MPLS Working Group E. Bellagamba, Ed.
Internet-Draft G. Mirsky, Ed.
Intended status: Standards Track Ericsson
Expires: April 3, 2015 L. Andersson
Huawei
P. Skoldstrom, Ed.
Acreo AB
D. Ward
Cisco
J. Drake
Juniper
September 30, 2014
Configuration of Pro-Active Operations, Administration, and Maintenance
(OAM) Functions for MPLS-based Transport Networks using LSP Ping
draft-ietf-mpls-lsp-ping-mpls-tp-oam-conf-07
Abstract
This specification describes the configuration of pro-active MPLS-TP
Operations, Administration, and Maintenance (OAM) Functions for a
given LSP using a set of TLVs that are carried by the LSP-Ping
protocol.
Status of This Memo
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Copyright Notice
Copyright (c) 2014 IETF Trust and the persons identified as the
document authors. All rights reserved.
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
1.1. Conventions used in this document . . . . . . . . . . . . 4
1.1.1. Terminology . . . . . . . . . . . . . . . . . . . . . 4
1.1.2. Requirements Language . . . . . . . . . . . . . . . . 4
2. Theory of Operations . . . . . . . . . . . . . . . . . . . . 4
2.1. MPLS OAM Configuration Operation Overview . . . . . . . . 4
2.1.1. Configuration of BFD sessions . . . . . . . . . . . . 5
2.1.2. Configuration of Performance Monitoring . . . . . . . 6
2.1.3. Configuration of Fault Management Signals . . . . . . 6
2.2. MPLS OAM Functions TLV . . . . . . . . . . . . . . . . . 6
2.2.1. BFD Configuration sub-TLV . . . . . . . . . . . . . . 8
2.2.2. Local Discriminator sub-TLV . . . . . . . . . . . . . 10
2.2.3. Negotiation Timer Parameters sub-TLV . . . . . . . . 10
2.2.4. BFD Authentication sub-TLV . . . . . . . . . . . . . 12
2.2.5. Performance Measurement sub-TLV . . . . . . . . . . . 12
2.2.6. PM Loss Measurement sub-TLV . . . . . . . . . . . . . 14
2.2.7. PM Delay Measurement sub-TLV . . . . . . . . . . . . 15
2.2.8. Fault Managemet Signal sub-TLV . . . . . . . . . . . 16
2.2.9. Source MEP-ID sub-TLV . . . . . . . . . . . . . . . . 17
3. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 18
3.1. TLV and sub-TLV Allocation . . . . . . . . . . . . . . . 18
3.2. OAM configuration errors . . . . . . . . . . . . . . . . 18
4. Security Considerations . . . . . . . . . . . . . . . . . . . 19
5. References . . . . . . . . . . . . . . . . . . . . . . . . . 19
5.1. Normative References . . . . . . . . . . . . . . . . . . 19
5.2. Informative References . . . . . . . . . . . . . . . . . 20
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 21
1. Introduction
This document describes the configuration of pro-active MPLS-TP
Operations, Administration, and Maintenance (OAM) Functions for a
given LSP using TLVs carried in LSP-Ping [RFC4379]. In particular it
specifies the mechanisms necessary to establish MPLS-TP OAM entities
at the maintenance points for monitoring and performing measurements
on an LSP, as well as defining information elements and procedures to
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configure pro-active MPLS-TP OAM functions running between LERs.
Initialization and control of on-demand MPLS-TP OAM functions are
expected to be carried out by directly accessing network nodes via a
management interface; hence configuration and control of on-demand
OAM functions are out-of-scope for this document.
The Transport Profile of MPLS must, by definition [RFC5654], be
capable of operating without a control plane. Therefore there are
several options for configuring MPLS-TP OAM, without a control plane
by either using an NMS or LSP Ping, or with a control plane using
signaling protocols RSVP-TE [RFC3209] and/or T-LDP [RFC5036].
MPLS Transport Profile (MPLS-TP) describes a profile of MPLS that
enables operational models typical in transport networks, while
providing additional OAM, survivability and other maintenance
functions not currently supported by MPLS. [RFC5860] defines the
requirements for the OAM functionality of MPLS-TP.
