One document matched: draft-ietf-nsis-qspec-03.txt
Differences from draft-ietf-nsis-qspec-02.txt
IETF Internet Draft NSIS Working Group Jerry Ash
Internet Draft AT&T
<draft-ietf-nsis-qspec-03.txt> Attila Bader
Expiration Date: August 2005 Ericsson
Cornelia Kappler
Siemens AG
February 2005
QoS-NSLP QSPEC Template
Status of this Memo
By submitting this Internet-Draft, each author represents that any
applicable patent or other IPR claims of which he or she is aware
have been or will be disclosed, and any of which he or she becomes
aware will be disclosed, in accordance with Section 6 of RFC 3668.
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Copyright Notice
Copyright (C) The Internet Society (2005). All Rights Reserved.
Abstract
The QoS NSLP protocol is used to signal QoS reservations and is
independent of a specific QoS model (QOSM) such as IntServ or
DiffServ. Rather, all information specific to a QOSM is encapsulated
in a separate object, the QSPEC. This draft defines a template for
the QSPEC, which contains both the QoS description and QSPEC control
information. The QSPEC format is defined, as are a number of QSPEC
parameters. The QSPEC parameters provide a common language to be
re-used in several QOSMs, which are derived initially from the
IntServ and DiffServ QOSMs. To a certain extent QSPEC parameters
ensure interoperability of QOSMs. Optional QSPEC parameters aim to
ensure the extensibility of QoS NSLP to other QOSMs in the future.
The node initiating the NSIS signaling adds an Initiator QSPEC that
must not be removed, thereby ensuring the intention of the NSIS
initiator is preserved along the signaling path.
Ash, et. al. <draft-ietf-nsis-qspec-03.txt> [Page 1]
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Table of Contents
1. Conventions Used in This Document . . . . . . . . . . . . . 3
2. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
3. Terminology . . . . . . . . . . . . . . . . . . . . . . . . 4
4. QSPEC Parameters, Processing, & Extensibility . . . . . . . 5
4.1 QSPEC Parameters . . . . . . . . . . . . . . . . . . . . 5
4.2 QSPEC Processing . . . . . . . . . . . . . . . . . . . . 5
4.3 Example of NSLP QSPEC Operation . . . . . . . . . . . . 6
4.4 Treatment of Mandatory & Optional QSPEC Parameters . . . 8
4.5 QSPEC Extensibility. . . . . . . . . . . . . . . . . . . 8
5. QSPEC Format Overview . . . . . . . . . . . . . . . . . . . 9
5.1 QSPEC Control Information . . . . . . . . . . . . . . . 9
5.2 QoS Description . . . . . . . . . . . . . . . . . . . . 10
5.2.1 QoS Desired . . . . . . . . . . . . . . . . . . . 10
5.2.2 QoS Available . . . . . . . . . . . . . . . . . . 11
5.2.3 QoS Reserved . . . . . . . . . . . . . . . . . . . 13
5.2.4 Minimum QoS . . . . . . . . . . . . . . . . . . . 13
6. QSPEC Functional Specification . . . . . . . . . . . . . . . 13
6.1 General QSPEC Formats . . . . . . . . . . . . . . . . . 13
6.2 <Max NSLP Hops> Parameter . . . . . . . . . . . . . . . 14
6.3 <NON NSLP Hop> & <NSLP Hops> Parameters . . . . . . . . 14
6.4 <Excess Treatment> Parameter . . . . . . . . . . . . . . 15
6.5 <Bandwidth> & <S> Parameters . . . . . . . . . . . . . . 15
6.6 <Token Bucket> Parameters . . . . . . . . . . . . . . . 15
6.7 <QoS Class> Parameters . . . . . . . . . . . . . . . . . 16
6.7.1 <PHB Class> Parameter . . . . . . . . . . . . . . 16
6.7.2 <Y.1541 QoS Class> Parameter . . . . . . . . . . . 16
6.7.3 <DSTE Class Type> Parameter . . . . . . . . . . . 17
6.8 <Priority> Parameters . . . . . . . . . . . . . . . . . 17
6.8.1 <Preemption Priority> & <Defending Priority>
Parameters . . . . . . . . . . . . . . . . . . . . 17
6.8.2 <Reservation Priority> Parameter . . . . . . . . . 18
6.9 <QoS Available> Parameters . . . . . . . . . . . . . . . 19
6.9.1 <Path Latency> Parameter . . . . . . . . . . . . . 19
6.9.2 <Path Jitter> Parameter . . . . . . . . . . . . . 19
6.9.3 <Path BER> Parameter . . . . . . . . . . . . . . . 20
6.9.4 <Ctot> <Dtot> <Csum> <Dsum> Parameters . . . . . . 20
7. Security Considerations . . . . . . . . . . . . . . . . . . 21
8. IANA Considerations . . . . . . . . . . . . . . . . . . . . 21
9. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 21
10. Intellectual Property Considerations . . . . . . . . . . . 21
11. Normative References . . . . . . . . . . . . . . . . . . . 22
12. Informative References . . . . . . . . . . . . . . . . . . 22
13. Authors' Addresses . . . . . . . . . . . . . . . . . . . . 23
Appendix A Example QSPECs . . . . . . . . . . . . . . . . . . . 24
A.1 QSPEC for Admission Control for DiffServ . . . . . . . . . 24
A.2 QSPEC for IntServ Controlled Load Service . . . . . . . . . 24
A.3 QSPEC for IntServ Guaranteed Services . . . . . . . . . . . 25
Appendix B QoS Models and QSPECs . . . . . . . . . . . . . . . 25
Appendix C Mapping of QoS Desired, QoS Available, and QoS
Reserved of NSIS onto AdSpec, TSpec, and RSpec of RSVP IntServ. 26
Full Copyright Notice . . . . . . . . . . . . . . . . . . . . . 27
Disclaimer of Validity . . . . . . . . . . . . . . . . . . . . 27
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1. 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 RFC 2119 [RFC2119].
2. 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 [RFC2205], and meets the requirements of [RFC3726].
A QoS-enabled domain supports a particular QoS model (QOSM), which is
a methodology to achieve QoS for a traffic flow that incorporates QoS
provisioning methods and a QoS architecture. A QOSM defines the
behavior of the resource management function (RMF), including inputs
and outputs, and how QSPEC information is interpreted on traffic
description, resources required, resources available, and control
information required by the RMF. A QOSM also specifies a set of
mandatory and optional QSPEC parameters that describe the QoS and how
resources will be managed by the RMF. QoS NSLP can support signaling
for different QOSMs, such as for IntServ, DiffServ admission control,
and those specified in [Y.1541-QOSM, INTSERV-QOSM, RMD-QOSM]. For
more information on QOSMs see Appendix B.
