Francois Le Faucheur, Editor
Thomas Nadeau
Cisco Systems, Inc.
Martin Tatham
BT
Thomas Telkamp
David Cooper
Global Crossing
Jim Boyle
Luca Martini
Level 3 Communications, LLC
Luyuan Fang
Waisum Lai
Jerry Ash
AT&T
Pete Hicks
Core Express
Angela Chiu
Celion Networks
William Townsend
Tenor Networks
Darek Skalecki
Nortel Networks
IETF Internet Draft
Expires: November, 2001
Document: draft-ietf-tewg-diff-te-reqts-01.txt June, 2001
Requirements for support of
Diff-Serv-aware MPLS Traffic Engineering
Status of this Memo
This document is an Internet-Draft and is in full conformance with
all provisions of Section 10 of RFC2026. Internet-Drafts are
Working documents of the Internet Engineering Task Force (IETF), its
areas, and its working groups. Note that other groups may also
distribute working documents as Internet-Drafts.
Internet-Drafts are draft documents valid for a maximum of six
months and may be updated, replaced, or obsoleted by other documents
Le Faucheur, et. al 1
Requirements for Diff-Serv Traffic Engineering June 2001
at any time. It is inappropriate to use Internet-Drafts as reference
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http://www.ietf.org/ietf/1id-abstracts.txt.
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Abstract
This document presents the Service Provider requirements for support
of Diff-Serv aware MPLS Traffic Engineering (DS-TE) as discussed in
the Traffic Engineering Working Group Framework document [TEWG-FW].
1. Problem Statement
Diff-Serv is becoming prominent in providing scalable multi-class of
services in IP networks.
In some Diff-Serv networks where optimization of transmission
resources on a network-wide basis is not sought, MPLS Traffic
Engineering mechanisms may simply not be used in complement to Diff-
Serv mechanisms.
In other networks, where some optimization of transmission resources
is sought, Diff-Serv mechanisms ([DIFF-MPLS]) may be complemented by
existing MPLS Traffic Engineering mechanisms ([TE-REQ], [ISIS-TE],
[OSPF-TE], [RSVP-TE], [CR-LDP]) which operate on an aggregate basis
across all Diff-Serv Behavior Aggregates. In that case, Diff-Serv
and MPLS TE both provides their respective benefits (i.e. Diff-Serv
performs service differentiation at every hop, Traffic Engineering
achieves better distribution of the aggregate traffic load across
the set of network resources). However, they operate independently
of each other. In other words, MPLS Traffic Engineering performs
Constraint Based Routing and Admission Control with the same set of
global constraints for all Behavior Aggregates and without the
ability to use different sets of constraints for different Behavior
Aggregates.
In yet other networks where fine optimization of transmission
resources is sought, it may be beneficial to perform traffic
engineering at a per-class level instead of an aggregate level, in
order to further enhance networks in performance and efficiency as
discussed in [TEWG-FW]. By mapping a traffic trunk in a given class
on a separate LSP, it allows the traffic trunk to utilize resources
available to the given class on both shortest path(s) and non-
shortest paths and follow paths that meet constraints which are
specific to the given class. This is what we refer to as "Diff-Serv-
aware Traffic Engineering (DS-TE)".
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Requirements for Diff-Serv Traffic Engineering June 2001
This document focuses exclusively on the specific environments which
would benefit from DS-TE. In preview, networks where bandwidth is
scarce (e.g. transcontinental networks), where high priority traffic
can be significant compared to link speed on some links (e.g.
service provider networks with very large voice trunks), and where
the relative proportion of traffic across Behavior Aggregates is not
uniform across the whole topology are examples of networks where
Diff-Serv-aware Traffic Engineering may yield significant benefits.
This document focuses on intra-domain operations. Inter-domain
operations is not considered.
Below are examples of specific scenarios where Service Providers
require DS-TE.
1.1. Scenario 1: High Proportion of Voice
An IP/MPLS network may need to carry a significant amount of VoIP
(EF) traffic, compared to its link capacities. For example, 10,000
uncompressed calls at 20ms packetization result in about 1Gbps of IP
traffic, which is already significant on an OC-48c based network. In
case of topology changes such as link/node failure, EF traffic
levels can even approach the link bandwidths.
