
NSLP, which means that it is not processed in the common NSLP
processing but handed over to the QSM-specific NSLP processing and
then to the Resource Management Function (RMF). The QSM control
information is interpreted and perhaps modified by the QSM-specific
NSLP processing, and the QoS description is interpreted and may be
modified by the resource management function. Both, QSM-specific
NSLP processing and the RMF, may advise the common NSLP processing
on how to proceed with the signaling, e.g. to tear down a preempted
reservation. From an implementation point of view, the common NSLP
processing is the same in each NSIS capable router, whereas QSM-
specific NSLP processing and the RMF are QSM specific. Note that
the QSM-specific NSLP processing box is an addition to the QoS-NSLP
processing model of [QoS-SIG] suggested in this document.
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+---------------+
| Local |
|Applications or|
|Management (e.g|
|for aggregates)|
+---------------+
^
^
V
+-------------+ +------------+----------+ +---------+
|Common NSLP | |QSM-specific| Resource | | Policy |
| Processing +<<>>>| NSLP |Mgmt. Fct.|<<>| Control |
| | | Processing | | | |
+-------------+ +------------+----------+ +---------+
. ^ | * ^
| V . * ^
+----------+ * ^
| GIMPS | * ^
|Processing| * V
+----------+ * V
| | * V
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
. . * V
| | * .............................
. . * . Traffic Control .
| | * . +---------+.
. . * . |Admission|.
| | * . | Control |.
+----------+ +------------+ . +---------+.
-| Input | | Outgoing |-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.->
| Packet | | Interface | .+----------+ +---------+
=>|Processing|====| Selection |===.| Packet |====| Packet |.=>
| | |(Forwarding)| .|Classifier| Scheduler|.
+----------+ +------------+ .+----------+ +---------+.
Figure 1. Model of QoS-NSLP Processing in a QNE
4. QSpec Template
4.1. Applicability
The QSpec template defines a format for the QSpec, as well as a
number of generic and optional QSpec parameters. Generic parameters
provide a common language for QSM developers to build their QSpecs
and are likely to be re-used in several QSMs.
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This eases comparing different QSpecs and different QSMs - and
possibly simplifies mapping of one into another. Thus developers
should avoid defining parameters similar to the generic,
standardized ones. All parameters used in DiffServ and IntServ QSMs
are generic parameters.
A specific QSM may, however, only use a subset or perhaps none of
the generic QSpec parameters. For instance, it may only allow the
token bucket to be specified. Furthermore, a QSM may define
additional parameters.
All QNEs must be able to understand the generic parameters. It is
important to note this does not imply they must also implement all
generic parameters (e.g. token bucket). However they must be able to
provide a meaningful mapping to locally used parameters.
Hence, to summarize, generic parameters SHOULD be used by QSMs if
applicable. Generic parameters MUST be understood by any QNE. QNEs
do not need to implement generic parameters. They MUST however be
able to provide a meaningful mapping from generic parameters onto
local parameters. If they translate generic parameters into local
ones they must raise an appropriate flag (tbd).
Optional parameters SHOULD be used by QSMs if applicable, and
defining optional parameters facilitates interworking. However,
QNEs outside the domain employing a particular QSM cannot be
expected to understand the optional parameters.
A QSpec is specific to a QSM and is identified by a QSM ID carried
in QoS NSLP. However, as explained above, the generic parameters
contained in a QSpec are understood by any QNE, even if the
corresponding QSM is not known. Therefore a QNE SHOULD interpret the
generic parameters contained in a QSpec, even if it does not
understand the QSM. QoS NSLP provides appropriate error codes to
attach to the QSpec which indicate such a translation took place.
Hence, generic parameters ease global intelligibility of QoS NSLP
messages.
It needs to be investigated whether a minimal set of generic QSpec
parameters MUST even be implemented in any QNE: this may be
important for true interoperability of QSMs. The set of QSpec
parameters that MUST be supported could be a subset of the generic
ones defined here.
This version of the QSpec Template Draft only defines generic
parameters. Examples for optional parameters will be provided in the
future.
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4.2. QSpec Format Overview
QSpec = <QSM Control Information> <QoS Description>
As described above, the QSpec object contains the actual resource
description (QoS description) as well as QSM control information.