One of the major differences between RSVP and QoS-NSLP is that
QoS-NSLP supports signaling for different QOSMs along the data path,
all with one signaling message. For example, the data path may start
in a domain supporting DiffServ and end in a domain supporting
Y.1541. However, because some typical QoS parameters are
standardized and can be reused in different QOSMs, some degree of
interoperability between QOSMs exists.
The QSPEC object travels in QoS-NSLP messages and is opaque to the
QoS NSLP. The content of the QSPEC object is QOSM specific. Since
QoS-NSLP signaling operation can be different for different QOSMs,
the QSPEC contains two kinds of information, QSPEC control
information and QoS description.
QSPEC control information contains parameters that governs the RMF.
An example of QSPEC control information is how the excess traffic is
treated in the RMF queuing functions.
The QoS description is composed of objects loosely 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 an object denoting minimum QoS.
Usage of these 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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3. Terminology
Mandatory QSPEC parameter: QSPEC parameter that a QNI SHOULD
populate if applicable to the underlying QOSM and a QNE MUST
interpret, if populated.
Minimum QoS: Minimum QoS is a functionality that MAY be supported by
any QNE. 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, QNEs are going to decrease the
reservation until the minimum QoS is hit.
Optional QSPEC parameter: QSPEC parameter that a QNI SHOULD populate
if applicable to the underlying QOSM, and a QNE SHOULD interpret if
populated and applicable to the QOSM(s) supported by the QNE. (A QNE
MAY ignore if it does not support a QOSM needing the optional QSPEC
parameter).
QNE: QoS NSIS Entity, a node supporting QoS NSLP.
QNI: QoS NSIS Initiator, a node initiating QoS NSLP signaling.
QNR: QoS NSIS Receiver, a node terminating QoS NSLP signaling.
QoS Description: Describes the actual QoS in objects QoS Desired,
QoS Available, QoS Reserved, and Minimum QoS. These objects are
input or output parameters of the RMF. In a valid QSPEC, at least
one object of the type QoS Desired, QoS Available or QoS Reserved
MUST be included.
QoS Available: Object containing parameters describing the available
resources. They are used to collect information along a reservation
path.
QoS Desired: Object containing parameters describing the desired QoS
for which the sender requests reservation.
QoS Model (QOSM): A methodology to achieve QoS for a traffic flow,
e.g., IntServ Controlled Load. Specifies a set of mandatory and
optional QSPEC parameters that describe the QoS and how resources
will be managed by the RMF.
QoS Reserved: Object containing parameters describing the reserved
resources and related QoS parameters, for example, bandwidth.
QSPEC Control Information: Control information that is specific to a
QSPEC, and contains parameters that govern the RMF.
QSPEC: QSPEC is the object of QoS-NSLP containing all QOSM specific
information.
QSPEC parameter: Any parameter appearing in a QSPEC; includes both
QoS description and QSPEC control information parameters, for
example, bandwidth, token bucket, and excess treatment parameters.
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QSPEC object: Main building blocks of QoS Description containing a
parameter set that is input or output of an RMF operation.
Resource Management Function (RMF): Functions that are related to
resource management, specific to a QOSM. It processes the QoS
description parameters and QSPEC control parameters.
Read-only Parameter: Parameter that is set by initiating or
responding QNE and is not changed during the processing of the QSPEC
along the path.
Read-write Parameter: Parameter that can be changed during the
processing of the QSPEC by any QNE along the path.
4. QSPEC Parameters, Processing, & Extensibility
4.1 QSPEC Parameters
The definition of a QOSM includes the specification of how the
requested QoS resources will be described and how they will be
managed by the RMF. For this purpose, the QOSM specifies a set of
QSPEC parameters that describe the QoS and QoS resource control
in the RMF. A given QOSM defines which of the mandatory and optional
QSPEC parameters it uses, and it MAY define additional optional QSPEC
parameters. Mandatory and optional QSPEC parameters provide a common
language for QOSM developers to build their QSPECs and are likely to
be re-used in several QOSMs. Mandatory and optional QSPEC parameters
are defined in this document, and additional optional QSPEC
parameters
can be defined in separate documents. Specification of additional
optional QSPEC parameters requires standards action, as defined in
Section 4.5.
4.2 QSPEC Processing
The QSPEC is opaque to the QoS-NSLP processing. The QSPEC control
information and the QoS description are interpreted and MAY be
modified by the RMF in a QNE (see description in [QoS-SIG]).
A QoS-enabled domain supports a particular QOSM, e.g. DiffServ. If
this domain supports QoS-NSLP signaling, its QNEs MUST support the
DiffServ QOSM. The QNEs MAY also support additional QOSMs.
A QoS NSLP message can contains a stack of 1+n QSPECs. The first on
the stack is the Initiator QSPEC. This is a QSPEC provided by the
QNI, which travels end-to-end, and therefore the stack always has at
least depth 1. QSPEC parameters MUST NOT be deleted from or added to
the Initiator QSPEC. In addition, the stack MAY contain n Local
QSPECs stacked on top of the Initiator QSPEC, where n is the level of
nested QOSM regions. In most cases, we expect the QSPEC stack to be
no deeper than 2. A QNE only considers the topmost QSPEC.
At the ingress edge of a local QoS domain, a Local QSPEC MAY be
pushed on the stack in order to describe the requested resources in a
domain-specific manner. Also, the Local QSPECs are popped from the
stack at the egress edge of the local QoS domain.
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This draft provides a template for the QSPEC, which is needed in
order to help defining individual QOSMs and in order to promote
interoperability between QOSMs. Figure 1 illustrates how the QSPEC
is composed of QSPEC control information and QoS description. QoS
description in turn is composed of up to four objects (not all of
them need to be present), namely QoS desired, QoS available, QoS
reserved and Minimum QoS. Each of these objects, as well as QSPEC
control information, consists of a number of mandatory and optional
QSPEC parameters.