Pro-active MPLS-TP OAM is performed by set of protocols, Bi-
directional Forwarding Detection (BFD) [RFC6428] for Continuity
Check/Connectivity Verification, the delay measurement protocol (DM)
[RFC6374], [RFC6375] for delay and delay variation (jitter)
measurements, and the loss measurement (LM) protocol [RFC6374],
[RFC6375] for packet loss and throughput measurements. Additionally
there is a number of Fault Management Signals that can be configured.
BFD is a protocol that provides low-overhead, fast detection of
failures in the path between two forwarding engines, including the
interfaces, data link(s), and, to the extent possible, the forwarding
engines themselves. BFD can be used to detect the continuity and
mis-connection defects of MPLS-TP point-to-point and might also be
extended to support point-to-multipoint label switched paths (LSPs).
The delay and loss measurements protocols [RFC6374], [RFC6375] use a
simple query/response model for performing both uni- and bi-
directional measurements that allow the originating node to measure
packet loss and delay in forward or forward and reverse directions.
By timestamping and/or writing current packet counters to the
measurement packets at four times (Tx and Rx in both directions)
current delays and packet losses can be calculated. By performing
successive delay measurements the delay and/or inter-packet delay
variation (jitter) can be calculated. Current throughput can be
calculated from the packet loss measurements by dividing the number
of packets sent/received with the time it took to perform the
measurement, given by the timestamp in LM header. Combined with a
packet generator the throughput measurement can be used to measure
the maximum capacity of a particular LSP. It should be noted that
here we are not configuring on-demand throughput estimates based on
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saturating the connection as defined in [RFC6371]. Rather, we only
enable the estimation of the current throughput based on loss
measurements.
1.1. Conventions used in this document
1.1.1. Terminology
BFD - Bidirectional Forwarding Detection
DM - Delay Measurement
FMS - Fault Management Signal
G-ACh - Generic Associated Channel
LSP - Label Switched Path
LM - Loss Measurement
MEP - Maintanence Entity Group End Point
MPLS - Multi-Protocol Label Switching
MPLS-TP - MPLS Transport Profile
PM - Performance Measurement
1.1.2. Requirements Language
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in RFC 2119 [RFC2119].
2. Theory of Operations
2.1. MPLS OAM Configuration Operation Overview
The MPLS-TP OAM tool set is described in the [RFC6669].
LSP Ping, or alternatively RSVP-TE [RSVP-TE-CONF], can be used to
simply enable the different OAM functions, by setting the
corresponding flags in the MPLS OAM Functions TLV, Section 2.2. For
a more detailed configuration one may include sub-TLVs for the
different OAM functions in order to specify various parameters in
detail.
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Typically intermediate nodes should not process or modify any of the
OAM configuration TLVs but simply forward them to the end-node.
There is one exception to this and that is if the FMS sub-TLV,
Section 2.2.8, is present. This sub-TLV has to be examined even by
intermediate nodes. The sub-TLV MAY be present if a flag is set in
the MPLS OAM Functions TLV.
2.1.1. Configuration of BFD sessions
For this specification, BFD MUST be run in either one of the two
modes:
- Asynchronous mode, where both sides should be in active mode
- Unidirectional mode
In the simplest scenario LSP Ping [RFC5884], or alternatively RSVP-TE
[RSVP-TE CONF], is used only to bootstrap a BFD session for an LSP,
without any timer negotiation.
Timer negotiation can be performed either in subsequent BFD control
messages (in this case the operation is similar to LSP Ping based
bootstrapping described in [RFC5884]) or directly in the LSP-Ping
configuration messages.
When BFD Control packets are transported in the ACH encapsulation
they are not protected by any end-to-end checksum, only lower-layers
are providing error detection/correction. A single bit error, e.g. a
flipped bit in the BFD State field could cause the receiving end to
wrongly conclude that the link is down and in turn trigger protection
switching. To prevent this from happening the BFD Configuration sub-
TLV, Section 2.2.1, has an Integrity flag that when set enables BFD
Authentication using Keyed SHA1 with an empty key (all 0s) [RFC5880].
This would make every BFD Control packet carry an SHA1 hash of itself
that can be used to detect errors.
