wdiff draft-ietf-ccamp-te-metric-recording-02.txt draft-ietf-ccamp-te-metric-recording-03.txt

CCAMP Working Group Zafar Ali
Internet Draft George Swallow
Intended status: Standard Track Clarence Filsfils
Expires: January August 13, 2014 Matt Hartley
Cisco Systems

Kenji Kumaki
KDDI Corporation

Ruediger Kunze
Deutsche Telekom AG
July

February 14, 2013 2014

Resource ReserVation Protocol-Traffic Engineering (RSVP-TE)
extension for recording TE Metric of a Label Switched Path
draft-ietf-ccamp-te-metric-recording-02.txt
draft-ietf-ccamp-te-metric-recording-03.txt

Status of this Memo

This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.

Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet-
Drafts is at http://datatracker.ietf.org/drafts/current/.

Internet-Drafts are draft documents valid for a maximum of six
months and may be updated, replaced, or obsoleted by other
documents at any time. It is inappropriate to use Internet-Drafts
as reference material or to cite them other than as "work in
progress."

This Internet-Draft will expire on January August 13, 2014.

This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents
(http://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents
carefully, as they describe your rights and restrictions with
respect to this document. Code Components extracted from this
document must include Simplified BSD License text as described in
Section 4.e of the Trust Legal Provisions and are provided without
warranty as described in the Simplified BSD License.

This document may contain material from IETF Documents or IETF
Contributions published or made publicly available before November
10, 2008. The person(s) controlling the copyright in some of this
material may not have granted the IETF Trust the right to allow
modifications of such material outside the IETF Standards Process.
Without obtaining an adequate license from the person(s)
controlling the copyright in such materials, this document may not
be modified outside the IETF Standards Process, and derivative
works of it may not be created outside the IETF Standards Process,
except to format it for publication as an RFC or to translate it
into languages other than English.

Internet-Draft draft-ietf-ccamp-te-metric-recording-02.txt draft-ietf-ccamp-te-metric-recording-03.txt

Abstract

There are many scenarios in which Traffic Engineering (TE) metrics
such as cost, latency and latency variation associated with a
Forwarding Adjacency (FA) or Routing Adjacency (RA) Label Switched
Path (LSP) are not available to the ingress and egress nodes. This
draft provides extensions for the Resource ReserVation Protocol-
Traffic Engineering (RSVP-TE) for the support of the discovery of
cost, latency and latency variation of an LSP.

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].

Table of Contents

1. Introduction...................................................3 Introduction................................................3
2. RSVP-TE Requirement............................................3 Requirement.........................................4
2.1. Cost, Latency and Latency Variation Collection Indication....4 Indication.4
2.2. Cost, Latency and Latency Variation Collection...............4 Collection............4
2.3. Cost, Latency and Latency Variation Update...................4 Update................4
3. RSVP-TE signaling extensions...................................4 extensions................................5
3.1. Cost, Latency Latency, and Latency Variation Collection Flags.........4
3.2. Flags.....5
3.4. Cost Subobject...............................................5
3.3. subobject............................................5
3.5. Latency Subobject............................................6
3.4. subobject.........................................6
3.6. Latency Variation Subobject..................................7
3.5. subobject...............................7
3.7. Signaling Procedures.........................................8 Procedures......................................8
4. Security Considerations........................................9 Considerations....................................12
5. IANA Considerations............................................9 Considerations........................................12
5.1. RSVP Attribute Bit Flags.....................................9 Flags.................................12
Internet-Draft draft-ietf-ccamp-te-metric-recording-02.txt draft-ietf-ccamp-te-metric-recording-03.txt

5.2. New RSVP error sub-code.....................................10 sub-code..................................13
6. Acknowledgments...............................................11 Acknowledgments............................................14
7. References....................................................11 References.................................................14
7.1. Normative References........................................11 References.....................................14
7.2. Informative References......................................12 References...................................14