Both QoS description and QSM control information may contain mutable
and immutable parameters.
Mutable parameters can be changed by any QNE, including by QoS NSIS
functions along the signaling path, whereas immutable parameters are
fixed by the initiating QNE and/or responding QNEs. An example of a
mutable parameter is the path's MTU, an example of an immutable
parameter is a token bucket describing the traffic to be sent.
4.2.1. QSM Specific Control Information
QSM specific control information is used for QSpec-specific control
information and for specific signaling functions not defined in QoS-
NSLP. It enables building a new signaling model within a QoS-NSLP
signaling framework, see for example [RMD-QoS-SIG] and [RMD-QSM].
Generic parameters:
- <Hop Count>
mutable hop count field, limiting the scope of QSpec to a maximum
number of QoS-NSLP hops. <Hop Count> must not be confused with the
scope of the QoS NSLP message carrying the QSpec. This scope would
be coded in the Common Control Information.
- <Service Schedule> = <start time>, <end time> | <relative time
duration from RESPONSE>
immutable parameter, indicating the desired start time and end time
of the service, i.e. when is the service available. The values for
<end time> and <relative time duration from RESPONSE> respectively
can be infinity, in which case the reservation can be ended by the
usual tearing RESERVE. The Service Schedule parameter has two-fold
use:
a. Reservation of resources for the immediate future when the full
flow ID (e.g. port number) is still being negotiated. In this time
<start time> is set to zero.
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b. Scheduling of reservations ahead of time to make sure resources
will be available. An example is reservation of resources for a
video-conference. Also in this case the full flow ID may not be
known at the time of reservation.
Hence, in both cases the QNI sends an incomplete RESERVE prompting
the Resource Management Function to set aside resources without
actually configuring the router(s). Router configuration is
triggered by a RESERVE containing the full flow ID. Appropriate
security measures need to be taken to prevent Denial of Service
abuse of this functionality (tbd).
It needs to be considered whether Service Schedule should be an
optional parameter because supporting it involves some overhead: the
RMF needs functionality to set aside resources in advance and
configure the router(s) later. Furthermore, for large advance
reservations, it may be necessary to "phase out" ongoing
reservations much earlier than the actual reservation in order to
make sure resources will be available.
Note that even reservations that are "scheduled" need to be
refreshed just as ongoing reservations. Refresh periods are specific
to a particular state in a particular QNE [QoS-SIG]. Hence it is
conceivable that QNEs decide locally to make the refresh period for
scheduled reservations considerably longer than that for ongoing
reservations.
- Flag indicating unsuccessful reservation in stateless/reduced
state QNEs
Since in case of stateless/reduced state QoS-NSLP operation interior
nodes do not store per flow information edge nodes should be
notified about unsuccessful reservation, see further specification
in [RMD-QSM].
- Flag indicating severe congestion in stateless/reduced state QNEs
Similarly to unsuccessful reservation, in case of sever congestion
this flag may be set in refresh messages. Note that severe
congestion notification can be done also by data remarking, see more
details in [RMD-QSM].
Note that stateless/reduced state operation mode is used in some
DiffServ based QoS signaling models, see for example [RMD-QSM].
These control fields are needed because interior routers do not
store per flow QoS-NSLP states and they are used for notifying edge.
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4.2.2 QoS Description
The QoS Description objects are broken down into the following
categories:
<QoS Description> = <QoS Desired> <QoS Available> <QoS Reserved>
<Minimum QoS>
On the QSpec template level, the only restriction on object usage is
that <Minimum QoS> should always travel together with <QoS
Available> and/or <QoS Desired >. Otherwise there is no restriction
on how many of these sub-objects a QSpec may carry, nor what type of
sub-object is carried in what type of QoS NSLP message. For
example, in a receiver-initiated reservation scenario, the
initiating QNE may send a QUERY carrying a <QoS Available> sub-
object to probe the available resources on the path. The same QUERY
may carry a <QoS Desired> sub-object. The responding QNE can re-use
the latter objects in the RESERVE message. The QoS NSLP and
particularly the QSMs prescribe how the sub-objects in QSpecs are
interpreted and used, and therefore restrict this freedom.
The union of all the sub-objects identified in this Section can
provide all functionality of the objects specified in RSVP IntServ,
however it is difficult to provide an exact mapping.
