TSVWG R. Geib, Ed.
Internet-Draft Deutsche Telekom
Intended status: Informational July 4, 2014
Expires: January 5, 2015
DiffServ interconnection classes and practice
draft-geib-tsvwg-diffserv-intercon-06
Abstract
This document proposes a limited and well defined set of QoS PHBs and
PHB groups to be applied at (inter)connections of two separately
administered and operated networks. Many network providers operate
Treatment Aggregate of different DiffServ classes. This draft offers
a simple and constrained interconnection concept which may simplify
operation and negotiation of DiffServ at interconnection points.
Status of this Memo
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This Internet-Draft will expire on January 5, 2015.
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described in the Simplified BSD License.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.1. Related work . . . . . . . . . . . . . . . . . . . . . . . 5
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 5
3. An Interconnection class and codepoint scheme . . . . . . . . 5
3.1. Limitations arising from the MPLS Short Pipe model . . . . 9
3.2. Treatment of Network Control traffic at carrier
interconnection interfaces . . . . . . . . . . . . . . . . 9
4. DiffServ Intercon relation to other QoS standards
(revision may be required) . . . . . . . . . . . . . . . . . . 10
4.1. MPLS, Ethernet and DSCP Precedence Prefixes for
aggregated classes . . . . . . . . . . . . . . . . . . . . 11
4.2. Proposed GSMA IR.34 to DiffServ Intercon mapping . . . . . 11
4.3. Proposed MEF 23.1 to DiffServ Intercon mapping . . . . . . 12
5. Contributors . . . . . . . . . . . . . . . . . . . . . . . . . 13
6. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 14
7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 14
8. Security Considerations . . . . . . . . . . . . . . . . . . . 14
9. References . . . . . . . . . . . . . . . . . . . . . . . . . . 14
9.1. Normative References . . . . . . . . . . . . . . . . . . . 14
9.2. Informative References . . . . . . . . . . . . . . . . . . 15
Appendix A. Change log . . . . . . . . . . . . . . . . . . . . . 16
Author's Address . . . . . . . . . . . . . . . . . . . . . . . . . 16
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1. Introduction
DiffServ has been deployed in many networks. As described by section
2.3.4.2 of RFC 2475, remarking of packets at domain boundaries is a
DiffServ feature [RFC2475]. This draft proposes a set of standard
QoS classes and code points at interconnection points to which and
from which locally used classes and code points should be mapped.
Many providers operate MPLS based backbones. RFC 5127 assumes
backbone engineering to ensure that a major link, switch, or router
can fail, and the result will be a routed network that still meets
ambient Service Level Agreements classes(SLAs) [RFC5127]. Based on
it, RFC5127 introduces the concept of Treatment Aggregates, which
allow to forward multiple DSCPs by a single MPLS Traffic Class. This
draft shares the assumption of RFC 5127 on backbone engineering.
RFC3270 adds the Short Pipe Models to the Pipe and Uniform Model
already defined for Differentiated Services and Tunnels [RFC2983] ,
[RFC3270]. It was required due to the presence of Pen-ultimate hop
popping (PHP) of MPLS Labels. RFC3270 expects the Short Pipe model
only to be deployed for IP tunnels and VPNs. If it used to transport
non tunneled IP traffic, some restrictions may apply for DSCP
transparency. The Short Pipe model is popular with many network
providers operating MPLS.
RFC2474 specifies the DiffServ Codepoint Field [RFC2474].
Differentiated treatment is based on the specific DSCP. Once set, it
may change, but any DSCP rewrite is always a one by one mapping.
What is not allowed is remarking n received DSCPs to a single
transmitted DSCP. If unknown DSCPs are received, RFC2474 recommends
transmitting them unchanged by default forwarding. An MPLS network
supporting the Short Pipe model for not tunneled IPv4 traffic may
need to be able to correctly classify or rewrite the IP DSCP on
interfaces between the last Label Switch Router and a Label Edge
Router. In that case, it may not be possible to transmit 64 DSCPs
through this domain.
RFC5127 proposes to transmit DSCPs as they are received in general.
This is not possible, if the receiving and the transmitting domain
use different DSCPs for the PHBs to which traffic is mapped if both
interconnect.