For delay/jitter reasons it is undesirable to carry more than a
certain percentage of EF traffic on any link. The rest of the
available link bandwidth can be used to route other classes
corresponding to delay/jitter insensitive traffic (e.g. Best Effort
Internet traffic). The exact determination of this percentage is
outside the scope of this requirements draft.
During normal operations, the VoIP traffic should be able to preempt
other classes of traffic (if these other classes are designated as
preemptable and they have lower preemption priority),
so that it will be able to use the shortest available path, only
constrained by the maximum defined VoIP link utilization
ratio/percentage.
Existing TE mechanisms only allow to do constraint based routing of
traffic based on a single bandwidth constraint common to all
classes, which does not satisfy the needs described here.
1.2. Scenario 2: Rerouting on Lower Speed facilities
An IP/MPLS network may support multiple classes of traffic. Assume
that a network topology includes OC48/192s links including {Chicago
to New York, New York to Washington DC, Washington DC to Dallas and
Dallas to Chicago} and some OC3/12s links along {Chicago to
Cleveland, Cleveland to Philadelphia, Philadelphia to New York}.
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Requirements for Diff-Serv Traffic Engineering June 2001
Assume also, as in previous scenario, that one (or more) high
priority class(es) of service has tight quality requirements which
could not be met if there was more traffic of this class on a link
than a "moderate" percentage of the link.
The OC48/192s and OC3/12s links may have been provisioned so that,
in steady state, there will be less high priority traffic than the
desired "moderate" percentage. For instance, the amount of high
priority traffic may be "relatively" small so that, in steady state,
the network administrator knows that it will never exceed 25 % of
any link capacity, without having to enforce this via separate
constraint based routing or Admission Control. To provide the
appropriate level of quality to each class of service, the network
administrator only needs to configure the Diff-Serv PHBs (scheduler
queues) appropriately.
However, under failure of some links, the remaining links may not
always be sufficient to ensure that after rerouting, high priority
traffic does not exceed the "moderate" percentage on all the links.
Consider a failure scenario in the topology above where the Chicago
to New York link is down while there is no failure of the OC3/12
links. As traffic is rerouted, it is possible that the jitter
sensitive high priority traffic will exceed the desired percentage
of link capacity of the links along the shorter, but lower capacity
routes. In our scenario, the "relatively small" amount of high
priority traffic of 25% worth of OC48/192s may turn into "excessive"
amount of high priority traffic on the OC3/12 links.
Current TE mechanisms allow high priority traffic to be rerouted
separately from the other classes of traffic (i.e. by building
separate TE-LSPs for high priority and for other classes). However,
current mechanisms only allow route computation to enforce a common
bandwidth constraint. Assuming that the network administrator elects
to give higher preemption priority to the high priority traffic (in
order to maximize its chances of being rerouted and also maximize
its chances of being rerouted on its shortest path), this may result
in high priority tunnels routed onto the OC3/12 links up to the full
capacity of the link. This would result in unacceptable degradation
of quality of the high priority traffic.
This leads to the requirement for DS-TE to be able to enforce a
different bandwidth constraint for different classes of traffic. In
the above example, the bandwidth constraint to be enforced for high
priority traffic may be the "moderate" percentage of each link
capacity, while the bandwidth constraint to be enforced for the rest
of the traffic may be the full link capacity. This would result in
high priority traffic/voice being rerouted first on the {Chicago to
Cleveland}, {Cleveland to Philadelphia} and {Philadelphia to New
York} links up to the "moderate" percentage of each of these links
and other classes of service to be routed on these links to fill up
the remaining capacity. Additional high priority traffic/voice which
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Requirements for Diff-Serv Traffic Engineering June 2001
cannot be rerouted over the {Chicago to Cleveland}, {Cleveland to
Philadelphia} and {Philadelphia to New York} links because it would
exceed their "moderate" percentage, will be rerouted along other
paths which excludes these links.
1.3. Scenario 3: Maintain relative proportion of traffic classes
Suppose an IP/MPLS network supports 3 classes of traffic. The
network administrator wants to perform Traffic Engineering to
distribute the traffic load. Assume also that proportion across
traffic classes varies significantly depending on the
source/destination POPs.