1. Introduction

In certain networks, such as financial information networks,
network performance information (e.g. latency, latency
variation) is becoming as critical to data path selection as
other metrics [DRAFT-OSPF-TE-METRIC], [DRAFT-ISIS-TE-METRIC]. If
cost, latency or latency variation associated with a Forwarding
Adjacency (FA) or a Routing Adjacency (RA) LSP is not available
to the ingress or egress node, it cannot be advertised as an
attribute of the FA or RA. There are many scenarios in packet and
optical networks where the route information of an LSP may not
be provided to the ingress node for confidentiality reasons
and/or the ingress node may not run the same routing instance as
the intermediate nodes traversed by the path. In such scenarios,
the ingress node cannot determine the cost, latency and latency
variation properties of the LSP's route. Similarly, in Generalized Multi-
Protocol Label Switching (GMPLS) networks signaling
bidirectional LSP, the egress node cannot determine the

One possible way to address this issue is to configure cost,
latency and latency variation properties of values manually. However, in the LSP route. A
multi-domain or multi-layer network is an example
event of such
networks. Similarly, a GMPLS User-Network Interface (UNI)
[RFC4208] is also an example of such networks.

In certain networks, LSP being rerouted (e.g. due to re-optimization),
such as financial information networks,
network performance configuration information (e.g. latency, latency
variation) may become invalid. Consequently,
in cases where that an LSP is becoming as critical to data path selection as
other metrics [DRAFT-OSPF-TE-METRIC], [DRAFT-ISIS-TE-METRIC]. If
cost, latency or latency variation associated with an FA or an
RA LSP is not available to the ingress or egress node, it cannot
be advertised as an attribute of the FA or RA. One possible way
to address this issue is to configure cost, latency and latency
variation values manually. However, in the event of an LSP being
rerouted (e.g. due to re-optimization), such configuration
information may become invalid. Consequently, in case where that
an LSP is advertised advertised as a TE-Link, the
ingress and/or egress nodes cannot provide the correct latency,
latency variation and cost attribute associated with the TE-Link
automatically.

In summary, there is a requirement for the ingress and egress
nodes to learn the cost, latency and latency variation
attributes of an FA or RA LSP. This draft provides extensions to
the Resource ReserVation Protocol-Traffic Engineering (RSVP-TE)
for the support of the automatic discovery of these attributes.

1.1. Use Cases

1.1.1. GMPLS

In Generalized Multi-Protocol Label Switching (GMPLS) networks
signaling bidirectional LSPs, the egress node cannot determine
the cost, latency and latency variation properties of the LSP
path. A multi-domain or multi-layer network is an example of
such networks. A GMPLS User-Network Interface (UNI) [RFC4208] is
also an example of such networks.

Internet-Draft draft-ietf-ccamp-te-metric-recording-03.txt

1.1.2. Inter-area tunnels with loose-hops

When a LSP is established over multiple IGP-areas using loose
hops in the ERO, the ingress node only has knowledge of the
first IGP-area traversed by the LSP. In this case, it cannot
determine the cost, latency and latency variation properties of
the LSP path.

2. RSVP-TE Requirement Requirements

This section outlines RSVP-TE requirements for the support of
the automatic discovery of cost, latency and latency variation
attributes of an LSP. These requirements are very similar to the
requirement of discovering the Shared Risk Link Groups (SRLGs)
associated with the route taken by an LSP [DRAFT-SRLG-
RECORDING].

Internet-Draft draft-ietf-ccamp-te-metric-recording-02.txt

2.1. Cost, Latency and Latency Variation Collection Indication

The ingress node of the LSP must be capable of indicating
whether the cost, latency and latency variation attributes of
the LSP should be collected during the signaling procedure of
setting up the LSP. No cost, latency or latency variation
information is collected without an explicit request being made
by the ingress node.

2.2. Cost, Latency and Latency Variation Collection

If requested, cost, latency and latency variation is
collected during the setup of an LSP. The endpoints of the LSP
may use the collected information for routing, flooding and TE
link configuration and other purposes.