+-----------------------+----------------------------------------+
| QSPEC control info | QoS description |
+-----------------------+----------------------------------------+
\________________ ______________________/
V
+----------+-----------+----------+-------+
|QoS Desir.|QoS Avail. |QoS Rsrv. |Min QoS|
+----------+-----------+----------+-------+
\__________ ___________/\_____ ____/\___ ______/\___ _____/\__ ___/
V V V V V
+-------------+... +-------------+...
|QSPEC para. 1| |QSPEC para. n|
+-------------+... +-------------+...
Figure 1: Structure of the QSPEC
The Initiator QSPEC additionally MAY contain optional QSPEC
parameters in each object and in the QSPEC control information, as
illustrated in Figure 2.
+---------------+------------------------------+------------------------
-+
|QSPEC Object ID| Mandatory QSPEC Parameters |Optional QSPEC
Parameters|
+---------------+------------------------------+------------------------
-+
Figure 2: Structure of Initiator & Local QSPEC Objects & Control
Information
4.3 Example of NSLP/QSPEC Operation
This Section illustrates the operation and use of the QSPEC within
the NSLP. The example configuration in shown in Figure 3.
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+----------+ /-------\ /--------\ /--------\
| Laptop | | Home | | Cable | | Diffserv |
| Computer |-----| Network |-----| Network |-----| Network |----+
+----------+ | No QOSM | |DQOS QOSM | | RMD QOSM | |
\-------/ \--------/ \--------/ |
|
+-----------------------------------------------+
|
| /--------\ +----------+
| | "X"G | | Handheld |
+---| Wireless |-----| Device |
| XG QOSM | +----------+
\--------/
Figure 3: Example Configuration to Illustrate NSLP/QSPEC Operation
In this configuration, a laptop computer and a handheld wireless
device are the end points for some application that has QoS
requirements. Assume that the two end points are stationary during
the application session. For this session, the laptop computer is
connected to a home network that has no QoS support. The home
network is connected to a CableLabs-type cable access network with
dynamic QoS (DQOS) support, such as specified in the 'CMS to CMS
Signaling Specification' [CMSS] for cable access networks. That
network is connected to a Diffserv core network that uses the RMD
QOSM. On the other side of the Diffserv core is a wireless
access network built on generation "X" technology with QoS support as
defined by generation "X". And finally the handheld endpoint is
connected to the wireless access network.
We assume that the Laptop is the QNI and Handheld Device is the QNR.
The QNI will populate an Initiator QSPEC to achieve the QoS desired
on the path. There are two cases to consider:
Case 1) The QNI knows, either by discovery or configuration, the
QOSMs supported in the downstream domains, and populates the
appropriate mandatory and optional QSPEC parameters to achieve the
QNI's desired QoS.
Case 2) The QNI does not know which QOSMs are supported in the
downstream domains, and populates appropriate mandatory and optional
QSPEC parameters so that downstream QNEs can interpret the parameters
to achieve the QNI's desired QoS.
In case 1, the Laptop-QNI discovers which QOSMs are supported on the
data path by sending a QUERY message along the data path. The
RESPONSE message indicates the preferred QOSM supported in the
domains along the path. The Laptop-QNI then knows that the RMD-QOSM
and XG-QOSM are in the path and populates the appropriate mandatory
and optional QSPEC parameters needed by the RMD-QSPEC and XG-QSPEC in
the Initiator QSPEC sent in the RESERVE message.
In case 2, the QNI populates mandatory and optional QSPEC parameters
to ensure correct treatment of its traffic in domains down the path.
Since the QNI does not know the QOSM used in downstream domains, it
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includes values for all mandatory and optional QSPEC parameters it
cares about. For example, if the QNI wants to achieve IntServ-like
QoS guarantees, it would include parameters for IntServ Guaranteed
Service. Since these parameters give a very precise description of
what is desired, QNEs can do their best to satisfy the request. If
the QNI thinks DiffServ priority treatment would be sufficient, it
just includes the appropriate DiffServ parameters, for example, it
identifies the EF PHB in the <QoS Class> parameters.
In both cases, each QNE on the path reads and interprets the
parameters in the Initiator QSPEC that it needs to implement the QOSM
within its domain. For example, at the RMD and XG network ingress,
a Local QSPEC corresponding to the RMD-QOSM and XG-QOSM are
generated, respectively, according to the procedures described in
Section 4.5 of [QoS-SIG]. That is, the RMD-QNI and XG-QNI must map
the mandatory and optional QSPEC parameters contained in the
Initiator QSPEC into the appropriate Local QSPEC objects to be pushed
on top of the Initiator QSPEC within the RMD and XG domains,
respectively. For example, in the RMD domain the <Bandwidth>
parameter is read if available from the Initiator QSPEC, or
alternatively it interprets the needed bandwidth parameter based on
<Token Bucket> parameters in the Initiator QSPEC.
This top Local QSPEC becomes the current QSPEC used within the RMD
and XG domain, that is, the translated Initiator QSPEC becomes the
first (Local) QSPEC, and the Initiator QSPEC is second. This saves
the QNEs within the RMD and XG domains the trouble of re-translating
the Initiator QSPEC. At the egress edge of the RMD and XG domains,
the translated QSPEC is popped, and the Initiator QSPEC returns to
the number one position. Eventually the RESERVE request arrives at
the QNR.
4.4 Treatment of QSPEC Parameters
Mandatory and optional QSPEC parameters are defined in this document
and are applicable to a number of QOSMs. Mandatory QSPEC parameters
are treated as follows:
o A QNI SHOULD populate mandatory QSPEC parameters if applicable to
the underlying QOSM.
o QNEs MUST interpret mandatory QSPEC parameters, if populated.
Optional QSPEC parameters are treated as follows:
o A QNI SHOULD populate optional QSPEC parameters if applicable to
the underlying QOSM.
o QNEs SHOULD interpret optional QSPEC parameters, if populated and
applicable to the QOSM(s) supported by the QNE. (A QNE MAY ignore
if it does not support a QOSM needing the optional QSPEC
parameter).
4.5 QSPEC Extensibility
Additional optional QSPEC parameters MAY need to be defined in the
future. Additional optional QSPEC parameters are defined in separate
Informational documents specific to a given QOSM.
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5. QSPEC Format Overview
QSPEC = <QSPEC Control Information> <QoS Description>
As described above, the QSPEC object contains the actual resource
description (QoS description) as well as QSPEC control information.
Both QoS description and QSPEC control information MAY contain
read-write and read-only objects.