Then, with existing Traffic Engineering mechanisms, the proportion
of traffic from each class on a given link will vary depending on
multiple factors including:
- in which order the different TE-LSPs are routed
- the preemption priority associated with the different TE-LSPs
- failure situations leading to reroute
This may make it difficult or impossible for the network
administrator to configure the Diff-Serv PHBs (e.g. queue bandwidth)
to ensure that each traffic class gets the appropriate treatment.
This leads again to the requirement for DS-TE to be able to enforce
a different bandwidth constraint for different classes of traffic.
This could be used to ensure that, regardless of the order in which
tunnels are routed, regardless of their preemption priority and
regardless of the failure situation, the amount of traffic of each
class routed over a link matches the Diff-Serv scheduler
configuration on that link for the corresponding class (e.g. queue
bandwidth).
As an illustration of how DS-TE would address this scenario, the
network administrator may configure the service rate of Diff-Serv
queues to (45%,35%,20%) for classes (1,2,3) respectively. The
administrator would then build separate TE LSPs for each class and
associate to each LSP the bandwidth need for its class. The network
administrator may also want to give highest preemption priority to
the highest priority class and medium preemption priority to the
medium class. Then DS-TE could ensure that after a failure, class 1
traffic would be rerouted with first access at link capacity but
without exceeding its service rate of 45% of the link bandwidth.
Class 2 traffic would be rerouted with second access at the link
capacity but without exceeding its allotment. Note that where class
3 is the Best-Effort service, the requirement on DS-TE is to ensure
that the total amount of traffic routed across all classes does not
exceed the total link capacity of 100 (as opposed to separately
limiting the amount of Best Effort traffic to 20 even if there was
little class 1 and class 2 traffic).
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Requirements for Diff-Serv Traffic Engineering June 2001
In this scenario, DS-TE allowed to maintain a somewhat steady
distribution of different classes, even during rerouting. This
relied on the required capability of DS-TE to adjust the amount of
traffic of each class routed on a link based on the configuration of
the scheduler for that class.
Alternatively (or perhaps in addition), some network administrators
may want to solve the issue in the opposite way through the
scheduler configuration being dynamically tied into the amount of
bandwidth of the LSPs admitted for each class. This is an additional
requirement on DS-TE.
1.4. Scenario 4: Guaranteed Bandwidth Services
In addition to the Best effort service, an IP/MPLS network operator
may desire to offer a point-to-point "guaranteed bandwidth" service
whereby the provider pledges to provide a given level of performance
(bandwidth/delay/loss...) end-to-end through its network from an
ingress port to and egress port. The goal is to ensure all
"guaranteed" traffic within a subscribed traffic contract, will be
delivered within stated tolerances.
One approach for deploying such "guaranteed" service involves:
- dedicating a Diff-Serv PHB (or a Diff-Serv PSC as defined in
[DIFF-NEW]) to the "guaranteed" traffic
- policing guaranteed traffic on ingress against the traffic
contract and marking the "guaranteed" packets with the
corresponding DSCP/EXP value
Where very high level of performance is targeted for the
"guaranteed" service, it may be necessary to ensure that the amount
of "guaranteed" traffic remains below a given percentage of link
capacity on every link. Where the proportion of "guaranteed" traffic
is high, constraint based routing can be used to enforce such a
constraint.
However, the network operator may also want to simultaneously
perform Traffic Engineering of the rest of the traffic (i.e. non-
guaranteed traffic) which would require that constraint based
routing is also capable of enforcing another bandwidth constraint,
which would be less stringent than the one for guaranteed traffic.
Again, this combination of requirements can not be addressed with
existing TE mechanisms. DS-TE mechanisms allowing enforcement of a
different bandwidth constraint for guaranteed traffic and for non-
guaranteed traffic are required.
2. Detailed Requirements for DS-TE
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Requirements for Diff-Serv Traffic Engineering June 2001
2.1. DS-TE Compatibility
While DS-TE is required in a number of situations such as the ones
described above, it is important to keep in mind that using DS-TE
may impact scalability (as discussed later in this document) and
operational practices. DS-TE should only be used when existing TE
mechanisms combined with Diff-Serv can not address the network
design requirements. Many network operators may choose to not use
DS-TE, or to only use it in a limited scope within their network.
Thus, the DS-TE solution must be developed in such a way that:
(i) it raises no interoperability issues with existing deployed
TE mechanisms. Networks which do not require DS-TE must not
be impacted in any way.