2.3. Cost, Latency and Latency Variation Update

When the cost, latency and or latency variation property of a TE
link along the route of a LSP for which that property was
collected changes, e.g., changes (e.g., if the administrator changes the cost
of a TE link, link traversed by the LSP), the node where the change
occurred needs to be capable of updating the cost, latency and
latency variation information of the path and signaling this to
the end-points. Similarly, if a path segment of the LSP is
rerouted, the endpoints of the re-
routed re-routed segment need to be
capable of updating the cost, latency and latency variation
information of the path. Any node, node which adds cost, latency or
latency variation information to an LSP during initial setup,
needs to signal changes to these values to both endpoints.

2.4. Cost Definition

Although the terms latency and latency variation are well
understood, "cost" may be ambiguous; in particular, in the
Internet-Draft draft-ietf-ccamp-te-metric-recording-03.txt

context of a LSP that traverses nodes and links operated by
different entities, there may be no common definition of cost.
However, there are situations in which the entire LSP may be
within a single AS (e.g. inter-area LSPs) in which cost
discovery is useful.

The precise meaning and interpretation of numerical costs is a
matter for the network operator. For the purposes of this
document, two constraints are assumed:

. A higher cost represents an inferior path

. Simple addition of costs for different sections of a path
must make sense.

3. RSVP-TE signaling extensions

3.1. Cost, Latency and Latency Variation Collection Flags

Three

In order to indicate nodes that cost, latency and/ or latency
variation collection is desired, the following three Attribute
flags are defined in the Attribute Flags TLV,
which can be set and carried in either the LSP_ATTRIBUTES or
LSP_REQUIRED_ATTRIBUTES Objects.

- Cost Collection flag (to TLV:

- Cost Collection flag (to be assigned by IANA)

- Latency Collection flag (to be assigned by IANA)

- Latency Variation Collection flag (to be assigned by IANA)

These flags are meaningful in a Path message. If the Cost
Collection flag is set to 1, the transit nodes SHOULD report the
cost information in the Record Route Objects (RRO) of both the
Path and Resv messages.

Internet-Draft draft-ietf-ccamp-te-metric-recording-02.txt

If the Cost Collection flag is set to 1, the transit nodes
SHOULD report latency variation information in the Record Route
Objects (RRO) of both the Path and Resv messages.

If the Latency Collection flag is set to 1, the transit nodes
SHOULD report latency variation information carried in either the Record Route LSP_ATTRIBUTES or
LSP_REQUIRED_ATTRIBUTES Objects (RRO) of both the Path and Resv messages.

If the Latency Variation Collection flag is set to 1, the
transit nodes SHOULD report latency variation information in the
Record Route Objects (RRO) of both the a Path and Resv messages.

The procedure for the processing the Attribute Flags TLV follows
[RFC5420]. message.

3.2. Cost Subobject

The cost Cost subobject is defined for the a new RRO (ROUTE_RECORD OBJECT) sub-object
used to record the cost information of the LSP. Its format is
similar to the other RRO subobjects (ROUTE_RECORD sub-object) defined in [RFC3209].

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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length | Reserved (must be zero) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Downstream Cost |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Upstream Cost |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

Type: TBA1 - Cost subobject (to be assigned by IANA).

Internet-Draft draft-ietf-ccamp-te-metric-recording-03.txt

Length: The Length value is set to 8 or 12 depending on the
presence of Upstream Cost information. It MUST NOT be set to
any other value.

Reserved: This field is reserved for future use. It MUST be
set to 0 when sent on transmission and MUST be ignored when received.

Downstream Cost: Cost of the local link along the route of
the LSP in the direction of the tail-end node, encoded as a
32-bit integer. Based on the policy at the recording node,
the cost value can be set to the Interior Gateway Protocol
(IGP) metric or TE metric of the link in question. This approach has been taken to avoid
defining a flag for each cost type in the Attribute-Flags
TLV. It is assumed that,
based on policy, all nodes report the same cost-type and that
Internet-Draft draft-ietf-ccamp-te-metric-recording-02.txt

the ingress and egress nodes know the cost type reported in
the RRO.