In RSVP, the Sender TSpec specifies the traffic an application is
going to send (e.g. token bucket). The AdSpec can collect path
characteristics (e.g. delay). Both are issued by the sender. The
receiver sends the FlowSpec which includes a Receiver TSpec
describing the resources reserved using the same parameters as the
Sender TSpec, as well as a RSpec which provides additional IntServ
QoS Model specific parameters, e.g. Rate and Slack.
The RSVP TSpec/AdSpec/RSpec seem quite tailored to receiver-
initiated signaling employed by RSVP, and the IntServ QoS Model.
E.g. to the knowledge of the authors it is not possible for the
sender to specify a desired maximum delay except implicitly and
mutably by seeding the AdSpec accordingly. Likewise, the RSpec is
only meaningfully sent in the receiver-issued RSVP RESERVE message.
For this reason our debate at this point let us to a slightly
different mapping of necessary functionality to sub-objects, which
should result in more flexible signaling models.
Particularly, we settled for defining a "QoS Desired" rather than a
"Traffic Specification". QoS Desired may in fact just be a
description of traffic to be sent, but it may also include more
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parameters (e.g. delay) or signal for resources than those derived
from an exact traffic description (e.g. a token bucket with a higher
peak rate). Furthermore we consider to allow all sub-objects
carrying the same parameter types (to be detailed in future versions
of this draft). Hence, a QNI could send a RESERVE with QoS Desired
containing a particular average bandwidth, and at the same time
include a QoS Available sub-object for querying availability of this
same parameter. If QoS Desired cannot be reserved, the QNR can use
the information collected in QoS Available along the path to signal
back to the QNI a more promising value of QoS Desired. The details
of such message exchanges need to be fixed elsewhere.
4.2.2.1 <QoS Desired>
<QoS Desired> = <R> <token bucket> <QoS class> <Priority>
These parameters describe the traffic the QNI is going to inject
into the reservation and hence it is immutable.
<R> = reserved rate desired
<token bucket> = <r> <b> <p> <m> <M>
as defined in [RFC 2210]
<QoS-class> = <PHB> <Y.1541 QoS class> <DS-TE class type>
An application may like to reserve resources for packets with a
particular QoS class, e.g. a DiffServ per-hop behavior (PHB)
[DIFFSERV], or DiffServ-enabled
traffic engineering (DS-TE) class type [DS-TE].
<Priority> = <Emergency>
Reservation priority is an essential way to differentiate flows for
emergency services, ETS, E911, etc., and assign them a higher
priority than normal priority flows. Appropriate security measures
need to be taken to prevent abuse of this parameter. These are
immutable parameters.
There has been some debate whether such priority parameters should
be generic to all NSLPs, generic to QoS-NSLP, or generic to QSMs,
that is, where they should be defined. It is beyond the scope of
this document whether the priorities defined here are also useful in
other NSLPs. However, we believe in the context of QoS-NSLP that
priority is best placed in the QSM and QSpec. The reason is that the
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resource management function seems to function more efficiently if
priority state is held there rather than in common QoS-NSLP
processing of messages (see Figure 1). Only the resource management
function knows that resources are not sufficient and that it may be
necessary to preempt a reservation. If preemption state was
associated with QoS-NSLP state rather than with resource management
state, the resource management function would need to negotiate with
the common QoS-NSLP processing until the two work out what
reservation to preempt.
Note that although we locate priority parameters with the QSM, the
fact that we make them generic parameters could be seen as a
recommendation to implement them in all QNEs (see discussion above).
Note that QoS Desired may carry parameters like desired delay or
loss parameters, however these are optional parameters and not
specified in this document.
4.2.3.2 <QoS Available>
<QoS Available> = <non IS hop> <IS hops> <Available Bw> <Min
latency> <M> <Ctot> <Dtot> <Csum> <Dsum>
These parameters describe the resources currently available on the
path and are defined in [RFC 2210, 2212, 2215]. Each QNE must
inspect this object. If resources available to this QNE are less
than what <QoS Available> says currently, the QNE must adapt it
accordingly. Hence when the message arrives at the recipient of the
message, <QoS Available> reflects the bottleneck of the resources
currently available on a path. It can be used in a QUERY message,
for example, to collect the available resources along a data path.