(ii) it allows DS-TE deployment to the required level of
granularity and scope (e.g. only in a subset of the
topology, e.g. only for the number of Classes required in
the considered network)
2.2. Separate Bandwidth Constraints
[TEWG-FW] introduces the concept of Class-Types. The fundamental
requirement for DS-TE is to be able to enforce different bandwidth
constraints for different Class Types rather than a single one.
Based on the scenarios of section 1, DS-TE must allow the network
operator to configure the bandwidth constraints such that:
- DS-TE never routes more than P1% of EF on a given link
- DS-TE never routes more than P0% of EF+BE on that link,where
P1 and P0 are configurable separately.
Just for illustration purposes a network operator may configure
P1=70 and P0=100. In this case, DS-TE could have established at a
given time, for instance, :
- 70% worth of EF and 30% worth of BE, OR
- 50% worth of EF and 50% worth of BE, OR
- 0% worth of EF and 100% worth of BE.
Clearly, DS-TE would never establish more than 70% of EF TE-LSPs
even if there was very little or no BE TE-LSPs routed on the link.
Where 3 Class-Types are supported (e.g. CT2=EF, CT1=AF1+AF2, CT0=BE)
in the scenarios of section 1, DS-TE must allow the network operator
to configure the bandwidth constraints such that:
- DS-TE never routes more than say P2% of CT2 on a given link
- DS-TE never routes more than say P1% of CT2+CT1 on that link.
- DS-TE never routes more than say P0% of CT2+CT1+CT0 on that
link.
Just as an example, the network operator may configure P2=60, P1=80
and P0=100. In that case, DS-TE could have established at a given
time, for instance, :
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Requirements for Diff-Serv Traffic Engineering June 2001
- 60% worth of EF, 20% worth of AF and 20% worth of BE, OR
- 0% worth of EF, 80% worth of AF and 20% worth of BE, OR
- 40% worth of EF, 40% worth of AF and 20% worth of BE, OR
- 30% worth of EF, 30% worth of AF and 40% worth of BE.
Clearly, DS-TE would never establish more than 60% of EF TE-LSPs
even if there was very little or no AF and BE TE-LSPs routed on the
link. Similarly, DS-TE would never establish more than 80% worth of
EF+AF TE-LSPs even if there was very little or no BE TE-LSPs routed
on the link.
More generally, the bandwidth constraints enforced by DS-TE must
allow the following:
- if a high priority class does not use up all of its bandwidth, the
next highest priority should be able to make use of this unused
bandwidth. For instance, in the above example with 3 Class-Types,
if CT2/EF is only using 30% (instead of its maximum 60%), then
CT1/AF should be able to use up to 50%. However, if CT2/EF is
using its 60%, it is obviously necessary to limit CT1/AF to much
below 50% (i.e. to 20% in our example) in order to maintain CT2's
performance levels.
- If a lower priority class (e.g. AF) used some of the unused
bandwidth of a higher priority class (e.g. EF), the high priority
class should be able to reclaim this bandwidth where necessary
(i.e. preempt lower priority class - see section 2.5)
- lower priority class-Types (e.g Best Effort) should not be
completely starved by higher priority classes.
- Highest priority classes, should only be routed away from their
shortest path when they would exceed their own bandwidth
constraints. They should not be routed away from their shortest
path because of lower priority classes.
Therefore, where N Class-Types are supported, DS-TE must allow the
network operator to configure the following bandwidth constraints:
- never route more than P(N-1)% of CT(N-1) on a given link
- never route more than P(N-2)% of CT(N-1)+CT(N-2) on that
link.
- never route more than P(N-3)% of CT(N-1)+CT(N-2)+CT(N-3) on
that link.
- etc.
- never route more than P(0)% of CT(N-1)+CT(N-2)+... + CT(0) on
that link,
where P(N-1), P(N-2), ..., P(0) are each configurable separately for
every link.
DS-TE may optionally support additional bandwidth constraints.
2.3. Number of Class-Types
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Requirements for Diff-Serv Traffic Engineering June 2001
DS-TE must support a minimum of 4 Class-Types.
In a given network, DS-TE must not force the network administrator
to support the maximum number of Class-Types. The network
administrator must be able to deploy DS-TE for only 2, for only 3 or
for 4 Class-Types.