This draft adresses IP interconnection supporting DiffServ to or
between providers operating MPLS in their backbone. It proposes
operational simplifications and methods to match IP DiffServ
requirements with MPLS limitations (especially regarding the Short
Pipe Model if applied for non tunnel IPv4 traffic). The scope of
this draft is limited to 4 specified interconnection Treatment
Aggregates. To ease operation and to ensure traffic to leave a
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domain with the DSCPs received, small sets of specific DSCPs and a
definition of their Treatment Aggregate PHB are suggested. The
mechanism proposed here may be extended. This is relevant only if it
sees some deployment, and it is preferred to start with a limited and
simple approach to clarify the concept.
At first glance, the interconnection codepoint scheme may look like
an additional effort. But there are some obvious benefits: each
party sending or receiving traffic has to specify the mapping from or
to the interconnection class and code point scheme only once.
Without it, this is to be negotiated per interconnection party
individually. Further, end-to-end QoS in terms of traffic being
classified for say, for a sufficiently similar PHB in all passed
domains is more likely to result if an interconnection code point
scheme is used. This draft supports a remarking of one DSCP only to
one other DSCPs (no n DSCP to one DSCP remarking).
The example given in RFC 5127 on aggregation of DiffServ service
classes picks 4 Treatment Aggregates. This draft also favours 4
Treatment Aggregates. Reasons to favour working with 4 DiffServ
Treatment Aggregates:
o There should be a coding reserve for interconnection classes.
This leaves space for future standards, for private bilateral
agreements and for provider internal classes.
o The fields available for carrying QoS information (e.g., DiffServ
PHB) in MPLS and Ethernet are only 3 bits in size, and are
intended for more than just QoS purposes (see e.g. [RFC5129]).
o Migrations from one code point scheme to another may require spare
QoS code points.
RFC5127 provides recommendations on aggregation of IP DSCPs into MPLS
Treatment Aggregates and offers a deployment example [RFC5127].
RFC5127 seems to be based on an assumption the the MPLS Short Pipe
model is only deployed for tunneled IP products or VPNs. This draft
assumes presence of non tunneled IPv4 traffic and deployment of the
MPLS Short Pipe model. That requires deviating from the RFC5127
example as follows:
o DSCP remarking is to be expected at provider edges, if the domain
is terminating this traffic.
o This draft follows RFC4594 in the proposed marking of provider
Network Control traffic and expands RFC4594 on treatment of CS6
marked traffic at interconnection points (see section 5.2).
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The proposed Interconnection class and code point scheme tries to
reflect and consolidate related DiffServ and QoS standardisation
efforts outside of the IETF, namely MEF [MEF 23.1], GSMA [IR.34] and
ITU [Y.1566]. GSMAs IR.34 specifies an inter provider VPN, but it is
nevertheless specifying a kind of DiffServ aware IP based carrier
interconnection.
1.1. Related work
In addition to the standardisation activities which triggered this
work, other authors published RFCs or drafts which may benefit from
an interconnection class- and codepoint scheme. RFC 5160 suggests
Meta-QoS- Classes to enable deployment of standardised end to end QoS
classes [RFC5160]. The authors agree that the proposed
interconnection class- and codepoint scheme as well as the idea of
standardised end to end classes would complement their own work.
Work on signaling Class of Service at interconnection interfaces by
BGP [I-D.knoll-idr-cos-interconnect], [ID.idr-sla] is beyond the
scope of this draft. Should the basic transport and class properties
be standardised as proposed here, signaled access to QoS classes may
be of interest. The current BGP drafts focus on exchanging SLA and
traffic conditioning parameters. They seem to assume that common
interpretation of the PHB properties identified by DSCPs has been
established prior to exchanging further details by BGP signaling.
2. Terminology
This draft reuses existing terminology of RFCs 2474 and 5127.