4.2.3.3 <QoS Reserved>
<QoS Reserved> = <token bucket> <QoS-class> <Priority> <R> <S>
These parameters describe the QoS reserved by the QNEs down the
path. <token bucket> <QoS-class> <Priority> are defined in Sec.
4.2.2.1 above. <R> <S> are defined in [RFC 2212]. These are mutable
parameters.
4.2.3.4 <Minimum QoS>
<Minimum QoS> = <token bucket> <QoS-class> <Priority>
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<Minimum QoS> doesn't have an equivalent in RSVP. It allows the QNI
to define a range of acceptable QoS levels by including both the
desired QoS value and the minimum acceptable QoS in the same
message. The desired QoS is included with a <QoS Desired> and/or a
<QoS Available> subobject seeded to the desired QoS value. The
minimum acceptable QoS value is coded in the <Minimum QoS>
subobject. As the message travels towards the QNR, <QoS Available>
is updated by QNEs on the path. If its value drops below the value
of <Minimum QoS> the reservation failed and can be aborted. When
this method is employed it is important that the QNR signals back to
the QNI the value <QoS Available> attained in the end, because the
reservation may need to be adapted accordingly.
5. Security Considerations
The Service Schedule and Priority parameters raise possibilities for
Denial of Service Attacks. How to deal with this will be handled in
future versions of this draft.
6. Open Issues
a. A detailed discussion of QSM development guidelines needs to be
provided.
b. A more detailed specification of the generic parameters needs to
be given.
c. The relationship of common NSLP processing, QSM-specific NSLP
processing and resource management function, as well as how their
tasks differ needs, to be described more clearly. For example, how
do QSM-specific NSLP processing and the RMF influence message
processing in common NSLP processing?
d. Should/can we request that QNEs MUST implement a subset of
generic parameters?
e. May a node compose a QSpec containing more parameters than
defined in the QSM it is signaling for, e.g. for later use by other
nodes?
f. The following optional parameters have been proposed to support
other QSMs, and need to be discussed for inclusion in the next
revisions of the draft:
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i) adding the individual parameters:
<Transfer Delay>, <Delay Variation>, <Packet Loss Ratio>, and
<Packet Error Ratio> to all of the QoS Description categories:
<QoS Desired> <QoS Available> <QoS Reserved> <Minimum QoS>
ii) Generalize the priority parameter as follows:
<Priority> = <Reservation Priority> <Setup Priority> <Holding
Priority>
Where <Setup Priority> and <Holding Priority> are as specified in
RFC 3209.
g. Do we need an explicit Traffic Specification, or is a <QoS
Desired> that may not exactly describe the issued traffic
acceptable?
h. Should Service Schedule be an optional parameter because of the
overhead it may introduce?
7. Acknowledgements
The authors would like to thank Robert Hancock and Sven van den
Bosch for their helpful suggestions.
8. Intellectual Property Considerations
The IETF takes no position regarding the validity or scope of any
Intellectual Property Rights or other rights that might be claimed
to pertain to the implementation or use of the technology described
in this document or the extent to which any license under such
rights might or might not be available; nor does it represent that
it has made any independent effort to identify any such rights.
Information on the procedures with respect to rights in RFC
documents can be found in BCP 78 and BCP 79.
Copies of IPR disclosures made to the IETF Secretariat and any
assurances of licenses to be made available, or the result of an
attempt made to obtain a general license or permission for the use
of such proprietary rights by implementers or users of this
specification can be obtained from the IETF on-line IPR repository
at http://www.ietf.org/ipr.
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The IETF invites any interested party to bring to its attention any
copyrights, patents or patent applications, or other proprietary
rights that may cover technology that may be required to implement
this standard. Please address the information to the IETF at ietf-
ipr@ietf.org.
9. References
[DIFFSERV] S. Blake et. al., "An Architecture for Differentiated
Services", RFC 2475, December 1998.
[DS-TE] F. Le Faucheur et. al., Requirements for Support of
Differentiated Services-aware MPLS Traffic Engineering, RFC 3564,
July 2003
[KEY] S. Bradner, "Key words for use in RFCs to Indicate Requirement
Levels", BCP 14, RFC 2119, March 1997
[INTSERV] B. Braden et. al., "Integrated Services in the Internet
Architecture: an Overview," RFC 1633, June 1994.