If BFD Authentication using a pre-shared key/password is desired
(i.e. authentication and not only error detection) the BFD
Authentication sub-TLV, Section 2.2.4, MUST be included in the BFD
Configuration sub-TLV. The BFD Authentication sub-TLV is used to
specify which authentication method that should be used and which
pre-shared key/ password that should be used for this particular
session. How the key exchange is performed is out of scope of this
document.
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2.1.2. Configuration of Performance Monitoring
It is possible to configure Performance Monitoring functionalities
such as Loss, Delay, Delay/Interpacket Delay variation (jitter), and
Throughput as described in [RFC6374].
When configuring Performance monitoring functionalities it is
possible to choose either the default configuration, by only setting
the respective flags in the MPLS OAM functions TLV, or a customized
configuration. To customize the configuration one would set the
respective flags in the including the respective Loss and/or Delay
sub-TLVs).
By setting the PM Loss flag in the MPLS OAM Functions TLV and
including the PM Loss sub-TLV, Section 2.2.6, one can configure the
measurement interval and loss threshold values for triggering
protection.
Delay measurements are configured by setting PM Delay flag in the
MPLS OAM Functions TLV and including the PM Delay sub-TLV,
Section 2.2.7, one can configure the measurement interval and the
delay threshold values for triggering protection.
2.1.3. Configuration of Fault Management Signals
To configure Fault Management Signals (FMS) and their refresh time
the FMS flag in the MPLS OAM Functions TLV MUST be set and the FMS
sub-TLV MUST be included. When configuring FMS, an implementation
can enable the default configuration by setting the FMS flag in the
OAM Function Flags sub-TLV. If an implementation wishes to modify
the default configuration it includes a MPLS OAM FMS sub-TLV.
If an intermediate point is meant to originate fault management
signal messages this means that such an intermediate point is
associated to a Server MEP through a co-located MPLS-TP client/server
adaptation function. Such a Server MEP needs to be configured by its
own LSP-ping session or, alternatively, via an NMS or RSVP-TE.
However, by setting the S flag Section 2.2.8 in the FMS sub-TLV a
client LSP can indicate that it would like an association to be
created to the server MEP(s) on any intermediate nodes.
2.2. MPLS OAM Functions TLV
The MPLS OAM Functions TLV presented in Figure 1 is carried as a TLV
of the LSP Echo request/response messages [RFC4379].
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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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| MPLS OAM Func. Type (TBD1) | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|C|V|L|D|F| Must be zero |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
~ sub-TLVs ~
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 1: MPLS OAM Functions TLV format
The MPLS OAM Functions TLV contains a number of flags indicating
which OAM functions should be activated as well as OAM function
specific sub-TLVs with configuration parameters for the particular
function.
Type: indicates the MPLS OAM Functions TLV Section 3.
Length: the length of the MPLS OAM Function Flags field including the
total length of the sub-TLVs in octets.
MPLS OAM Function Flags: a bitmap numbered from left to right as
shown in the figure.
These flags are defined in this document as presented in Table 1:
+------------+--------------------+---------------------------------+
| Bit | MPLS OAM Function | Description |
| Position | Flag | |
+------------+--------------------+---------------------------------+
| 0 | C | Continuity Check (CC) |
| 1 | V | Connectivity Verification (CV) |
| 2 | F | Fault Management Signal (FMS) |
| 3 | L | Performance Measurement/Loss |
| | | (PM/Loss) |
| 4 | D | Performance Measurement/Delay |
| | | (PM/Delay) |
| 5 | T | Throughput Measurement) |
| 6-31 | | Reserved |
+------------+--------------------+---------------------------------+
Table 1: MPLS OAM TLV Flags
Sub-TLVs corresponding to the different flags are as follows:
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- BFD Configuration sub-TLV, which MUST be included if the CC and/
or the CV OAM Function flag is set. This sub-TLV MUST carry a
"BFD Local Discriminator sub-TLV" and a "Timer Negotiation
Parameters sub-TLV" if the N flag is cleared. The "Source MEP-ID
sub-TLV" MUST also be included. If the I flag is set, the "BFD
Authentication sub-TLV" may be included.
- PM Loss sub-TLV within the "Performance Monitoring sub-TLV",
which MAY be included if the PM/Loss OAM Function flag is set. If
the "PM Loss sub-TLV" is not included, default configuration
values are used. Such sub-TLV MAY also be included in case the
Throughput function flag is set and there is the need to specify
measurement interval different from the default ones. In fact the
throughput measurement make use of the same tool as the loss
measurement, hence the same TLV is used.