Read-write objects can be changed by any QNE, whereas read-only
objects are fixed by the QNI and/or QNR. An example of a read-write
object is <QoS Available>, which is updated by intermediate QNEs.
An example of a read-only object is <QoS Desired> as sent by the QNI.
Note that all QSPEC parameters defined in the following Sections are
mandatory QSPEC parameters unless specifically designated as optional
QSPEC parameters.
5.1. QSPEC Control Information
QSPEC control information is used for signaling QOSM RMF functions
not defined in QoS-NSLP. It enables building new RMF functions
required by a QOSM within a QoS-NSLP signaling framework, see for
example [RMD-QOSM] and [Y.1541-QOSM].
<QSPEC Control Information> = <NON NSLP Hop> <NSLP Hops>
<Max NSLP Hops> <Excess Treatment>
This is a read-write object.
<NON NSLP Hop> is a flag bit telling the QNR (or QNI in a RESPONSE
message) whether or not a completely reservation-capable path
exists between the QNI and QNR. If the QNR finds this bit set, at
least one QNE along the data transmission path between the QNI and
QNR can not support QoS-NSLP/QSPEC at all. If this bit is set, the
values of all other parameters in the <QoS Available> are unreliable.
<NSLP Hops> parameter indicates the number of QoS NSLP peers along
the path the QNE MUST support and characterize the service in
conformance with the relevant QoS-NSLP/QSPEC specification, and if it
does not it MUST correctly set the <NON NSLP Hop> flag parameter.
The composition rule for this parameter is to increment the counter
by one at each QoS-NSLP/QSPEC-aware hop. This quantity, when
composed from the QNI to QNR, informs the QNR (or QNI in a RESPONSE
message) of the number of QoS-NSLP/QSPEC-aware QNEs traversed along
the path. In a local QSPEC, <NSLP Hops> and <NON NSLP hop> refer to
the NSLP nodes of the local QOSM.
<Max NSLP Hops>parameter limits the maximum number of QoS-NSLP hops.
If <Max NSLP Hops> is reached, the NSLP message SHOULD be terminated.
<Excess Treatment> parameter describes how the QNE will process
excess traffic, that is, out-of-profile traffic. Excess traffic MAY
be dropped, shaped and/or remarked. The excess treatment parameter is
initially set by the QNI and adjusted as needed by QNEs.
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5.2 QoS Description
The QoS Description is broken down into the following objects:
<QoS Description> = <QoS Desired> <QoS Available> <QoS Reserved>
<Minimum QoS>
Of these objects, QoS desired, QoS available and QoS reserved MUST be
supported by QNEs. Minimum QoS MAY be supported. QoS Desired and
Minimum QoS are read-only, whereas QoS Available and QoS Reserved are
read-write. If it needs to be ensured that QoS Desired and Minimum
QoS are indeed not changed along the path, it is possible to apply
selective protection of these objects only. The verification is
based on cryptographic procedures.
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 objects a QSPEC may carry, nor what type of object is
carried in what type of QoS NSLP message. For example, in a
receiver-initiated reservation scenario, the QNI MAY send a QUERY
carrying a <QoS Available> object to probe the available resources
on the path. The same QUERY MAY carry a <QoS Desired> object. The
responding QNE can re-use the latter objects in the RESERVE message.
A QNI could send a RESERVE with <QoS Desired> containing a particular
<Bandwidth> parameter, and at the same time include a <QoS Available>
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 are defined in [QoS-Sig]. The QoS NSLP and particularly
the QOSMs prescribe how the objects in QSPECs are interpreted and
used, and therefore MAY restrict this freedom.
5.2.1 <QoS Desired>
<QoS Desired> = <Traffic Description> <QoS Class> <Priority>
These parameters describe the resources the QNI desires to reserve
and hence this is a read-only object. <QoS Desired> includes a
description of the traffic the QNI is going to inject into the
network.
<Traffic Description> = <Bandwidth> <Token Bucket>
<Bandwidth> = link bandwidth needed by flow [RFC 2212, RFC 2215]
<Token Bucket> = <r> <b> <p> <m> <M> [RFC 2210]
<QoS Class> = <PHB Class> <Y.1541 QoS Class> <DSTE Class Type>
An application MAY like to reserve resources for packets with a
particular QoS class, e.g. a DiffServ per-hop behavior (PHB)
[RFC2475], or DiffServ-enabled MPLS traffic engineering (DSTE) class
type [RFC3564].
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<Priority> = <Reservation Priority> <Preemption Priority>
<Defending Priority>
<Reservation priority> is an essential way to differentiate flows for
emergency services, ETS, E911, etc., and assign them a higher
admission priority than normal priority flows and best-effort
priority flows. <Preemption Priority> is the priority of the new
flow compared with the defending priority of previously admitted
flows. Once a flow was admitted, the preemption priority becomes
irrelevant. <Defending Priority> is used to compare with the
preemption priority of new flows. For any specific flow, its
preemption priority MUST always be less than or equal to the
defending priority.
Appropriate security measures need to be taken to prevent abuse of
the <Priority> parameters.
5.2.2 <QoS Available>
<QoS Available> = <Traffic Description> <Path Latency> <Path Jitter>
<Path BER> <Ctot> <Dtot> <Csum> <Dsum> <Priority>
<Path Latency>, <Path Jitter>, <Path BER>, <Ctot>, <Dtot>, <Csum>,
and <Dsum> are optional QSPEC parameters.
These parameters describe the resources currently available on the
path and hence the object is read-write. Each QNE MUST inspect this
object, and 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. The <QoS
Available> parameters are defined in [RFC 2210, 2212, 2215].
The <Traffic Description> parameters provide information, for
example, about the bandwidth available along the path followed by a
data flow. The local parameter is an estimate of the bandwidth the
QNE has available for packets following the path. Computation of the
value of this parameter SHOULD take into account all information
available to the QNE about the path, taking into consideration
administrative and policy controls on bandwidth, as well as physical
resources. The composition rule for this parameter is the MIN
function. The composed value is the minimum of the QNE's value and
the previously composed value. This quantity, when composed
end-to-end, informs the QNR (or QNI in a RESPONSE message) of the
minimal bandwidth link along the path from QNI to QNR.
The <Path Latency> parameter accumulates the latency of the packet
forwarding process associated with each QNE, where the latency is
defined to be the smallest possible packet delay added by each QNE.