3. An Interconnection class and codepoint scheme
Interconnecting parties face the problem of matching classes to be
interconnected and then to agree on code point mapping. As stated by
the DiffServ Architecture [RFC2475], remarking is a standard
behaviour at interconnection interfaces. If the MPLS Short Pipe
model is deployed by the receiving domain, the Label Switch Router
prior to and the destination Label Edge Router may have to correctly
classify traffic by its DSCP. To avoid DSCPs being misused, only
domain internal DSCPs may be tolerated there. This means, that
traffic terminating within this domain will be delivered with the
DSCP matching the properties of the PHB at interconnection, but with
the DSCP assigned by the terminating domain. This draft proposes a
standard interconnection set of 4 Treatment Aggregates with well
defined DSCPs to be aggregated by them. A sending party remarks
DSCPs from internal schemes to the Interconnection code points. The
receiving party remarks DSCPs to her internal scheme. The
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interconnection code point scheme fully complies with the DiffServ
architecture. DiffServ compliance does not allow for a rewrite of
several received DSCPs with a single DSCP to be transmitted. The set
of DSCPs and PHBs supported accross the two interconnected domains
and the treatment of PHBs and DSCPs not recognised by any of both
domains should be part of an SLA. DiffServ transit to a third party
network is excluded for initial versions of this draft (but may be
added if there's interest).
This draft picks up the DiffServ interconnection class defintions
proposed by ITU-T Y.1566 [Y.1566]. The classes defined there, are
used as MPLS Treatment Aggregates here. This draft proposes a set of
Treatment Aggregate PHBs and DSCPs to be aggregated. Their
properties differ slightly from those of the RFC5127 example:
Class Priority: PHB EF, DSCP 101 110. The figures of merit
describing the PHB to be in the range of low single digit
milliseconds. See [RFC3246]. This class corresponds to RFC
5127's real time class, but it is limited to traffic for
which node configuration "ensures that the service rate of EF
packets on a given output interface exceeds their arrival
rate at that interface over long and short time intervals"
(see RFC 3246).
Bulk inelastic: The Treatment Aggregate is initially designed only
to transport PHB AF41, DSCP 100 010 (the other AF4 PHB group
PHB's and DSCPs should be reserved for future extension of
the set of DSCPs carried by this Treatment Aggregate).
Optimised for low loss, low delay, low jitter at high
bandwidth. Traffic load in this class must be controlled,
e.g. by application servers. One example could be flow
admission control. There may be infrequent retransmissions
requested by the application layer to mitigate low levels of
packet losses. Discard of packets through active queue
management should be avoided in this class. Congestion in
this class may result in bursty packet loss. If used to
carry multimedia traffic, it is recommended to carry audio
and video traffic in a single PHB (note that video
conferencing may require separate PHBs for audio and video
traffic, which could also be realised by utilising two AF 4
PHBs). All of these properties influence the buffer design.
This class is designed to transport those parts of RFC 5127's
Real Time class, which consume considerable QoS bandwidth at
the interconnection interface.
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Assured: The complete PHB group AF3, DSCPs 011 010, 011 100 and 011
110 is transmitted by this Treatment Aggregate. It may be
optimised to transport traffic without bandwidth
requirements. It aims on very low loss at high bandwidths.
Retransmissions after losses characterise the class and
influence the buffer design. Active queue management with
probabilistic dropping may be deployed. The RFC 5127 example
calls this class Assured Elastic.
Default: The Treatment Aggregate for the default PHB, CS0 with DSCP
000 000. This class may be optimised to transport traffic
without bandwidth requirements. Retransmissions after losses
characterise the class and influence the buffer design.
Active queue management with probabilistic dropping may be
deployed. The RFC 5127 example calls this class Elastic.
RFC2474 recommends leaving DSCPs unknown to a receiving domain
unchanged while default PHB transport is provided. If there's
community interest in this draft, current carrier deployments should
be checked for support of this RFC2474 recommendation.
The idea is illustrated by an example. Provider O and provider W are
peer with provider T. They have agreed upon a QoS interconnection.
Traffic of provider O terminates within provider Ts network, while
the GSMA IR.34 traffic transits through the netwirk of provider T to
provider F. Assume all providers to run their own internal codepoint
schemes for a class with properties of the DiffServ Intercon Assured
Treatment Aggregate. See below for a description of GSMA IR.34.