- PM Delay sub-TLV within the "Performance Monitoring sub-TLV",
which MAY be included if the PM/Delay OAM Function flag is set.
If the "PM Delay sub-TLV" is not included, default configuration
values are used.
- FMS sub-TLV, which MAY be included if the FMS OAM Function flag
is set. If the "FMS sub-TLV" is not included, default
configuration values are used.
2.2.1. BFD Configuration sub-TLV
The BFD Configuration sub-TLV, depicted Figure 2, is defined for BFD
OAM specific configuration parameters. The "BFD Configuration sub-
TLV" is carried as a sub-TLV of the "OAM Functions TLV".
This TLV accommodates generic BFD OAM information and carries sub-
TLVs.
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| BFD Conf. sub-Type (100) | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|Vers.| PHB |N|S|I|G|U|B| Reserved (set to all 0s) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 2: BFD Configuration sub-TLV format
Sub-type: indicates a new sub-type, the BFD Configuration sub-TLV
(IANA to define, suggested value 100).
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Length: indicates the length of the TLV including sub-TLVs but
excluding the Type and Length field, in octets.
Version: identifies the BFD protocol version. If a node does not
support a specific BFD version an error must be generated: "OAM
Problem/Unsupported OAM Version".
PHB: Identifies the Per-Hop Behavior (PHB) to be used for periodic
continuity monitoring messages.
BFD Negotiation (N): If set timer negotiation/re-negotiation via BFD
Control Messages is enabled, when cleared it is disabled.
Symmetric session (S): If set the BFD session MUST use symmetric
timing values.
Integrity (I): If set BFD Authentication MUST be enabled. If the BFD
Configuration sub-TLV does not include a BFD Authentication sub-TLV
the authentication MUST use Keyed SHA1 with an empty pre-shared key
(all 0s).
Encapsulation Capability (G): if set, it shows the capability of
encapsulating BFD messages into G-ACh channel. If both the G bit and
U bit are set, configuration gives precedence to the G bit.
Encapsulation Capability (U): if set, it shows the capability of
encapsulating BFD messages into IP/UDP packets. If both the G bit
and U bit are set, configuration gives precedence to the G bit.
Bidirectional (B): if set, it configures BFD in the Bidirectional
mode. If it is not set it configures BFD in unidirectional mode. In
the second case, the source node does not expect any Discriminator
values back from the destination node.
Reserved: Reserved for future specification and set to 0 on
transmission and ignored when received.
The BFD Configuration sub-TLV MUST include the following sub-TLVs in
the LSP Echo request message:
- Local Discriminator sub-TLV;
- Negotiation Timer Parameters sub-TLV if the N flag is cleared.
The BFD Configuration sub-TLV MUST include the following sub-TLVs in
the LSP Echo reply message:
- Local Discriminator sub-TLV;
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- Negotiation Timer Parameters sub-TLV if:
- the N and S flags are cleared, or if:
- the N flag is cleared and the S flag is set, and the
Negotiation Timer Parameters sub-TLV received by the egress
contains unsupported values. In this case an updated
Negotiation Timer Parameters sub-TLV, containing values
supported by the egress node, is returned to the ingress.
2.2.2. Local Discriminator sub-TLV
The Local Discriminator sub-TLV is carried as a sub-TLV of the "BFD
Configuration sub-TLV" and is depicted in Figure 3.
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Lcl. Discr. sub-Type (101) | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Local Discriminator |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 3: Local Discriminator sub-TLV format
Type: indicates a new type, the "Local Discriminator sub-TLV" (IANA
to define, suggested value 101).
Length: indicates the sub-TLV length in octets, excluding the sub-
type and Length field. (4)
Local Discriminator: A unique, nonzero discriminator value generated
by the transmitting system and referring to itself, used to
demultiplex multiple BFD sessions between the same pair of systems.
2.2.3. Negotiation Timer Parameters sub-TLV
The Negotiation Timer Parameters sub-TLV is carried as a sub-TLV of
the BFD Configuration sub-TLV and is depicted in Figure 4.