Upstream Cost: Cost of the local link along the route of the
LSP in the direction of the head-end node, encoded as a 32-
bit integer. Based on the policy at the recording node, the
cost value can be set

3.3. Latency Subobject

The Latency subobject is a new RRO sub-object to record the Interior Gateway Protocol (IGP)
metric or TE metric
latency information of the link in question. This approach
has been taken to avoid defining a flag for each cost type in
the Attribute-Flags TLV. It is assumed that, based on policy,
all nodes report the same cost-type and that the ingress and
egress nodes know the cost type reported in the RRO.

3.3. Latency Subobject

The Latency subobject is defined for RRO to record the latency
information of the LSP. Its format is similar the RRO subobjects
defined LSP. Its format is similar the other
RRO subobjects defined in [RFC3209].

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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length | Reserved (must be zero) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|A| Reserved | Downstream Delay |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|A| Reserved | Upstream Delay |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

Type: TBA2 - Latency subobject (to be assigned by IANA).

Length: 8 or 12 depending on the presence of Upstream Cost Delay
information.

A-bit: These fields represent the Anomalous (A) bit
associated with the Downstream and Upstream Delay
respectively, as defined in [DRAFT-OSPF-TE-METRIC].

Reserved: These fields are reserved for future use. They MUST
be set to 0 when sent and MUST be ignored when received.

Downstream Delay: Delay of the local link along the route of
the LSP in the direction of the tail-end node, encoded as 24-
bit integer. When set to 0, it has not been measured. integer, as defined in [DRAFT-OSPF-TE-METRIC]. When set
Internet-Draft draft-ietf-ccamp-te-metric-recording-03.txt

to the maximum value 16,777,215 (16.777215 sec), the delay is
at least that value and may be larger.

Upstream Delay: Delay of the local link along the route of
the LSP in the direction of the head-end node, encoded as 24-
Internet-Draft draft-ietf-ccamp-te-metric-recording-02.txt
bit integer. When set to 0, it has not been measured. integer, as defined in [DRAFT-OSPF-TE-METRIC]. When set
to the maximum value 16,777,215 (16.777215 sec), the delay is
at least that value and may be larger.

3.4. Latency Variation Subobject

The Latency Variation subobject is defined for a new RRO sub-object to
record the Latency Variation information of the LSP. Its format
is similar to the other RRO subobjects defined in [RFC3209].

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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length | Reserved (must be zero) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|A| Reserved | Downstream Delay Variation |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|A| Reserved | Upstream Delay Variation |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

Type: TBA3 - Latency Variation subobject (to be assigned by
IANA).

Length: 8 or 12 depending on the presence of Upstream Latency
Variation information.

A-bit: These fields represent the Anomalous (A) bit
associated with the Downstream and Upstream Delay Variation
respectively, as defined in [DRAFT-OSPF-TE-METRIC].

Reserved: These fields are reserved for future use. It MUST SHOULD
be set to 0 when sent and MUST be ignored when received.

Downstream Delay Variation: Delay Variation of the local link
along the route of the LSP in the direction of the tail-end
node, encoded as 24-bit integer. When set to 0, it has not
been measured. integer, as defined in [DRAFT-OSPF-
TE-METRIC]. When set to the maximum value 16,777,215
(16.777215 sec), the delay is at least that value and may be
larger.

Upstream Delay Variation: Delay Variation of the local link
along the route of the LSP in the direction of the head-end
node, encoded as 24-bit integer. When set to 0, it has not
been measured. When set to the maximum value 16,777,215
Internet-Draft draft-ietf-ccamp-te-metric-recording-03.txt

(16.777215 sec), the delay is at least that value and may be
larger.

Internet-Draft draft-ietf-ccamp-te-metric-recording-02.txt

3.5.

4. Signaling Procedures

The rules for processing the LSP_ATTRIBUTES and
LSP_REQUIRED_ATTRIBUTES Objects and RRO defined in [RFC5420] are
not changed.