Provider-O Provider-W
RFC5127 GSMA 34.1
| |
+----------+ +----------+
|AF21, AF22| |AF31, AF21|
+----------+ +----------+
| |
V V
+++++++++ +++++++++
|Rtr PrO| |Rtr PrW|
+++++++++ +++++++++
| DiffServ |
+----------+ +----------+
|AF31, AF32| |AF31, AF32|
+----------+ +----------+
| Intercon |
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V V
+++++++++ |
|RtrPrTI|------------------+
+++++++++
| Provider-T domain
+-----------+
| MPLS TC 2 |
| DSCP rew. |
| AF21, AF22|
+-----------+
| | Local DSCPs Provider-T
| | +----------+ +++++++++
V +->|AF21, AF22|->-|RtrDstH|
| +----------+ +++++++++
+----------+
|AF21, AF22|
+----------+
|
+++++++++
|RtrPrTE|
+++++++++
| DiffServ
+----------+
|AF31, AF32|
+----------+
| Intercon
+++++++++
|RtrPrHF|
+++++++++
|
+----------+
|AF31, AF21|
+----------+
|
Provider-F
GSM IR.34
DiffServ Intercon example
Figure 1
It is easily visible that all providers only need to deploy internal
DSCP to DiffServ Intercon DSCP mappings to exchange traffic in the
desired classes.
RFC5127 specifies a separate Treatment Aggregate for network control
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traffic. It may be present at interconnection interfaces too, but
depending on the agreement between providers, Network Control traffic
may also be classified for another interconnection class. See below
for a detailed discussion on the treatment of Network Control
traffic.
The proposed class and code point scheme is designed for point to
point IP layer interconnections. Other types of interconnections are
out of scope of this document. The basic class and code point scheme
is applicable on Ethernet layer too.
3.1. Limitations arising from the MPLS Short Pipe model
If non tunneled IPv4 traffic is transmitted by deploying the MPLS
Short Pipe model as specified by RFC3270, then IP DSCPs may be used
for classification or they may be remarked at interfaces between the
destination Label Edge Router and the Label Switch Router. Domain
internal Treatment Aggregates may be applicable, e.g. for domain
internal network control traffic. This Treatment Aggregate and the
DSCPs which are aggregated by it, may not be available for customer
traffic. A domain supporting such an internal Treatment Aggregate
can't support a set of 64 DSCPs in that case. As mentioned below,
the number of PHBs and their DSCPs supported end-to-end should be as
well defined as the treatment of not recognised DSCPs when
negotiating interconnection.
The situation is more relaxed for tunneled IPv4 traffic, IPv6 traffic
in general (for the time being) and for VPN traffic. If there's
community interest, a later version of this discuss this in more
detail.
3.2. Treatment of Network Control traffic at carrier interconnection
interfaces
As specified by RFC4594, section 3.2, Network Control (NC) traffic
marked by CS6 is to be expected at interconnection interfaces. This
document does not change NC specifications of RFC4594. The latter
specification is detailed on domain internal NC traffic and on
traffic exchanged between peering points. Further, it recommends not
to forward CS6 marked traffic originating from user-controlled end
points by the NC class of a provider domain.
As a minor clarification to RFC4594, "peering" shouldn't be
interpreted in a commercial sense. The NC PHB is applicable also in
the case of a purchased network service based on a transit agreement
with an upstream provider. RFC4594 recommendations on NC traffic are
applicable for IP carrier interconnections in general.
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Some CS6 traffic exchanged accross carrier interconnections will
terminate at the domain ingress node (e.g., if BGP is running between
the two routers on opposite ends of the interconnection link).
If the MPLS Short Pipe model is deployed for non tunneled IPv4
traffic, an IP carrier may limit access to the NC PHB for traffic
which is recognised as network control traffic relevant to the own
domain. Interconnecting carriers should specify treatment of CS6
marked traffic received at a carrier interconnection which is to be
forwarded beyond the ingress node. An SLA covering the following
cases is recommended, if a carrier wishes to send CS6 marked traffic
accross an interconnection link which isn't terminating at the
interconnected ingress node:
o classification of traffic which is network control traffic for
both domains. This traffic should be classified and marked for
the NC PHB.
o classification of traffic which is network control traffic for the
sending domain only. This traffic should be classified for a PHB
offering similar properties as the NC class (e.g. AF31 as
specified by this document). As an example GSMA IR.34 proposes an
Interactive class / AF31 to carry SIP and DIAMETER traffic. While
this is service control traffic of high importance to the
interconnected Mobile Network Operators, it is certainly no
Network Control traffic for a fixed network providing transit.