[INTSERV-QoS-SIG] C. Kappler, "A QoS Model for Signaling IntServ
Controlled-Load Service with NSIS," work in progress.
[NSIS-REQ] M. Brunner et. al., "Requirements for QoS Signaling
Protocols", work in progress.
[RFC2211] J. Wroclawski, "Specification of the Controlled-Load
Network Element Service", RFC 2211, Sept. 1997.
[RFC2212} Shenker, S., et. al., "Specification of Guaranteed Quality
of Service," September 1997.
[RFC2215] S. Shenker and J. Wroclawski, "General Characterization
Parameters for Integrated Service Network Elements", RFC 2215, Sept.
1997.
[RMD-QoS-SIG] A. Bader et. al., "RMD (Resource Management in
Diffserv) QoS-NSLP model", work in progress.
[RMD-QSM] A. Bader, L. Westberg, G. Karagiannis, C. Kappler and T.
Phelan, "Resource Management for DiffServ QoS Signaling Model"
<draft-ietf-nsis-rmd-diffserv-00>, work in progress.
[RSVP] B. Braden et. al., "Resource ReSerVation Protocol (RSVP) --
Version 1 Functional Specification," RFC 2205, September 1997.
[RSVP-INTSERV] J. Wroclawski, "The Use of RSVP with IETF Integrated
Services", RFC 2210, September 1997.
[TRQ-QoS-SIG] J. Ash et. al., "NSIS Network Service Layer Protocol
QoS Signaling Proof-of-Concept," work in progress.
[QoS-SIG] S. Van den Bosch et. al., "NSLP for Quality-of-Service
Signaling," work in progress.
[Y.1541] ITU-T Recommendation Y.1541, "Network Performance
Objectives for IP-Based Services," May 2002.
[Q.2630] ITU-T Recommendation Q.2630.3: "AAL Type 2 Signaling
Protocol - Capability Set 3" Sep. 2003
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10. Authors' Addresses
Jerry Ash
AT&T
Room MT D5-2A01
200 Laurel Avenue
Middletown, NJ 07748, USA
Phone: +1-(732)-420-4578
Fax: +1-(732)-368-8659
Email: gash@att.com
Attila Bader
Traffic Lab
Ericsson Research
Ericsson Hungary Ltd.
Laborc u. 1 H-1037
Budapest Hungary
EMail: Attila.Bader@ericsson.com
Chuck Dvorak
AT&T
Room 2A37
180 Park Avenue, Building 2
Florham Park, NJ 07932
Phone: + 1 973-236-6700
Fax:+1 973-236-7453
E-mail: cdvorak@att.com
Yacine El Mghazli
Alcatel
Route de Nozay
91460 Marcoussis cedex
FRANCE
Phone: +33 1 69 63 41 87
Email: yacine.el_mghazli@alcatel.fr
Cornelia Kappler
Siemens AG
Siemensdamm 62
Berlin 13627
Germany
Email: cornelia.kappler@siemens.com
Georgios Karagiannis
University of Twente
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Internet Draft QoS-NSLP QSpec Template September 2004
P.O. BOX 217
7500 AE Enschede
The Netherlands
EMail: g.karagiannis@ewi.utwente.nl
Andrew McDonald
Siemens/Roke Manor Research
Roke Manor Research Ltd.
Romsey, Hants SO51 0ZN
UK
EMail: andrew.mcdonald@roke.co.uk
Al Morton
AT&T
Room D3-3C06
200 S. Laurel Avenue
Middletown, NJ 07748
Phone: + 1 732 420-1571
Fax: +.1 732 368-1192
E-mail: acmorton@att.com
Percy Tarapore
AT&T
Room D1-3D33
200 S. Laurel Avenue
Middletown, NJ 07748
Phone: + 1 732 420-4172
E-mail: tarapore@.att.com
Lars Westberg
Ericsson Research
Torshamnsgatan 23
SE-164 80 Stockholm, Sweden
EMail: Lars.Westberg@ericsson.com
Appendix A: Example QSpecs
Note the mere definition of QSpecs is not sufficient for determining
how to signal for DiffServ and IntServ respectively. Rather, the
full QSM needs to be defined.