4.1. Collection request

Typically, the ingress node learns the route of an LSP by adding
a RRO in the Path message. If an ingress node also desires cost,
latency and/or latency variation recording, it sets MUST set the
appropriate flag(s) in the Attribute Flags TLV of the
LSP_ATTRIBUTES (if recording is desired but not mandatory) or
LSP_REQUIRED_ATTRIBUTES (if recording in mandatory) Object.
None, all or any of the Cost Collection, Latency Collection or
Latency Variation Collection flags may MAY be set in the Attribute
Flags TLV of the LSP_ATTRIBUTES or LSP_REQUIRED_ATTRIBUTES
Object. The rules for processing the LSP_ATTRIBUTES and
LSP_REQUIRED_ATTRIBUTES Objects These flags affect both Path and Resv RRO are not changed. processing, as
described below.

The
corresponding sub-objects Cost Collection, Latency Collection or Latency Variation
Collection flags SHOULD NOT be set in an Attribute Flags TLV in
a Resv message. If any of these flags is set in a received
Attribute Flags TLV in a Resv message, it MUST be included ignored.

The Cost Collection, Latency Collection or Latency Variation
Collection flags SHOULD NOT be set in the an Attribute Flags TLV in
a RRO. If any of these flags is set in a received Attribute
Flags TLV in a RRO, with the
Downstream (only) information filled in.

When it MUST be ignored.

4.2. Path and Resv message processing

4.2.1. Cost

If a node receives a Path message which carries an containing a
LSP_REQUIRED_ATTRIBUTES Object and with the Cost, Latency and/or
Latency Variation Cost Collection Flag(s) is (are) set, if Flag set
in the Attribute Flags TLV:

. If local policy disallows providing the requested
information to the endpoints, the node MUST return a Path
Error message with error code "Policy Control Failure (2)" Failure" (2)
and one of the following error
subcodes:

. subcode "Cost Recoding Recording Rejected" (value to be assigned
by IANA, suggested value 105) if Cost Collection Flag is set. 105).

. "Latency Recording Rejected" (value It SHOULD add a Cost subobject to be assigned by IANA,
suggested value 106) the Path and Resv RROs
for the LSP. It SHOULD supply only downstream information
for a unidirectional LSP, and SHOULD provide both upstream
Internet-Draft draft-ietf-ccamp-te-metric-recording-03.txt

and downstream information if Latency Collection Flag a bidirectional LSP is set. being
signaled.

. "Latency Variation Recording Rejected" (value to be assigned
by IANA, suggested value 107) if Latency Variation Collection
Flag If Cost information is set.

When not known, a Cost subobject SHOULD
NOT be added to either the Path or Resv RRO.

If a node receives a Path message which carries an containing a LSP_ATTRIBUTES
Object and with the Cost, Latency and/or Latency
Variation Cost Collection Flag(s) is (are) set, if Flag set in the Attribute Flags
TLV:

. If local policy disallows providing the requested
information to the endpoints, the Path message SHOULD NOT rejected due to Metric recording
restriction and the Path message
be rejected. A Cost subobject is forwarded without the
appropriate sub-object(s) in not added to the Path or
Resv RRO.

. If local policy permits the recording of the requested
information, the processing node permits, it SHOULD add the requested
subobject(s) with the cost, latency and/or latency variation
metric value(s) associated with the local hop a Cost subobject to
the Path RRO.
If and Resv RROs for the LSP being setup is bidirectional, LSP. It SHOULD supply only
downstream information for a unidirectional LSP, and SHOULD
provide both Downstream upstream and
Upstream downstream information SHOULD be included. If the if a
bidirectional LSP is
unidirectional, only Downstream being signaled.

. If Cost information is not known, a Cost subobject SHOULD
NOT be included.

Following added to either the steps described above, Path or Resv RRO.

When adding a Cost subobject to a Path or Resv RRO:

. The Downstream Cost is set to the intermediate nodes cost of the local link
used by the LSP provide in the requested direction of the egress node. It
SHOULD be set to zero by the egress node.