The example may not be perfect. It was picked nevertheless
because it refers to an existing standard.
o any other CS6 marked traffic should be remarked or dropped.
4. DiffServ Intercon relation to other QoS standards (revision may be
required)
This sections provides suggestions how to aggregate traffic by DSCP
Precedence Prefexies to Ethernet and MPLS. Other Standardisation
Organsiations deal with QoS aware provider interconnection. As IP is
the state of the art realisation of provider interconnections, these
standards bodies specify DiffServ aware interconnections. Some of
these bodies are industry alliances chartered also to promote
interconnection of wireless or Ethernet technology including the
exchange of IP datagrams at interconnection points. Examples are the
Metro Ethernet Forum (MEF) or the GSM Alliance (GSMA). The ITU was
mentioned earlier. ITU works across and between responsibilities of
different Standardisation Organisations and liaising with them, if
their responsibilities are touched, is traditional part of that
process.
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4.1. MPLS, Ethernet and DSCP Precedence Prefixes for aggregated classes
The interconnection class and code point scheme respects properties
and limits of a 3 bit PHB coding space in different ways:
o it allows to classify four interconnection classes based on the
DSCP Precedence Prefix.
o it supports a single PHB group (AF3), whose DSCPs may be
aggregated into a sinle MPLS TC (or Ethernet priority) based on
their joint DSCP Precedence Prefix. This kind of aggregation will
work for the AF4 PHB group, if the PHBs AF42 and AF43 need to be
supported in addition to AF41.
o Applying only 4 aggregated classes at interconnection allows for
bilateral extensions, if desired. Should two carriers agree to
map AF32 and AF33 to an additional individual MPLS TC and offer an
Ordered Aggregate across the interconnecting domain, this proposal
at leaves some MPLS TC coding space for such an extension
(although this draft doesn't recommend interconnections of that
type).
The above statement is no requirement to depricate any DSCP to MPLS
TC or Ethernet P-Bit mapping functionality. In the opposite, by
limiting the interconnection scheme to 6 PHBs, each PHB may be mapped
to an individual Traffic Class or Priority also within MPLS or
Ethernet (if desired).
4.2. Proposed GSMA IR.34 to DiffServ Intercon mapping
GSMA IR.34 provides guidelines on how to set up and interconnect
Internet Protocol (IP) Packet eXchange (IPX) Networks [IR.34]. An
IPX network is an inter-Service Provider IP backbone which comprises
the interconnected networks of IPX Providers. IPX is a
telecommunications interconnection model for the exchange of IP based
traffic between customers of separate mobile and fixed operators as
well as other types of service provider (such as ISP), via IP based
network-to-network interface. Note that IPX is not a public
interconnection model however, it is designed as a private IP
Backbone of the interconnected parties. Two IPX partners may
interconnect using transit offered by an Inter-Service Provider IP
Backbone. This requires an IP QoS aware interconnection as described
by this draft between IPX provider and Inter-Service Provider IP
Backbone.
GSMA IR.34 specifies 4 aggregated classes and 7 PHBs. Mapping to
DiffServ Intercon is smooth apart from the GSMA aggregated class
Interactive, which consistfs of 4 PHBs. The table below lists a
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suggested mapping to DiffServ Intercon.
| GSMA IR.34 | DiffServ-Intercon |
| | |
| Agg. Class | PHB | Agg. Class | PHB |
+---------------+-------+--------------+--------+
|Conversational | EF | Priority | EF |
+---------------+-------+--------------+--------+
| Streaming | AF41 |Bulk inelastic| AF41 |
+---------------+-------+--------------+--------+
| Interactive | AF31 | Assured | AF31 |
+ +-------+ +--------+
| (ordered by | AF32 | | |
+ priority, +-------+ + AF32 +
| AF3 highest) | AF21 | | |
+ +-------+ +--------+
| | AF11 | | AF33 |
+---------------+-------+--------------+--------+
| Background | CS0 | Default | CS0 |
+---------------+-------+--------------+--------+
Suggested mapping of GSMA IR.34 classes and PHBs to DiffServ Intercon
Figure 2
The motivation resulting in the design of the IR.34 Intercative class
are unknown to the author of this draft. It is out of scope of this
draft to decide how 4 PHBs can be mapped to a to single aggregated
class. The suggested mapping is pragmatic and tries to come as close
as possible to other design criteria pursued by GSMA IR.34.