A.1 QSpec for Admission Control for DiffServ
QSpec for Diffserv QSM in general may be provided in future versions
of this draft. A QSpec for a DiffServ QSM, RMD is partically
included in [RMD-QSM].
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A.2 QSpec for IntServ Controlled Load Service
The QoS Model for IntServ Controlled Load is defined in [RFC2211].
The QSpec can be derived from usage of RSVP to signal for this QoS
Model, as defined in [RSVP-INTSERV] and [RFC2215].
The QSpec for IntServ Controlled Load is composed of the subobjects
<QoS Desired> and <QoS Available>, as well as <QoS Reserved>. Which
sub-object is present in a particular QSpec depends on the message
type (RESERVE, QUERY etc) in which the QSpec travels. Details must
be provided in a corresponding QSM. Parameters in the QSpec are as
follows:
<QoS Desired> = <token bucket>
<QoS Available> = <non IS hop> <IS hops> <Available Bw> <Min
latency> <M>
<QoS Reserved> = <token bucket>
A.3 QSpec for IntServ Guaranteed Services
The QoS Model is defined in [RFC 2212]. The required parameters to
achieve guarantied service with RSVP are specified in [RFC 2210] and
[RFC 2215].
The QSpec for guarantied services is the following:
<QoS Description> = <QoS Desired> <QoS Available> <QoS Reserved>
<QoS Desired> = <token bucket>
This sub-object contains token bucket parameters defined in [RFC
2210]. Equivalent to TSpec defined in RSVP.
<QoS Available> = <non IS hop> <IS hops> <Available Bw> <Min
latency> <MTU> <Ctot> <Dtot> <Csum> <Dsum>
These parameters are defined in [RFC 2212] and [RFC 2215]. This sub-
object is equivalent to AdSpec of RSVP.
<QoS Reserved> = <token bucket> <R> <S>
Requested Rate and Slack Term defined in [RFC 2212], equivalent to
RSpec of RSVP.
Note that the Guarantied Services QoS Model only works with receiver
initiated reservation signaling, because <R> and <S> are derived
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from parameters contained in <QoS Available>, and may be updated on
the return paths.
Appendix B: QoS Models, QoS Signaling Models and QSpecs
This section gives a description of QoS models, QSMs and QSpecs and
explains what is the relation between them. Once these descriptions
are contained in a stable form in the appropriate IDs this Appendix
will be removed.
QoS NSLP is a generic QoS Signaling Protocol that can signal for
many QoS Models. A QoS Model is a particular QoS provisioning method
or QoS architecture such a IntServ Controlled Load, Guaranteed
Service. DiffServ, or RMD for DiffServ.
The definition of the QoS Model is independent from the definition
of QoS NSLP. Existing QoS Models do not specify how to use QoS NSLP
to signal for them. Therefore, we need to define the QoS Signaling
Models (QSMs), specific to each QoS Model, which describes the QoS
Model specific signaling functions. QoS Signaling Model are defined
for "Resource Management in DiffServ" in [RMD-QSM] and for IntServ
Controlled Load in [INTSERV-QoS-SIG].
A QSM should include the following information:
- Role of QNEs in this QoS Model:
E.g. location, frequency, statefulness...
- QSpec Definition:
A QSM should specify the QSpec, including generic and optional
parameters. Furthermore it needs to explain how generic parameters
not used in this QSM are mapped onto parameters defined therein.
- Message Format
Objects to be carried in RESERVE, QUERY RESPONSE and NOTIFY
- State Management
It describes how QSpec info is treated and interpreted in the
Resource Management Function and QSM specific processing. E.g.
admission control, scheduling, policy control, QoS parameter
accumulation (e.g. delay)à
- Operation and Sequence of Events
Usage of QoS-NSLP messages to signal the QoS model.
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Disclaimer of Validity
This document and the information contained herein are provided on
an "AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE
REPRESENTS OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY AND THE
INTERNET ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF
THE INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED
WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
Full Copyright Statement
Copyright (C) The Internet Society (2004). This document is subject
to the rights, licenses and restrictions contained in BCP 78, and
except as set forth therein, the authors retain all their rights.
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