. The Upstream Cost, if set, is set to the cost of the local
link used by the LSP in the direction of the ingress node.
It SHOULD be set to zero by the ingress node.

. The cost of a local link is the Interior Gateway Protocol
(IGP) metric value(s) associated or TE metric of the link in question,
depending on the policy of the processing node.

4.2.2. Latency

If a node receives a Path message containing a
LSP_REQUIRED_ATTRIBUTES Object with the Latency Collection Flag
set in the Attribute Flags TLV:

. If local policy disallows providing the requested
information to the endpoints, the node MUST return a Path
Error message with error code "Policy Control Failure" (2)
and subcode "Latency Recording Rejected" (value to be
assigned by IANA, suggested value 106).

. It SHOULD add a Latency subobject to the Path and Resv
RROs for the LSP. It SHOULD supply only downstream
Internet-Draft draft-ietf-ccamp-te-metric-recording-02.txt draft-ietf-ccamp-te-metric-recording-03.txt

information for a unidirectional LSP, and SHOULD provide
both upstream and downstream information if a bidirectional
LSP is being signaled.

. If Latency information is not known, a Latency subobject
SHOULD NOT be added to either the Path or Resv RRO.

If a node receives a Path message containing a LSP_ATTRIBUTES
Object with the Latency Collection Flag set in the Attribute
Flags TLV:

. If local policy disallows providing the requested
information to the endpoints, the Path message SHOULD NOT
be rejected. A Latency subobject is not added to the Path
or Resv RRO.

. If local hop policy permits, it SHOULD add a Latency subobject
to the Path and Resv RROs for the LSP. It SHOULD supply
only downstream information for a unidirectional LSP, and
SHOULD provide both upstream and downstream information if
a bidirectional LSP is being signaled.

. If Latency information is not known, a Latency subobject
SHOULD NOT be added to either the Path or Resv RRO.

When adding a Latency subobject to a Path or Resv RRO:

. The Downstream Delay is set to the delay of the local link
used by the LSP in the direction of the egress node. It
SHOULD be set to zero by the egress node.

. The Upstream Delay, if set, is set to the delay of the
local link used by the LSP in the direction of the ingress
node. It SHOULD be set to zero by the ingress node.

. The A-bit for the downstream and upstream latency SHOULD
be set as described in [DRAFT-OSPF-TE-METRIC].

4.2.3. Latency Variation

If a node receives a Path message containing a
LSP_REQUIRED_ATTRIBUTES Object with the Latency Variation
Collection Flag set in the Attribute Flags TLV:

. If local policy disallows providing the requested
information to the endpoints, the node MUST return a Path
Error message with error code "Policy Control Failure" (2)
and subcode "Latency Variation Recording Rejected" (value
to be assigned by IANA, suggested value 107).

. It SHOULD add a Latency Variation subobject to the Path
and Resv RROs for the LSP. It SHOULD supply only downstream
Internet-Draft draft-ietf-ccamp-te-metric-recording-03.txt

information for a unidirectional LSP, and SHOULD provide
both upstream and downstream information if a bidirectional
LSP is being signaled.

. If Latency Variation information is not known, a Latency
subobject SHOULD NOT be added to either the Path or Resv
RRO.

If a node receives a Path message containing a LSP_ATTRIBUTES
Object with the Latency Variation Collection Flag set in the
Attribute Flags TLV:

. If local policy disallows providing the requested
information to the endpoints, the Path message SHOULD NOT
be rejected. A Latency Variation subobject is not added to
the Path or Resv RRO.

. If local policy permits, it SHOULD add a Latency Variation
subobject to the Path and Resv RROs for the LSP. It SHOULD
supply only downstream information for a unidirectional
LSP, and SHOULD provide both upstream and downstream
information if a bidirectional LSP is being signaled.

. If Latency Variation information is not known, a Latency
subobject SHOULD NOT be added to either the Path or Resv
RRO.