4.3. Proposed MEF 23.1 to DiffServ Intercon mapping
MEF 23.1 is an implemenation agreement facilitating Ethernet service
interoperability and consistency between Operators and the use of a
common CoS Label set for Subscribers [MEF23.1]. It pursues the same
aims and method on Ethernet layer as this draft does on IP layer
(i.e. providing an interconnection class and codepoint scheme). MEF
23.1 addresses external network to network interfaces typically
interconnecting metro ethernet providers. This may typically involve
Ethernet Network Sections associated with typical Operator domains
that interconnect at external network to network interfaces. MEF
23.1 specifies three aggregated CoS classes. In addition, the usage
of a subset of Ethernet PCP and IP DSCP values is specifiedthus
facilitating synergies between Ethernet and IP services and networks.
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The main purpose is specifying operator virtual (Ethernet)
connections. As an IP QoS model is added, this draft proposes an IP
class and codepoint mapping.
MEF 23.1 QoS mapping requires some thought as 3 classes are supported
of which two are Ordered Aggregates. MEF 23.1s section 8.5.1 example
on IP DSCP mapping may suggest supporting classification based on the
DSCP Precedence Prefix. MEF 23.1 section 8.5.2.1 allows the
conclusion that MEF class M is best mapped to this drafts Bulk
inelastic class. The suggested mapping MEF to DiffServ Intercon is
limited to the the MEF color blind mode (3 classes, no sub-classes):
| MEF 23.1 | DiffServ-Intercon |
| | |
| Agg. Class | PHB | Agg. Class | PHB |
+---------------+-------+--------------+--------+
| High | EF | Priority | EF |
+---------------+-------+--------------+--------+
| Medium | AF3 |Bulk inelastic| AF41 |
+---------------+-------+--------------+--------+
| Low | CS1 | Default | CS0 |
+---------------+-------+--------------+--------+
Suggested mapping of MEF 23.1 color blind mode classes and PHBs to
DiffServ Intercon
Figure 3
The MEF color aware mode supports Ordered Aggregates in the MEF
classes M and L. The MEF L specification classifies AF1 and Best
Effort for the same Ordered Aggregate. A Better than Best Effort
service produced in the same queue as best effort traffic can be
realized, but hasn't been standardized by IETF. This document
doesn't suggest any mapping. Diffserv Intercon also doesn't suggest
an Ordered Aggregate in the Bulk Inelastic class. Later versions of
this document may do so and specify a solution. Both issues are left
for bilateral negotiation.
5. Contributors
David Black provided many helpful comments and inputs to this work.
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6. Acknowledgements
Al Morton and Sebastien Jobert provided feedback on many aspects
during private discussions. Mohamed Boucadair and Thomas Knoll
helped adding awareness of related work. David Black, Fred Baker and
Brian Carpenter provided intensive feedback and discussion.
7. IANA Considerations
This memo includes no request to IANA.
8. Security Considerations
This document does not introduce new features, it describes how to
use existing ones. The security section of RFC 2475 [RFC2475] and
RFC 4594 [RFC4594] apply.
9. References
9.1. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC2474] Nichols, K., Blake, S., Baker, F., and D. Black,
"Definition of the Differentiated Services Field (DS
Field) in the IPv4 and IPv6 Headers", RFC 2474,
December 1998.
[RFC2475] Blake, S., Black, D., Carlson, M., Davies, E., Wang, Z.,
and W. Weiss, "An Architecture for Differentiated
Services", RFC 2475, December 1998.