This delay results from speed-of-light propagation delay, from packet
processing limitations, or both. It does not include any variable
queuing delay which may be present. Each QNE MUST add the
propagation delay of its outgoing link, which includes the QNR adding
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the associated delay for the egress link. Furthermore, the QNI MUST
add the propagation delay of the ingress link. The composition rule
for the <Path Latency> parameter is summation with a clamp of
(2**32 - 1) on the maximum value. This quantity, when composed
end-to-end, informs the QNR (or QNI in a RESPONSE message) of the
minimal packet delay along the path from QNI to QNR. The purpose of
this parameter is to provide a minimum path latency for use with
services which provide estimates or bounds on additional path delay
[RFC 2212]. Together with the queuing delay bound, this parameter
gives the application knowledge of both the minimum and maximum
packet delivery delay. Knowing both the minimum and maximum latency
experienced by data packets allows the receiving application to know
the bound on delay variation and de-jitter buffer requirements.
The <Path Jitter> parameter accumulates the jitter of the packet
forwarding process associated with each QNE, where the jitter is
defined to be the nominal jitter added by each QNE. IP packet
jitter, or delay variation, is defined in RFC 3393 [RFC3393], Section
4.6 (Type-P-One-way-peak-to-peak-ipdv), where the suggested
evaluation interval is 1 minute. Note that the method to estimate
peak-to-peak IP delay variation without active measurements requires
more study. This jitter results from packet processing limitations,
and includes any variable queuing delay which may be present. Each
QNE MUST add the jitter of its outgoing link, which includes the QNR
adding the associated jitter for the egress link. Furthermore, the
QNI MUST add the jitter of the ingress link. The composition rule
for the <Path Jitter> parameter is summation of a large percentage of
the peak-to-peak variation with a clamp on the maximum value (note
that the methods of accumulation and estimation of nominal QNE jitter
is under study). This quantity, when composed end-to-end, informs
the QNR (or QNI in a RESPONSE message) of the nominal packet jitter
along the path from QNI to QNR. The purpose of this parameter is to
provide a nominal path jitter for use with services that provide
estimates or bounds on additional path delay [RFC 2212]. Together
with the <Path Latency> and the queuing delay bound, this parameter
gives the application knowledge of the typical packet delivery delay
variation.
The <Path BER> parameter accumulates the bit error rate (BER) of the
packet forwarding process associated with each QNE, where the BER is
defined to be the smallest possible BER added by each QNE. Each QNE
MUST add the BER of its outgoing link, which includes the QNR adding
the associated BER for the egress link. Furthermore, the QNI MUST
add the BER of the ingress link. The composition rule for the
<Path BER> parameter is summation with a clamp on the maximum value
(this assumes sufficiently low BER values such that summation error
is not significant). This quantity, when composed end-to-end,
informs the QNR (or QNI in a RESPONSE message) of the minimal packet
BER along the path from QNI to QNR. As with <Jitter>, the method to
estimate <Path BER> requires more study.
<Ctot>, <Dtot>, <Csum>, <Dsum>: Error terms C and D represent how the
element's implementation of the guaranteed service deviates from the
fluid model. These two parameters have an additive composition rule.
The error term C is the rate-dependent error term. It represents the
delay a datagram in the flow might experience due to the rate
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parameters of the flow. The error term D is the rate-independent,
per-element error term and represents the worst case non-rate-based
transit time variation through the service element. If the
composition function is applied along the entire path to compute the
end-to-end sums of C and D (<Ctot> and <Dtot>) and the resulting
values are then provided to the QNR (or QNI in a RESPONSE message).
<Csum> and <Dsum> are the sums of the parameters C and D between the
last reshaping point and the current reshaping point.
5.2.3 <QoS Reserved>
<QoS Reserved> = <Traffic Description> <QoS Class> <Priority> <S>
These parameters describe the QoS reserved by the QNEs down the path,
and hence the object is read-write.
<Traffic Description>, <QoS Class> and <Priority> are defined above.
<S> = slack term: difference between desired delay and delay obtained
by using bandwidth reservation <Bandwidth> (used to reduce resource
reservation for flow) [RFC 2212].
5.2.4 <Minimum QoS>
<Minimum QoS> = <Traffic Description> <QoS Class> <Priority>
<Minimum QoS> does not 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.
It is a read-only object. The desired QoS is included with a <QoS
Desired> and/or a <QoS Available> object seeded to the desired QoS
value. The minimum acceptable QoS value MAY be coded in the <Minimum
QoS> object. 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 the QNR SHOULD signal back to the QNI the value
<QoS Available> attained in the end, because the reservation MAY need
to be adapted accordingly.
Future versions of this document will describe how <Minimum QoS> can
be used by the QNI to send a discrete set of desired parameters.
6. QSPEC Functional Specification
This Section defines the encodings of the QSPEC parameters and QSPEC
control information defined in Section 4. We first give the general
QSPEC formats and then the formats of the QSPEC objects.
6.1 General QSPEC Formats:
Note: This section is in a first draft state and further work is
needed to define exact formats of objects.
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Type: QSPEC
Length: Variable
Value: This object contains a 2 byte QOSM ID and variable length
QSPEC information, which is QOSM specific.
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| QOSM ID | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Object ID | Parameter ID | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
// Parameter Values //
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Object ID | Parameter ID | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
// Parameter Values //
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
....
Object ID:
0: control information
1: QoS Desired
2: QoS Available
3: QoS Reserved
4: Min QoS
6.2 <NON NSLP Hop> & <NSLP Hops> Parameters [RFC 2210, 2215]
0 1
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| NON NSLP Hop | NSLP Hops |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
NON NSLP Hop: 8 bits
This field is set to 1 if a non NSLP-aware QNE is encountered on
the path from the QNI to the QNR.
NSLP Hops: 8 bits
Indicates the number of NSLP hops between the QNI and QNR.
Values of the composed parameter will range from 1 to 255,
limited by the bound specified by the <Max NSLP Hops> parameter.
6.3 <Max NSLP Hops> Parameter
0 1 2 3 4 5 6 7
+-+-+-+-+-+-+-+-+
| Max NSLP Hops |
+-+-+-+-+-+-+-+-+
Max NSLP Hops: 8 bits
Indicates the maximum number of NSLP hops between the QNI and
QNR. Values of the composed parameter will range from 1 to 255,
limited by the bound on IP hop count. The default value of
<Max NSLP hops> is 255.