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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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Nego. Timer sub-type (102) | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Acceptable Min. Asynchronous TX interval |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Acceptable Min. Asynchronous RX interval |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Required Echo TX Interval |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 4: Negotiation Timer Parameters sub-TLV format
Sub-type: indicates a new sub-type, the Negotiation Timer Parameters
sub-TLV (IANA to define, suggested value 102).
Length: indicates the length of the parameters in octets (12).
Acceptable Min. Asynchronous TX interval: in case of S (symmetric)
flag set in the BFD Configuration sub-TLV, defined in Section 2.2.1,
it expresses the desired time interval (in microseconds) at which the
ingress LER intends to both transmit and receive BFD periodic control
packets. If the receiving edge LSR can not support such value, it
SHOULD reply with an interval greater than the one proposed.
In case of S (symmetric) flag cleared in the BFD Configuration sub-
TLV, this field expresses the desired time interval (in microseconds)
at which a edge LSR intends to transmit BFD periodic control packets
in its transmitting direction.
Acceptable Min. Asynchronous RX interval: in case of S (symmetric)
flag set in the BFD Configuration sub-TLV, Figure 2, this field MUST
be equal to Acceptable Min. Asynchronous TX interval and has no
additional meaning respect to the one described for "Acceptable Min.
Asynchronous TX interval".
In case of S (symmetric) flag cleared in the BFD Configuration sub-
TLV, it expresses the minimum time interval (in microseconds) at
which edge LSRs can receive BFD periodic control packets. In case
this value is greater than the value of Acceptable Min. Asynchronous
TX interval received from the other edge LSR, such edge LSR MUST
adopt the interval expressed in this Acceptable Min. Asynchronous RX
interval.
Required Echo TX Interval: the minimum interval (in microseconds)
between received BFD Echo packets that this system is capable of
supporting, less any jitter applied by the sender as described in
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[RFC5880] sect. 6.8.9. This value is also an indication for the
receiving system of the minimum interval between transmitted BFD Echo
packets. If this value is zero, the transmitting system does not
support the receipt of BFD Echo packets. If the receiving system can
not support this value the "Unsupported BFD TX Echo rate interval"
error MUST be generated. By default the value is set to 0.
2.2.4. BFD Authentication sub-TLV
The "BFD Authentication sub-TLV" is carried as a sub-TLV of the "BFD
Configuration sub-TLV" and is depicted in Figure 5.
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| BFD Auth. sub-type (103) | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Auth Type | Auth Key ID | Reserved (0s) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 5: BFD Authentication sub-TLV format
Sub-type: indicates a new type, the BFD Authentication sub-TLV (IANA
to define, suggested value 103).
Length: indicates the TLV total length in octets, exluding the Type
and Length fields. (4)
Auth Type: indicates which type of authentication to use. The same
values as are defined in section 4.1 of [RFC5880] are used.
Auth Key ID: indicates which authentication key or password
(depending on Auth Type) should be used. How the key exchange is
performed is out of scope of this document.
Reserved: Reserved for future specification and set to 0 on
transmission and ignored when received.
2.2.5. Performance Measurement sub-TLV
If the MPLS OAM Functions TLV has either the L (Loss), D (Delay) or T
(Throughput) flag set, the Performance Measurement sub-TLV MUST be
present.
The Performance Measurement sub-TLV provides the configuration
information mentioned in Section 7 of [RFC6374]. It includes support
for the configuration of quality thresholds and, as described in
[RFC6374], "the crossing of which will trigger warnings or alarms,
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and result reporting and exception notification will be integrated
into the system-wide network management and reporting framework."
In case the values need to be different than the default ones the
Performance Measurement sub-TLV MAY include the following sub-TLVs:
- PM Loss sub-TLV if the L flag is set in the MPLS OAM Functions
TLV;
- PM Delay sub-TLV if the D flag is set in the MPLS OAM Functions
TLV.
The Performance Measurement sub-TLV depicted in Figure 6 is carried
as a sub-TLV of the MPLS OAM Functions TLV.
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Perf Monitoring Type (200) | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|D|L|J|Y|K|C| Reserved (set to all 0s) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 6: Performance Measurement sub-TLV format
Sub-type: indicates a new sub-type, the Performance Management sub-
TLV" (IANA to define, suggested value 200).
Length: indicates the TLV length in octets, exluding the Type and
Length fields.