[RFC2597] Heinanen, J., Baker, F., Weiss, W., and J. Wroclawski,
"Assured Forwarding PHB Group", RFC 2597, June 1999.
[RFC3246] Davie, B., Charny, A., Bennet, J., Benson, K., Le Boudec,
J., Courtney, W., Davari, S., Firoiu, V., and D.
Stiliadis, "An Expedited Forwarding PHB (Per-Hop
Behavior)", RFC 3246, March 2002.
[RFC3260] Grossman, D., "New Terminology and Clarifications for
Diffserv", RFC 3260, April 2002.
[RFC3270] Le Faucheur, F., Wu, L., Davie, B., Davari, S., Vaananen,
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P., Krishnan, R., Cheval, P., and J. Heinanen, "Multi-
Protocol Label Switching (MPLS) Support of Differentiated
Services", RFC 3270, May 2002.
[RFC5129] Davie, B., Briscoe, B., and J. Tay, "Explicit Congestion
Marking in MPLS", RFC 5129, January 2008.
[RFC5462] Andersson, L. and R. Asati, "Multiprotocol Label Switching
(MPLS) Label Stack Entry: "EXP" Field Renamed to "Traffic
Class" Field", RFC 5462, February 2009.
[min_ref] authSurName, authInitials., "Minimal Reference", 2006.
9.2. Informative References
[I-D.knoll-idr-cos-interconnect]
Knoll, T., "BGP Class of Service Interconnection",
draft-knoll-idr-cos-interconnect-12 (work in progress),
May 2014.
[ID.idr-sla]
IETF, "Inter-domain SLA Exchange", IETF, http://
datatracker.ietf.org/doc/draft-ietf-idr-sla-exchange/,
2013.
[IEEE802.1Q]
IEEE, "IEEE Standard for Local and Metropolitan Area
Networks - Virtual Bridged Local Area Networks", 2005.
[IR.34] GSMA Association, "IR.34 Inter-Service Provider IP
Backbone Guidelines Version 7.0", GSMA, GSMA IR.34 http:/
/www.gsma.com/newsroom/wp-content/uploads/2012/03/
ir.34.pdf, 2012.
[MEF23.1] MEF, "Implementation Agreement MEF 23.1 Carrier Ethernet
Class of Service Phase 2", MEF, MEF23.1 http://
metroethernetforum.org/PDF_Documents/
technical-specifications/MEF_23.1.pdf, 2012.
[RFC2983] Black, D., "Differentiated Services and Tunnels",
RFC 2983, October 2000.
[RFC4594] Babiarz, J., Chan, K., and F. Baker, "Configuration
Guidelines for DiffServ Service Classes", RFC 4594,
August 2006.
[RFC5127] Chan, K., Babiarz, J., and F. Baker, "Aggregation of
Diffserv Service Classes", RFC 5127, February 2008.
Geib Expires January 5, 2015 [Page 15]
Internet-Draft Abbreviated Title July 2014
[RFC5160] Levis, P. and M. Boucadair, "Considerations of Provider-
to-Provider Agreements for Internet-Scale Quality of
Service (QoS)", RFC 5160, March 2008.
[Y.1566] ITU-T, "Quality of service mapping and interconnection
between Ethernet, IP and multiprotocol label switching
networks", ITU,
http://www.itu.int/rec/T-REC-Y.1566-201207-I/en, 2012.
Appendix A. Change log
00 to 01 Added terminology and references. Added details and
information to interconnection class and codepoint scheme.
Editorial changes.
01 to 02 Added some references regarding related work. Clarified
class definitions. Further editorial improvements.
02 to 03 Consistent terminology. Discussion of Network Management
PHB at interconnection interfaces. Editorial review.
03 to 04 Again improved terminology. Better wording of Network
Control PHB at interconnection interfaces.
04 to 05 Large rewrite and re-ordering of contents.
05 to 06 Description of IP and MPLS related requirements and
constraints on DSCP rewrites.
Author's Address
Ruediger Geib (editor)
Deutsche Telekom
Heinrich Hertz Str. 3-7
Darmstadt, 64295
Germany
Phone: +49 6151 5812747
Email: Ruediger.Geib@telekom.de
Geib Expires January 5, 2015 [Page 16]