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6.4 <Excess Treatment> Parameter
0 1 2 3 4 5 6 7
+-+-+-+-+-+-+-+-+
| Excess |
| Treatment |
+-+-+-+-+-+-+-+-+
Excess Treatment: 8 bits
Indicates how the QNE SHOULD process out-of-profile traffic.
Allowed values are as follows:
0: drop
1: shape
2: remark
The excess treatment parameter is initially set by the QNI and
adjusted as needed by QNEs.
6.5 <Bandwidth> & <S> Parameters [RFC 2212, RFC 2215]
The <Bandwidth> parameter MUST be nonnegative and is measured in
bytes per second and has the same range and suggested representation
as the bucket and peak rates of the <Token Bucket>. <Bandwidth> can
be represented using single-precision IEEE floating point. The
representation MUST be able to express values ranging from 1 byte per
second to 40 terabytes per second. For values of this parameter only
valid non-negative floating point numbers are allowed. Negative
numbers (including "negative zero"), infinities, and NAN's are not
allowed.
A QNE MAY export a local value of zero for this parameter. A network
element or application receiving a composed value of zero for this
parameter MUST assume that the actual bandwidth available is unknown.
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Bandwidth (32-bit IEEE floating point number) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Slack Term [S] (32-bit integer) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Slack term S MUST be nonnegative and is measured in microseconds.
The Slack term, S, can be represented as a 32-bit integer. Its value
can range from 0 to (2**32)-1 microseconds.
6.6 <Token Bucket> Parameters [RFC 2215]
The <Token Bucket> parameters are represented by three floating
Point numbers in single-precision IEEE floating point format followed
by two 32-bit integers in network byte order. The first floating
point value is the rate (r), the second floating point value is the
bucket size (b), the third floating point is the peak rate (p), the
first integer is the minimum policed unit (m), and the second integer
is the maximum datagram size (M).
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+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Token Bucket Rate [r] (32-bit IEEE floating point number) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Token Bucket Size [b] (32-bit IEEE floating point number) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Peak Data Rate [p] (32-bit IEEE floating point number) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Minimum Policed Unit [m] (32-bit integer) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Maximum Packet Size [M] (32-bit integer) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
When r, b, p, and R terms are represented as IEEE floating point
values, the sign bit MUST be zero (all values MUST be non-negative).
Exponents less than 127 (i.e., 0) are prohibited. Exponents greater
than 162 (i.e., positive 35) are discouraged, except for specifying a
peak rate of infinity. Infinity is represented with an exponent of
all ones (255) and a sign bit and mantissa of all zeroes.
6.7 <QoS Class> Parameters
6.7.1 <PHB Class> Parameter [RFC 3170]
As prescribed in RFC 3170, the encoding for a single PHB is the
recommended DSCP value for that PHB, left-justified in the 16 bit
field, with bits 6 through 15 set to zero.
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+
| DSCP | 0 0 0 0 0 0 0 0 0 0 |
+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+
The registries needed to use RFC 3140 already exist, see [DSCP-
REGISTRY, PHBID-CODES-REGISTRY]. Hence, no new registry needs to be
created for this purpose.
6.7.2 <Y.1541 QoS Class> Parameter [Y.1541]
Y.1541 QoS classes are defined as follows:
0 1 2 3 4 5 6 7
+-+-+-+-+-+-+-+-+
| Y.1541 |
| QoS Class |
+-+-+-+-+-+-+-+-+
Y.1541 QoS Class: 8 bits
Indicates the Y.1541 QoS Class. Values currently allowed are 0,
1, 2, 3, 4, 5.
Class 0:
Mean delay <= 100 ms, delay variation <= 50 ms, loss ratio <= 10-3.
Real-time, highly interactive applications, sensitive to jitter.
Application examples include VoIP, Video Teleconference.
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Class 1:
Mean delay <= 400 ms, delay variation <= 50 ms, loss ratio <= 10-3.
Real-time, interactive applications, sensitive to jitter.
Application examples include VoIP, Video Teleconference.
Class 2:
Mean delay <= 100 ms, delay variation unspecified, loss ratio <=
10-3. Highly interactive transaction data. Application examples
include signaling.
Class 3:
Mean delay <= 400 ms, delay variation unspecified, loss ratio <=
10-3. Interactive transaction data. Application examples include
signaling.
Class 4:
Mean delay <= 1 sec, delay variation unspecified, loss ratio <= 10-3.
Low Loss Only applications. Application examples include short
transactions, bulk data, video streaming.
Class 5:
Mean delay unspecified, delay variation unspecified, loss ratio
unspecified. Unspecified applications. Application examples include
traditional applications of default IP networks.
6.7.3 <DSTE Class Type> Parameter [RFC3564]
DSTE class type is defined as follows:
0 1 2 3 4 5 6 7
+-+-+-+-+-+-+-+-+
| DSTE |
| Class Type |
+-+-+-+-+-+-+-+-+
DSTE Class Type: 8 bits
Indicates the DSTE class type. Values currently allowed are 0, 1,
2, 3, 4, 5, 6, 7.
6.8 Priority Parameters
6.8.1 <Preemption Priority> & <Defending Priority> Parameters
[RFC 3181]
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Preemption Priority | Defending Priority |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Preemption Priority: 16 bits (unsigned)
The priority of the new flow compared with the defending priority
of previously admitted flows. Higher values represent higher
priority.
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Defending Priority: 16 bits (unsigned)
6.8.2 <Reservation Priority> Parameter [SIP-PRIORITY]
0 1
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Reservation | Reservation |
| Priority | Priority |
| Namespace | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
High priority flows, normal priority flows, and best-effort priority
flows can have access to resources depending on their {"Namespace",
"Reservation Priority"} combination as follows:
Reservation Priority Namespace: 8 bits
0 - dsn high priority
1 - drsn high priority
2 - q735 high priority
3 - ets high priority
4 - wps high priority
5 - normal priority
6 - best-effort priority
Reservation Priority: 8 bits
Each namespace has a finite list of relative priority-values. Each
is listed here in the order of lowest priority to highest priority:
4 - dsn.routine
3 - dsn.priority
2 - dsn.immediate
1 - dsn.flash
0 - dsn.flash-override
5 - drsn.routine
4 - drsn.priority
3 - drsn.immediate
2 - drsn.flash
1 - drsn.flash-override
0 - drsn.flash-override-override
4 - q735.4
3 - q735.3
2 - q735.2
1 - q735.1
0 - q735.0
4 - ets.4
3 - ets.3
2 - ets.2
1 - ets.1
0 - ets.0
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4 - wps.4
3 - wps.3
2 - wps.2
1 - wps.1
0 - wps.0
0 - normal.0
0 - best.effort.0
Note that additional work is needed to communicate these flow
priority values to bearer-level network elements
[VERTICAL-INTERFACE].