Configuration Flags, for the specific function description please
refer to [RFC6374]:
- D: Delay inferred/direct (0=INFERRED, 1=DIRECT)
- L: Loss inferred/direct (0=INFERRED, 1=DIRECT)
- J: Delay variation/jitter (1=ACTIVE, 0=NOT ACTIVE)
- Y: Dyadic (1=ACTIVE, 0=NOT ACTIVE)
- K: Loopback (1=ACTIVE, 0=NOT ACTIVE)
- C: Combined (1=ACTIVE, 0=NOT ACTIVE)
Reserved: Reserved for future specification and set to 0 on
transmission and ignored when received.
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2.2.6. PM Loss Measurement sub-TLV
The PM Loss Measurement sub-TLV depicted in Figure 7 is carried as a
sub-TLV of the Performance Measurement sub-TLV.
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| PM Loss sub-type (201) | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| OTF |T|B| Reserved (set to all 0s) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Measurement Interval |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Test Interval |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Loss Threshold |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 7: PM Loss Measurement sub-TLV format
Sub-type: indicates a new sub-type, the PM Loss Measurement sub-TLV
(IANA to define, suggested value 201).
Length: indicates the length of the parameters in octets (16).
OTF: Origin Timestamp Format of the Origin Timestamp field described
in [RFC6374]. By default it is set to IEEE 1588 version 1.
Configuration Flags, please refer to [RFC6374] for further details:
- T: Traffic-class-specific measurement indicator. Set to 1 when
the measurement operation is scoped to packets of a particular
traffic class (DSCP value), and 0 otherwise. When set to 1, the
DS field of the message indicates the measured traffic class. By
default it is set to 1.
- B: Octet (byte) count. When set to 1, indicates that the
Counter 1-4 fields represent octet counts. When set to 0,
indicates that the Counter 1-4 fields represent packet counts. By
default it is set to 0.
Reserved: Reserved for future specification and set to 0 on
transmission and ignored when received.
Measurement Interval: the time interval (in milliseconds) at which
Loss Measurement query messages MUST be sent on both directions. If
the edge LSR receiving the Path message can not support such value,
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it SHOULD reply with a higher interval. By default it is set to
(100) as per [RFC6375].
Test Interval: test messages interval in milliseconds as described in
[RFC6374]. By default it is set to (10) as per [RFC6375].
Loss Threshold: the threshold value of measured lost packets per
measurement over which action(s) SHOULD be triggered.
2.2.7. PM Delay Measurement sub-TLV
The PM Delay Measurement sub-TLV" depicted in Figure 8 is carried as
a sub-TLV of the Performance Monitoring sub-TLV.
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| PM Delay Type (202) | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| OTF |T|B| Reserved (set to all 0s) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Measurement Interval |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Test Interval |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Delay Threshold |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 8: PM Delay Measurement sub-TLV format
Sub-type: indicates a new sub-type, the PM Delay Measurement sub-TLV"
(IANA to define, suggested value 202).
Length: indicates the length of the parameters in octets (16).
OTF: Origin Timestamp Format of the Origin Timestamp field described
in [RFC6374]. By default it is set to IEEE 1588 version 1.
Configuration Flags, please refer to [RFC6374] for further details:
- T: Traffic-class-specific measurement indicator. Set to 1 when
the measurement operation is scoped to packets of a particular
traffic class (DSCP value), and 0 otherwise. When set to 1, the
DS field of the message indicates the measured traffic class. By
default it is set to 1.
- B: Octet (byte) count. When set to 1, indicates that the
Counter 1-4 fields represent octet counts. When set to 0,
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indicates that the Counter 1-4 fields represent packet counts. By
default it is set to 0.
Reserved: Reserved for future specification and set to 0 on
transmission and ignored when received.
Measurement Interval: the time interval (in milliseconds) at which
Delay Measurement query messages MUST be sent on both directions. If
the edge LSR receiving the Path message can not support such value,
it can reply with a higher interval. By default it is set to (1000)
as per [RFC6375].
Test Interval: test messages interval (in milliseconds) as described
in [RFC6374]. By default it is set to (10) as per [RFC6375].
Delay Threshold: the threshold value of measured two-way delay (in
milliseconds) over which action(s) SHOULD be triggered.