DS-TE must minimize the scalability impact when low number of Class-
Types are actually deployed.
DS-TE should be extensible to support more Class-Types if required.
2.4. Number of Classes
DS-TE should not constrain the number of classes that can be grouped
in a Class-Type.
2.5. Preemption
2.5.1. Preemption Within a Class-Type
DS-TE must support multiple preemption priorities within a given
Class-Type (i.e. between two TE LSPs from the same Class-Type).
Preemption within a Class-Type must operate in a similar way to how
preemption operates in existing TE:
expanding on the description of preemption in [TEWG-FW], a traffic
trunk of Class-Type CTx, say "A", can preempt another traffic trunk
of same Class-Type CTx, say "B", only if *all* of the following five
conditions hold:
(i) "A" has a relatively higher priority than "B",
(ii) "A" contends for a resource utilized by "B" (including link
bandwidth which must satisfy all the bandwidth constraints
relevant to CTx),
(iii) the resource cannot concurrently accommodate "A" and "B"
based on certain decision criteria,
(iv) "A" is preemptor enabled, and
(v) "B" is preemptable.
DS-TE must also allow the network operator to configure the TE-LSPs
of a given Class-Type so that they are all at the same preemption
priority and thus do not preempt each other.
2.5.2. Preemption Across Class-Types
DS-TE must support multiple preemption priorities across Class-Types
(i.e. between two TE LSPs from different Class-Types). Preemption
across Class-Types must operate in the following way:
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Requirements for Diff-Serv Traffic Engineering June 2001
a traffic trunk of Class-Type CTx, say "A", can preempt another
traffic trunk of another Class-Type CTy, say "B", only if *all* of
the following five conditions hold:
(i) "A" has a relatively higher priority than "B",
(ii) "A" contends for a resource utilized by "B" (including link
bandwidth which must satisfy all the bandwidth constraints
relevant to CTx). In other words, where preemption is used
across Class-Types, the high priority traffic in one Class-
Type must have the ability to pre-empt lower priority
traffic, but only while still within the constraint of the
maximum bandwidth available to that Class-Type.,
(iii) the resource cannot concurrently accommodate "A" and "B"
based on certain decision criteria,
(iv) "A" is preemptor enabled, and
(v) "B" is preemptable.
As an example, let's consider the case described in section 2.2
where the following bandwidth constraints are configured:
- DS-TE never routes more than say 70% of EF on a given link
- DS-TE never routes more than 100% of EF+BE on that link.
Let's assume that DS-TE has actually established at a given time:
- 50% worth of EF TE-LSPs and
- 50% worth of BE TE-LSPs.
Let's also assume that a new EF TE-LSP worth 10% now needs to be
established and contends for this link.
Then, DS-TE must allow preemption across Class-Types so that, if so
desired by the network administrator, it is possible to preempt 10%
worth of already established BE TE-LSPs in order to establish the
new EF TE-LSP. Note that in this case, preemption is applicable
because the new EF TE-LSP contends for link bandwidth which satisfy
all the bandwidth constraints relevant to EF (new EF TE-LSPs of
50+10% would be below 70%, and new EF+BE TE-LSPs of 50+10+50-10%
would be within 100%).
Let's assume that the above preemption took place and DS-TE now has
actually established:
- 60% worth of EF TE-LSPs and
- 40% worth of BE TE-LSPs.
Let's also assume that another new TE-LSP worth 15% now needs to be
established. Then, preemption of BE TE-LSPs is not applicable
because the new EF TE-LSP would contend for link bandwidth which
would not satisfy the bandwidth constraints relevant to EF (new EF
TE-LSPs of 60+15% would exceed the 70%).
DS-TE must also allow the network operator to configure the TE-LSPs
so that preemption across Class-Types is precluded.
2.6. Resource Class Affinity
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Requirements for Diff-Serv Traffic Engineering June 2001
[TE-REQ] defines Resource class attributes associated with links and
defines resources affinity attributes associated with a traffic
trunk which can be used to specify the class of links which are to
be explicitly included or excluded from the path of the traffic
trunk. Because these attributes already have an open semantic and
can be used to implement whatever policy is required by the Service
Provider, no new attributes, nor extensions on existing attributes
are required. The only requirement on DS-TE is to allow separate
configuration of Resource Class Affinity attributes on the traffic
trunks corresponding to each different Class of Service.
