Technical Summary
This document specifies the taxonomy for MPLS-TP survivability,
the surviability architecture and key components need to meet
survivability requiremetns. Network survivability is the network's
ability to recover traffic delivery following the failure or
degradation of traffic caused by a network fault or a denial
of service attacks. Survivability isa critical characteristic of
reliable services in transport networks.
The MPLS transport profiles are designed to be consistent with
existing transport network operations and management models.
Some of the MPLS transport profile recovery mechanisms do not
depend on a control plane but use OAM mechanisms or management
actions to trigger recovery actions.
MPLS and GMPLS protection mechanisms are applicable in for the
MPLS transport profiles. It is also be possible to provision and
manage the related protection entities and functions defined in MPLS
and GMPLS using the management plane. Regardless of whether
an OAM, management, or control plane initiation mechanism is used,
the protection-switching operation is a data-plane operation.
Working Group Summary
Since the document is an output from the MPLS-TP project it is the
joint output of several IETF working groups and Qustion 9, 10, 12 and
14 of ITU-T SG15.
Document Quality
The document is well reviewed in all the groups mentioned above.
Personnel
Loa Andersson is Document Shepherd for this document.
Stewart Bryant is the Responsible Area Director.
RFC Editor Note
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1) Section 1.2: r/in[RFC4427]/in [RFC4427]
2) Section 2: I a verb is missing:
The terms "defect" and "failure" are used interchangeably to
indicate any defect or failure in the sense that they defined in
^ are
[G.806].
3) Section 4.1: r/OAM mechanisms ,/OAM mechanisms,
4) Section 4.1.3: Add period: [MPLS-TP-OAM-Framework].
^
5) Section 4.4.2: Add period: (1:n or m:n).
^
6) Section 4.4.3: Add period: service degradation.
^
7) Section 4.7: Missing ): (see Section
4.5 associated with the protection function.
8) Section 4.7.6: Extra "1"?:
Additionally, note that the shared-protection resources could be used
1 to carry extra traffic, for example, in Figure 4, an LSP JPQRK
^ ?
9) Section 6.1.1: Missing period: etc.).
^
10) Section 6.1.2: Missing periods (X2): recovery entity.
^
11) Section 6.4: r/(Maintenance Group Intermediate Points (MIPs)/MIPs
(Maintenance Group Intermediate Points)
12) Section 6.5: r/t1he/the
===========
Add a new last para to section 4.3.2
In an MPLS-TP network, the degree to which a resource is shared
between LSPs is a policy issue. This policy may be applied to the
resource or to the LSPs, and may be pre-configured, configured
per LSP and installed during LSP establishment, or may be
dynamically configured.
==========================
In Section 4.7.4
Old
An in-band, data-plane protocol for use in MPLS-TP networks will
be documented in [MPLS-TP-Linear-Protection] for this purpose.
New
An in-band, data-plane protocol for use in MPLS-TP networks will
be documented in [MPLS-TP-Linear-Protection] for linear protection
(ring protection is discussed in Section 4.8 of this document).
==========================
In Section 1.4. Scope of this Framework
Please change all instances of the word "level" to "grade"
In Section 4 Functional Architecture (main section)
Please change the word "level" to "grade"
In Section 4.1.1. Operator Control
Please change the word "level" to "grade"
In Section 4.3 Level of Recovery (main section)
Please change the word "level" to "grade"
In Section 4.3.2 Shared protection
Please change the word "level" to "grade"
In Section 4.4.1 Link-Level Protection
OLD
Link-level protection offers the following levels of protection:
NEW
Link-level protection offers the following grades of protection:
END
In Section 4.4.2. Alternate Paths and Segments
OLD
Different levels of protection may be provided:
NEW
Different grades of protection may be provided:
END
In Section 4.4.3. Protection Tunnels
OLD
Different levels of protection may be provided:
NEW
Different grades of protection may be provided:
END
In Section 4.6. Protection in Different Topologies
OLD
concatenation of recovery domains, each providing some level of
recovery in part of the network.
NEW
concatenation of recovery domains, each providing some grade of
recovery in part of the network.
END
In Section 4.9. Recovery in Layered Networks
Please change all instances of the word "level" to "grade".
However please DO NOT change "Layered" in the title of this section.
In Section 7. Pseudowire Recovery Considerations
OLD
The pseudowire may, itself, require a level of protection, in order
to meet the service-level guarantees of its SLA.
NEW
The pseudowire may, itself, require protection, in order
to meet the service-level guarantees of its SLA.
END
===============================
Change title of section
OLD
4.2. Elements of Recovery
NEW
4.2. Recovery Scope
END
===============================
In Section 4.2.1. Span Recovery
OLD
Moving the protected LSP to another TE link between the same pair of
neighbors is a form of segment recovery and is described in Section
4.2.2.
NEW
Moving the protected LSP to another TE link between the same pair of
neighbors is a form of segment recovery and not a form of span
recovery.
Segment Recovery is described in Section 4.2.2.
END
==============================
In Section 4.3. Levels of Recovery
New last paragraph
The selection of the recovery grade and schemes to satisfy the
service grades for an LSP using available network resources is
subject to network and local policy and may be pre-designated
through network planning or may be dynamically determined
by the network.
============================
In Section 4.4.3. Protection Tunnels
OLD
A protection tunnel is a hierarchical LSP that is pre-provisioned in
order to protect against a failure condition along a sequence of
spans in the network.
NEW
A protection tunnel is pre-provisioned in
order to protect against a failure condition along a sequence of
spans in the network. This may be achieved using LSP heirarchy.
END
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