6.9 <QoS Available> Parameters
6.9.1 <Path Latency> Parameter [RFC 2210, 2215]
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Path Latency (32-bit integer) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
The composition rule for the <Path Latency> parameter is summation
with a clamp of (2**32 - 1) on the maximum value. The latencies are
reported in units of one microsecond. An individual QNE can advertise
a latency value between 1 and 2**28 (somewhat over two minutes) and
the total latency added across all QNEs can range as high as
(2**32)-2. If the sum of the different elements delays exceeds
(2**32)-2, the end-to-end advertised delay SHOULD be reported as
indeterminate. The distinguished value (2**32)-1 is taken to mean
indeterminate latency. A QNE that cannot accurately predict the
latency of packets it is processing SHOULD set its local parameter
to this value. Because the composition function limits the composed
sum to this value, receipt of this value at a network element or
application indicates that the true path latency is not known. This
MAY happen because one or more network elements could not supply a
value, or because the range of the composition calculation was
exceeded.
6.9.2 <Path Jitter> Parameter
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Path Jitter (32-bit integer) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
The composition rule for the <Path Jitter> parameter is summation
with a clamp of (2**32 - 1) on the maximum value. The jitters are
reported in units of one microsecond. An individual QNE can advertise
a jitter value between 1 and 2**28 (somewhat over two minutes) and
the total jitter added across all QNEs can range as high as
(2**32)-2. If the sum of the different elements delays exceeds
(2**32)-2, the end-to-end advertised jitter SHOULD be reported as
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indeterminate. The distinguished value (2**32)-1 is taken to mean
indeterminate jitter. A QNE which cannot accurately predict the
jitter of packets it is processing SHOULD set its local parameter
to this value. Because the composition function limits the composed
sum to this value, receipt of this value at a network element or
application indicates that the true path jitter is not known. This
MAY happen because one or more network elements could not supply a
value, or because the range of the composition calculation was
exceeded.
6.9.3 <Path BER> Parameter
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Path Bit Error Rate (32-bit integer) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
The composition rule for the <Path BER> parameter is summation with
a clamp of 10^-2 on the maximum value. The BERs are reported in
units of 10^-11. An individual QNE can advertise a BER value between
1 and 2**28 and the total BER added across all QNEs can range as high
as (2**32)-2. If the sum of the different elements delays exceeds
(2**32)-2, the end-to-end advertised BER SHOULD be reported as
indeterminate. The distinguished value (2**32)-1 is taken to mean
indeterminate BER. A QNE which cannot accurately predict the BER of
packets it is processing SHOULD set its local parameter to this
value. Because the composition function limits the composed sum to
this value, receipt of this value at a network element or application
indicates that the true path BER is not known. This MAY happen
because one or more network elements could not supply a value, or
because the range of the composition calculation was exceeded.
6.9.4 <Ctot> <Dtot> <Csum> <Dsum> Parameters [RFC 2210, 2212, 2215]
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| End-to-end composed value for C [Ctot] (32-bit integer) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| End-to-end composed value for D [Dtot] (32-bit integer) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Since-last-reshaping point composed C [Csum] (32-bit integer) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Since-last-reshaping point composed D [Dsum] (32-bit integer) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
The error term C is measured in units of bytes. An individual QNE
can advertise a C value between 1 and 2**28 (a little over 250
megabytes) and the total added over all QNEs can range as high as
(2**32)-1. Should the sum of the different QNEs delay exceed
(2**32)-1, the end-to-end error term MUST be set to (2**32)-1. The
error term D is measured in units of one microsecond. An individual
QNE can advertise a delay value between 1 and 2**28 (somewhat over
two minutes) and the total delay added over all QNEs can range as
high as (2**32)-1. Should the sum of the different QNEs delay
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exceed (2**32)-1, the end-to-end delay MUST be set to (2**32)-1.
7. Security Considerations
The priority parameter raises possibilities for Theft of Service
Attacks because users could claim an emergency priority for their
flows without real need, thereby effectively preventing serious
emergency calls to get through. Several options exist for countering
such attacks, for example
- only some user groups (e.g. the police) are authorized to set the
emergency priority bit
- any user is authorized to employ the emergency priority bit for
particular destination addresses (e.g. police)
8. IANA Considerations
This section provides guidance to the Internet Assigned Numbers
Authority (IANA) regarding registration of values related to the
QSPEC template, in accordance with BCP 26 RFC 2434 [RFC2434].
[QoS-SIG] requires IANA to create a new registry for QoS Signaling
Policy Identifiers. The QoS Signaling Policy Identifier (QOSM ID) is
a 32 bit value carried in a QSPEC object. The allocation policy for
new QOSM IDs is TBD.
This document also defines 24 objects for the QSPEC Template, as
Detailed in Section 5. Values are to be assigned for them from the
GIMPS Object Type registry.
9. Acknowledgements
The authors would like to thank David Black, Robert Hancock, Dave
Oran, Tom Phelan, Hannes Tschofenig, and Sven van den Bosch, for
their very helpful suggestions.
10. 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.
The IETF invites any interested party to bring to its attention any
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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.
11. Normative References
[DSCP-REGISTRY] http://www.iana.org/assignments/dscp-registry
[PHBID-CODES-REGISTRY] http://www.iana.org/assignments/phbid-codes
[QoS-SIG] S. Van den Bosch et. al., "NSLP for Quality-of-Service
Signaling," work in progress.
[RFC2119] S. Bradner, "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC2205] B. Braden et. al., "Resource ReSerVation Protocol (RSVP)
-- Version 1 Functional Specification," RFC 2205, September 1997.
[RFC2210] J. Wroclawski, "The Use of RSVP with IETF Integrated
Services", RFC 2210, September 1997.
[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.
[RFC2475] S. Blake et. al., "An Architecture for Differentiated
Services", RFC 2475, December 1998.
12. Informative References
[CMSS] "PacketCable (TM) CMS to CMS Signaling Specification,
PKT-SP-CMSS-103-040402, April 2004.
[DIFFSERV-CLASS] Baker, F., et. al., "Configuration Guidelines
for DiffServ Service Classes," work in progress.