When adding a Latency Variation subobject to a Path or Resv RRO:

. The Downstream Latency Variation is set to the latency of
the local link used by the LSP in the direction of the
egress node. It SHOULD be set to zero by the egress node.

. The Upstream Latency Variation, if set, is set to the
latency of the local link used by the LSP in the direction
of the ingress node. It SHOULD be set to zero by the egress
node.

. The A-bit for the downstream and upstream latency SHOULD
be set as described in the Path RRO. [DRAFT-OSPF-TE-METRIC].

4.3. Metric Update

When the egress node receives the
Path message, it can calculate the end-to-end cost, latency and/or latency variation properties information of the LSP.

Before the Resv message a
link is sent to changed, the upstream node, corresponding metric values for the egress LSPs
using that link should also be updated. If node adds the requested subobject(s) with the downstream cost,
latency has added Cost,
Latency and/or latency variation metric value(s) associated with
the local hop Latency Variation subobjects to the Path or Resv RRO in a similar manner to that
specified above for
RRO, the addition procedures defined in Section 4.4.3 of Path RRO sub-objects by
transit nodes.

Similarly, RFC 3209
[RFC3209] MUST be used to communicate any changes to relevant
information to the intermediate other nodes of the LSP provide the
requested metric value(s) associated with on the local hop in LSP's path. The node need
not send an update for changes to information which has not been
added to the
Resv RRO. When the

Internet-Draft draft-ietf-ccamp-te-metric-recording-03.txt

5. Endpoint processing

The ingress node receives the Resv message, it can and egress nodes of a LSP may calculate the end-to-end end-to-
end cost, latency and/or latency variation properties of the LSP. LSP
from the supplied values in the Resv or Path RRO respectively.

Typically, cost and latency are additive metrics, but latency
variation is not an additive metric. The means by which the
ingress and egress nodes compute the end-to-end cost, latency
and latency variation metric from information recorded in the
RRO is a local decision and is beyond the scope of this
document.

Based on the local policy, the ingress and egress nodes can
advertise the calculated end-to-end cost, latency and/or latency
variation properties of the FA or RA LSP in TE link
advertisement to the routing instance based on the procedure
described in [DRAFT-OSPF-TE-METRIC], [DRAFT-ISIS-TE-METRIC].

Based on the local policy, a transit node (e.g. the edge node of
a domain) may edit a Path or Resv RRO to remove route
information (e.g. node or interface identifier information)
before forwarding it. A node that does this SHOULD summarize the
cost, latency and latency variation data removed as a single
value for each for the loose hop that is summarized by the
transit node. and SHOULD follow
procedure defined in [DRAFT-RRO-EDIT]. How a transit node that performs
the RRO edit operation calculates the cost, latency o and/or
latency variation metric for the segment summarized by
the transit node is beyond the scope of this document.

6. Security Considerations

This document does not introduce any additional security issues
above those identified in [RFC5920], [RFC5420], [RFC2205],
[RFC3209], and [RFC3473].

7. IANA Considerations

5.1.

7.1. RSVP Attribute Bit Flags

The IANA has created a registry and manages the space of
attributes bit flags of Attribute Flags TLV as described in
section 11.3 of [RFC5420]. It is requested that the IANA makes
Internet-Draft draft-ietf-ccamp-te-metric-recording-02.txt
assignments from the Attribute Bit Flags defined in this
document.

This document introduces the following three new Attribute
Bit Flag:

- Bit number: TBD (recommended bit position 11)

- Defining RFC: this I-D

- Name of bit: Cost Collection Flag
Internet-Draft draft-ietf-ccamp-te-metric-recording-03.txt

- Bit number: TBD (recommended bit position 12)

- Defining RFC: this I-D

- Name of bit: Latency Collection Flag

- Bit number: TBD (recommended bit position 13)

- Defining RFC: this I-D

- Name of bit: Latency Variation Flag

5.2. ROUTE_RECORD subobject

This document introduces the following three new RRO
subobject:

Type Name Reference

--------- ---------------------- ---------

TBD (35) Cost subobject This I-D

TBD (36) Latency subobject This I-D

TBD (37) Latency Variation subobject This I-D

5.2.