2.2.8. Fault Managemet Signal sub-TLV
The FMS sub-TLV depicted in Figure 9 is carried as a sub-TLV of the
MPLS OAM Configuration sub-TLV. When both working and protection
paths are configured, both LSPs SHOULD be configured with identical
settings of the E flag, T flag, and the refresh timer.
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| FMS sub-type (300) | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|E|S|T| Reserved (set to all 0s)| Refresh Timer | PHB |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 9: Fault Management Signal sub-TLV format
Sub-type: indicates a new sub-type, the FMS sub-TLV (IANA to define,
suggested value 300).
Length: indicates the length of the parameters in octets (4).
FMS Signal Flags are used to enable the FMS signals at end point MEPs
and the Server MEPs of the links over which the LSP is forwarded. In
this document only the S flag pertains to Server MEPs.
The following flags are defined:
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- E: Enable Alarm Indication Signal (AIS) and Lock Report (LKR)
signalling as described in [RFC6427]. Default value is 1
(enabled).
- S: Indicate to a server MEP that its should transmit AIS and LKR
signals on the client LSP. Default value is 0 (disabled).
- T: Set timer value, enabled the configuration of a specific
timer value. Default value is 0 (disabled).
- Remaining bits: Reserved for future specification and set to 0.
Refresh Timer: indicates the refresh timer of fault indication
messages, in seconds. The value MUST be between 1 to 20 seconds as
specified for the Refresh Timer field in [RFC6427]. If the edge LSR
receiving the Path message can not support the value it SHOULD reply
with a higher timer value.
PHB: identifies the per-hop behavior of packets with fault management
information.
2.2.9. Source MEP-ID sub-TLV
The Source MEP-ID sub-TLV depicted in Figure 10 is carried as a sub-
TLV of the MPLS OAM Functions TLV.
Note that support of ITU IDs is out-of-scope.
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Source MEP-ID sub-type (400) | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Source Node ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tunnel ID | LSP ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 10: Source MEP-ID sub-TLV format
Sub-type: indicates a new sub-type, the Source MEP-ID sub-TLV (IANA
to define, suggested value 400).
Length: indicates the length of the TLV in octets, excluding the Type
and Length fields. (8)
Source Node ID: 32-bit node identifier as defined in [RFC6370].
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Tunnel ID: a 16-bit unsigned integer unique to the node as defined in
[RFC6370].
LSP ID: a 16-bit unsigned integer unique within the Tunnel_ID as
defined in [RFC6370].
3. IANA Considerations
3.1. TLV and sub-TLV Allocation
Note: The IANA considerations in this document is written according
to the allocation policies specified in RFC4379. However there is a
draft that suggest changes to these allocation policies, draft-pac-
mpls-lsp-ping-tlvs-and-sub-tlvs-registry if the working group accept
the new allocation specied in that draft the allocations made this
draft, this IANA Considerations section in this document will be re-
written.
IANA maintians a registry Multi-Protocol Label Switching (MPLS) Label
Switched Paths (LSPs) Ping Parameters registry, and within that
registry a sub-registry TLVs and sub-TLVs.
IANA is requested a new TLV from the standards action range (0-16383)
and sub-TLVs as follows from this sub-registry.
+------+----------+---------------------------------+---------------+
| Type | Sub-type | Value Field | Reference |
+------+----------+---------------------------------+---------------+
| TBD1 | | MPLS OAM Functions | This document |
| | 100 | BFD Configuration | This document |
| | 101 | BFD Local Discriminator | This document |
| | 102 | BFD Negotiation Timer | This document |
| | | Parameters | |
| | 103 | BFD Authentication | This document |
| | 200 | Performance Measurement | This document |
| | 201 | PM Loss Measurement | This document |
| | 202 | PM Delay Measurement | This document |
| | 203 | Fault Management Signal | This document |
| | 204 | Source MEP-ID | This document |
+------+----------+---------------------------------+---------------+
Table 2: IANA TLV Type Allocation
3.2. OAM configuration errors
IANA maintians a registry "Multi-Protocol Label Switching (MPLS)
Label Switched Paths (LSPs) Ping Parameters" registry, and within
that registry a sub-registry "Return Codes".