2.7. Traffic Mapping
This section describes the requirement for an LSR which is the Head-
end of Diff-Serv-aware Traffic Engineering LSPs to map incoming
traffic onto these LSPs.
DS-TE must allow each Diff-Serv-aware Traffic Engineering LSP to be
configured with the following attributes:
- the set of Diff-Serv class(es) (more precisely "Ordered
Aggregate") that it can transport in accordance with [DIFF-MPLS]
- the Class-Type that must be taken into account so that
Constraint Based Routing enforces the relevant bandwidth
constraints.
DS-TE must support mapping of incoming traffic onto Diff-Serv-aware
Traffic Engineering LSPs in accordance with [DIFF-MPLS] so that only
packets that belong to the (set of) Behavior Aggregate(s)
transported over a given Diff-Serv-aware TE LSP should be mapped to
that LSP. In particular, where the Head-end LSR is also the MPLS
Edge LSR, determination of the Behavior Aggregate (and thus
determination of the egress Diff-Serv-aware TE LSP) is based on the
Diffserv Codepoint (DSCP) in the packet header.
2.8. Dynamic Adjustment of Diff-Serv PHBs
As discussed in section 1.4, DS-TE may support adjustment of Diff-
Serv PHBs parameters (e.g. queue bandwidth) based on the amount of
TE-LSPs established for each Class/Class-Type.
Where this behavior is supported, it must allow for disabling via
configuration (thus reverting to PHB treatment with static scheduler
configuration independent of DS-TE operations).
The dynamic adjustment must take account of the performance
requirements of each class when computing required adjustments.
2.9. Multiple TE Metrics
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Requirements for Diff-Serv Traffic Engineering June 2001
This document does not specifically discuss the need for multiple TE
metrics which is already work in progress. However, we note that DS-
TE can make immediate use of multiple TE metrics once those are
available simply by allowing TE-LSPs for different Classes of
Service to be routed based on a different TE Metric.
3. Solution Evaluation Criteria
Multiple solutions can be thought of in order to support the Diff-
Serv-aware TE Requirements discussed above. For example, some
solutions may require that all current TE protocols syntax (IGP,
RSVP-TE, CR-LDP) be extended in various ways to support multiple
bandwidth constraints rather than the existing single aggregate
bandwidth constraint. Alternatively, other solutions may keep the
existing TE protocols syntax unchanged but modify their semantic to
allow for the multiple bandwidth constraints.
This section identifies the evaluation criteria that should be used
to assess potential DS-TE solutions for selection.
3.1. Satisfying detailed requirements
The solution must address all the scenarios described in section 1
and satisfy all the requirements listed in section 2.
3.2. Flexibility
- number of Class Types that can be supported, compared to
number identified in Requirements section
- number of Classes within a Class-Type
3.3. Extendibility
- how far can the solution be extended in the future if
requirements for more Class-Types are identified in the
future.
3.4. Scalability
- impact on network scalability in what is propagated,
processed, stored and computed (IGP signaling, IGP
processing, IGP database, TE-Tunnel signaling ,...).
- how does scalability impact evolve with number of Class-
Types/Classes actually deployed in a network. In
particular, is it possible to keep overhead small for a
large networks which only use a small number of Class-
Types/Classes, while allowing higher number of Class-
Types/Classes in smaller networks which can bear higher
overhead)
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Requirements for Diff-Serv Traffic Engineering June 2001
3.5. Backward compatibility/Migration
- backward compatibility/migration with/from existing TE
mechanisms
- backward compatibility/migration when
increasing/decreasing the number of Class-Types actually
deployed in a given network.
4. Security Considerations
The solution developed to address the requirements defined in this
document must address security aspects. DS-TE is not expected to add
specific security requirements beyond those of Diff-Serv and
existing TE. Networks which employ diff-serv techniques might offer
some protection between classes for denial of service attacks.
Though depending on how the technology is employed, it is possible
for some (lower scheduled) traffic to be more susceptible to traffic
anomalies (which include denial of service attacks) occurring within
other (higher scheduled) classes.