7.2. New RSVP error sub-code

For Error Code = 2 "Policy Control Failure" (see [RFC2205]) the
following sub-code is defined.

Sub-code Value
-------- -----
Internet-Draft draft-ietf-ccamp-te-metric-recording-02.txt

Cost Recoding Rejected To be assigned by IANA.
Suggested Value: 105.

Latency Recoding Rejected To be assigned by IANA.
Suggested Value: 106.

Latency Variation Recoding Rejected To be assigned by IANA.
Suggested Value: 107.

Internet-Draft draft-ietf-ccamp-te-metric-recording-03.txt

8. Acknowledgments

Authors would like to thank Ori Gerstel, Gabriele Maria
Galimberti, Luyuan Fang and Walid Wakim for their review
comments.

9. References

7.1.

9.1. Normative References

[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.

[RFC3209] Awduche, D., Berger, L., Gan, D., Li, T., Srinivasan,
V., and G. Swallow, "RSVP-TE: Extensions to RSVP for
LSP Tunnels", RFC 3209, December 2001.

[RFC5420] Farrel, A., Ed., Papadimitriou, D., Vasseur, JP., and
A. Ayyangarps, "Encoding of Attributes for MPLS LSP
Establishment Using Resource Reservation Protocol
Traffic Engineering (RSVP-TE)", RFC 5420, February
2009.

[DRAFT-OSPF-TE-METRIC] S. Giacalone, D. Ward, J. Drake, A.
Atlas, S. Previdi, "OSPF Traffic Engineering (TE)
Metric Extensions", draft-ietf-ospf-te-metric-
extensions, work in progress.

[DRAFT-ISIS-TE-METRIC] S. Previdi, S. Giacalone, D. Ward, J.
Drake, A. Atlas, C. Filsfils, "IS-IS Traffic
Engineering (TE) Metric Extensions", draft-ietf-isis-
te-metric-extensions, work in progress.

[DRAFT-SRLG-RECORDING] F. Zhang, D. Li, O. Gonzalez de Dios, C.
Margaria,, "RSVP-TE Extensions for Collecting SRLG
Information", draft-ietf-ccamp-rsvp-te-srlg-
collect.txt, work in progress.

Internet-Draft draft-ietf-ccamp-te-metric-recording-02.txt

7.2.

9.2. Informative References

[RFC4208] Swallow, G., Drake, J., Ishimatsu, H., and Y. Rekhter,
"Generalized Multiprotocol Label Switching (GMPLS)
User-Network Interface (UNI): Resource ReserVation
Protocol-Traffic Engineering (RSVP-TE) Support for the
Overlay Model", RFC 4208, October 2005.

[RFC2209] Braden, R. and L. Zhang, "Resource ReSerVation
Protocol (RSVP) -- Version 1 Message Processing
Rules", RFC 2209, September 1997.

[RFC5920] Fang, L., Ed., "Security Framework for MPLS and GMPLS
Networks", RFC 5920, July 2010.

Internet-Draft draft-ietf-ccamp-te-metric-recording-03.txt

[DRAFT-SRLG-RECORDING] F. Zhang, D. Li, O. Gonzalez de Dios, C.
Margaria,, "RSVP-TE Extensions for Collecting SRLG
Information", draft-ietf-ccamp-rsvp-te-srlg-
collect.txt, work in progress.

Authors' Addresses

Zafar Ali
Cisco Systems, Inc.
Email: zali@cisco.com

George Swallow
Cisco Systems, Inc.
swallow@cisco.com

Clarence Filsfils
Cisco Systems, Inc.
cfilsfil@cisco.com

Matt Hartley
Cisco Systems
Email: mhartley@cisco.com

Kenji Kumaki
KDDI Corporation
Email: ke-kumaki@kddi.com

Rudiger Kunze
Deutsche Telekom AG
Ruediger.Kunze@telekom.de