[INTSERV-QOSM] C. Kappler, "A QoS Model for Signaling IntServ
Controlled-Load Service with NSIS," work in progress.
[Q.2630] ITU-T Recommendation Q.2630.3: "AAL Type 2 Signaling
Protocol - Capability Set 3" Sep. 2003
[RFC1633] B. Braden et. al., "Integrated Services in the Internet
Architecture: an Overview," RFC 1633, June 1994.
[RFC3393] C. Demichelis, P. Chimento, "IP Packet Delay Variation
Metric for IP Performance Metrics (IPPM), RFC 3393, November 2002.
[RFC3564] F. Le Faucheur et. al., Requirements for Support of
Differentiated Services-aware MPLS Traffic Engineering, RFC 3564,
July 2003
[RFC3726] M. Brunner et. al., "Requirements for Signaling Protocols",
RFC 3726, April 2004.
[RMD-QOSM] A. Bader, L. Westberg, G. Karagiannis, C. Kappler and T.
Phelan, " RMD-QOSM: An NSIS QoS Signaling Policy Model for Networks
Using Resource Management in Diffserv (RMD)," work in progress.
[SIP-PRIORITY] H. Schulzrinne, J. Polk, "Communications Resource
Priority for the Session Initiation Protocol(SIP)." work in
progress.
[VERTICAL-INTERFACE] M. Dolly, P. S. Tarapore, S. Sayers,
"Discussion on Associating of Control Signaling Messages with Media
Priority Levels," T1S1.7 & PRQC, October 2004.
Ash, et. al. <draft-ietf-nsis-qspec-03.txt> [Page 22]
Internet Draft QoS-NSLP QSPEC Template February 2005
[Y.1541] ITU-T Recommendation Y.1541, "Network Performance
Objectives for IP-Based Services," May 2002.
[Y.1541-QOSM] J. Ash, et. al., "NSIS Network Service Layer Protocol
QoS Signaling Proof-of-Concept," work in progress.
13. 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
P.O. BOX 217
7500 AE Enschede
The Netherlands
EMail: g.karagiannis@ewi.utwente.nl
Ash, et. al. <draft-ietf-nsis-qspec-03.txt> [Page 23]
Internet Draft QoS-NSLP QSPEC Template February 2005
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 D1-33
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
QOSM needs to be defined.
A.1 QSPEC for Admission Control for DiffServ
QSPEC for Diffserv QOSM in general may be provided in future versions
of this draft. A QSPEC for a DiffServ QOSM is included in
[RMD-QOSM].
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 [RFC2210] and [RFC2215].
The QSPEC for IntServ Controlled Load is composed of the objects
<QoS Desired> and <QoS Available>, as well as <QoS Reserved>. Which
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 QOSM. Parameters in the QSPEC are as
follows:
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Internet Draft QoS-NSLP QSPEC Template February 2005
<QSPEC Control Information> = <NON NSLP Hop> <NSLP Hops>
<QoS Description> = <QoS Desired> <QoS Available> <QoS Reserved>
<QoS Desired> = <Token Bucket>
<QoS Available> = <Bandwidth> <Path Latency> <M>
<QoS Reserved> = <Token Bucket>
An IntServ over Diffserv QSPEC is
<QSPEC Control Information> = <NON NSLP Hop> <NSLP Hops>
<QoS Desired> = <Token Bucket>
<QoS Class> = <PHB Class>
<QoS Available> = <Bandwidth> <Path Latency> <M>
<QoS Reserved> = <Token Bucket>
Or a simple QSPEC for Diffserv requesting bandwidths for different
PHBs is
<QoS Desired> = <Bandwidth>
<QoS class> = <PHB Class>
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 guaranteed services is the following:
<QSPEC Control Information> = <NON NSLP Hop> <NSLP Hops>
<QoS Description> = <QoS Desired> <QoS Available> <QoS Reserved>
<QoS Desired> = <Token Bucket>
This object contains token bucket parameters defined in [RFC 2210].
(equivalent to TSpec defined in RSVP).
<QoS Available> = <Bandwidth> <Path Latency> <MTU> <Ctot> <Dtot>
<Csum> <Dsum>
These parameters are defined in [RFC 2212] and [RFC 2215]. This
object is equivalent to the AdSpec of RSVP.
<QoS Reserved> = <Token Bucket> <Bandwidth> <S>
Requested Rate and Slack Term defined in [RFC 2212], equivalent to
RSpec of RSVP.
Note that the Guaranteed Services QoS Model only works with receiver
initiated reservation signaling, because <Bandwidth> and <S> are
derived from parameters contained in <QoS Available>, and MAY be
updated on the return paths.
Appendix B: QoS Models and QSPECs
This Appendix gives a description of QoS Models 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
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Internet Draft QoS-NSLP QSPEC Template February 2005
will be removed.
QoS NSLP is a generic QoS signaling protocol that can signal for many
QOSMs. A QOSM is a particular QoS provisioning method or QoS
architecture such as IntServ Controlled Load or Guaranteed Service,
DiffServ, or RMD for DiffServ.
The definition of the QOSM is independent from the definition of QoS
NSLP. Existing QOSMs do not specify how to use QoS NSLP to signal
for them. Therefore, we need to define the QOSM specific signaling
functions, as [RMD-QOSM], [INTSERV-QOSM], and [Y.1541-QOSM].
A QOSM SHOULD include the following information:
- Role of QNEs in this QOSM:
E.g. location, frequency, statefulness...
- QSPEC Definition:
A QOSM SHOULD specify the QSPEC, including QSPEC parameters.
Furthermore it needs to explain how QSPEC parameters not used in this
QOSM 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
RMF and QOSM specific processing. E.g.
admission control, scheduling, policy control, QoS parameter
accumulation (e.g. delay).
- Operation and Sequence of Events
Usage of QoS-NSLP messages to signal the QOSM.
Appendix C: Mapping of QoS Desired, QoS Available and QoS Reserved of
NSIS onto AdSpec, TSpec and RSpec of RSVP IntServ
The union of QoS Desired, QoS Available and QoS Reserved 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
discussion at this point leads us to a slightly different mapping of
necessary functionality to objects, which should result in more
flexible signaling models.
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Full Copyright Statement
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This document and the information contained herein are provided on an
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OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY AND THE INTERNET
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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.
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.
Ash, et. al. <draft-ietf-nsis-qspec-03.txt> [Page 27]
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