References
[TE-REQ] Awduche et al, Requirements for Traffic Engineering over
MPLS, RFC2702, September 1999.
[TEWG-FW] Awduche et al, A Framework for Internet Traffic
Engineering, draft-ietf-tewg-framework-04.txt, April 2001.
[OSPF-TE] Katz, Yeung, Traffic Engineering Extensions to OSPF,
draft-katz-yeung-ospf-traffic-04.txt, August 2001.
[ISIS-TE] Smit, Li, IS-IS extensions for Traffic Engineering, draft-
ietf-isis-traffic-02.txt, September 2000.
[RSVP-TE] Awduche et al, "RSVP-TE: Extensions to RSVP for LSP
Tunnels", draft-ietf-mpls-rsvp-lsp-tunnel-08.txt, February 2001.
[DIFF-MPLS] Le Faucheur et al, "MPLS Support of Diff-Serv", draft-
ietf-mpls-diff-ext-09.txt, April 2001
[CR-LDP] Jamoussi et al., "Constraint-Based LSP Setup using LDP",
draft-ietf-mpls-cr-ldp-05.txt, February 2001
[DIFF-NEW] Grossman, "New Terminology for Diffserv", work in
progress, draft-ietf-diffserv-new-terms-04.txt, March 2001.
Le Faucheur et. al 13
Requirements for Diff-Serv Traffic Engineering June 2001
Authors' Address:
Francois Le Faucheur
Cisco Systems, Inc.
Village d'Entreprise Green Side - Batiment T3
400, Avenue de Roumanille
06410 Biot-Sophia Antipolis
France
Phone: +33 4 97 23 26 19
Email: flefauch@cisco.com
Martin Tatham
BT
Adastral Park,
Martlesham Heath,
Ipswich IP5 3RE
UK
Phone: +44-1473-606349
Email: martin.tatham@bt.com
Thomas Telkamp
Global Crossing
Olympia 6
1213 NP Hilversum
The Netherlands
Phone: +31 35 655 651
E-mail: telkamp@gblx.net
David Cooper
Global Crossing
960 Hamlin Court
Sunnyvale, CA 94089
USA
Phone: +1 916 415 0437
E-mail: dcooper@gblx.net
Jim Boyle
Level 3 Communications, LLC.
1025 Eldorado Blvd.
Broomfield, CO, 80021
USA
Email: jboyle@Level3.net
Luca Martini
Level 3 Communications, LLC.
1025 Eldorado Blvd.
Broomfield, CO, 80021
USA
Email: luca@level3.net
Le Faucheur et. al 14
Requirements for Diff-Serv Traffic Engineering June 2001
Luyuan Fang
AT&T Labs
200 Laurel Avenue
Middletown, New Jersey 07748
USA
Phone: +1 732 420-1921
Email: luyuanfang@att.com
Gerald R. Ash
AT&T Labs
200 Laurel Avenue
Middletown, New Jersey 07748
USA
Phone: +1 732 420-4578
Email: gash@att.com
Wai Sum Lai
AT&T Labs
200 Laurel Avenue
Middletown, New Jersey 07748
USA
Phone: +1 732 420-3712
Email: wlai@att.com
Pete Hicks
CoreExpress, Inc
12655 Olive Blvd, Suite 500
St. Louis, MO 63141
USA
Phone: (314) 317-7504
Email: pete.hicks@coreexpress.net
Angela Chiu
Celion Networks
1 Sheila Drive, Suite 2
Tinton Falls, NJ 07724
Phone: +1-732 747 9987
Email: angela.chiu@celion.com
William Townsend
Tenor Networks
100 Nagog Park
Acton, MA 01720
Phone: +1-978-264-4900
Email: btownsend@tenornetworks.com
Thomas D. Nadeau
Cisco Systems, Inc.
250 Apollo Drive
Chelmsford, MA 01824
Phone: +1-978-244-3051
Email: tnadeau@cisco.com
Le Faucheur et. al 15
Requirements for Diff-Serv Traffic Engineering June 2001
Darek Skalecki
Nortel Networks
3500 Carling Ave,
Nepean K2H 8E9
Phone: +1-613-765-2252
Email: dareks@nortelnetworks.com
Le Faucheur et. al 16
Datatracker
draft-ietf-tewg-diff-te-reqts-01
Internet-Draft