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IANA is requested to assign new Return Codes from the Standards
Action range (0-191) as follows:
+-------+-------------------------------------------+---------------+
| Value | Meaning | Reference |
+-------+-------------------------------------------+---------------+
| TBD2 | MPLS OAM Unsupported Functionality | This document |
| TBD3 | OAM Problem/Unsupported TX rate interval | This document |
| TBD4 | OAM Problem/Unsupported RX rate interval | This document |
| TBD5 | OAM Problem/Unsupported Authentication | This document |
| | Type | |
| TBD6 | OAM Problem mismatch of Authentication | This document |
| | Key ID | |
+-------+-------------------------------------------+---------------+
Table 3: IANA Return Codes Allocation
4. Security Considerations
The signaling of OAM related parameters and the automatic
establishment of OAM entities introduces additional security
considerations to those discussed in [RFC3473]. In particular, a
network element could be overloaded if an attacker were to request
high frequency liveliness monitoring of a large number of LSPs,
targeting a single network element.
5. References
5.1. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC3473] Berger, L., "Generalized Multi-Protocol Label Switching
(GMPLS) Signaling Resource ReserVation Protocol-Traffic
Engineering (RSVP-TE) Extensions", RFC 3473, January 2003.
[RFC4379] Kompella, K. and G. Swallow, "Detecting Multi-Protocol
Label Switched (MPLS) Data Plane Failures", RFC 4379,
February 2006.
[RFC5654] Niven-Jenkins, B., Brungard, D., Betts, M., Sprecher, N.,
and S. Ueno, "Requirements of an MPLS Transport Profile",
RFC 5654, September 2009.
[RFC5860] Vigoureux, M., Ward, D., and M. Betts, "Requirements for
Operations, Administration, and Maintenance (OAM) in MPLS
Transport Networks", RFC 5860, May 2010.
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[RFC5880] Katz, D. and D. Ward, "Bidirectional Forwarding Detection
(BFD)", RFC 5880, June 2010.
[RFC5884] Aggarwal, R., Kompella, K., Nadeau, T., and G. Swallow,
"Bidirectional Forwarding Detection (BFD) for MPLS Label
Switched Paths (LSPs)", RFC 5884, June 2010.
[RFC6370] Bocci, M., Swallow, G., and E. Gray, "MPLS Transport
Profile (MPLS-TP) Identifiers", RFC 6370, September 2011.
[RFC6374] Frost, D. and S. Bryant, "Packet Loss and Delay
Measurement for MPLS Networks", RFC 6374, September 2011.
[RFC6427] Swallow, G., Fulignoli, A., Vigoureux, M., Boutros, S.,
and D. Ward, "MPLS Fault Management Operations,
Administration, and Maintenance (OAM)", RFC 6427, November
2011.
[RFC6428] Allan, D., Swallow Ed. , G., and J. Drake Ed. , "Proactive
Connectivity Verification, Continuity Check, and Remote
Defect Indication for the MPLS Transport Profile", RFC
6428, November 2011.
5.2. Informative References
[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.
[RFC5036] Andersson, L., Minei, I., and B. Thomas, "LDP
Specification", RFC 5036, October 2007.
[RFC6371] Busi, I. and D. Allan, "Operations, Administration, and
Maintenance Framework for MPLS-Based Transport Networks",
RFC 6371, September 2011.
[RFC6375] Frost, D. and S. Bryant, "A Packet Loss and Delay
Measurement Profile for MPLS-Based Transport Networks",
RFC 6375, September 2011.
[RFC6669] Sprecher, N. and L. Fang, "An Overview of the Operations,
Administration, and Maintenance (OAM) Toolset for MPLS-
Based Transport Networks", RFC 6669, July 2012.
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[RSVP-TE-CONF]
Bellagamba, E., Andersson, L., Ward, D., and P.
Skoldstrom, "Configuration of pro-active MPLS-TP
Operations, Administration, and Maintenance (OAM)
Functions Using RSVP-TE", 2012, <draft-ietf-ccamp-rsvp-te-
mpls-tp-oam-ext>.
Authors' Addresses
Elisa Bellagamba (editor)
Ericsson
Email: elisa.bellagamba@ericsson.com
Gregory Mirsky (editor)
Ericsson
Email: Gregory.Mirsky@ericsson.com
Loa Andersson
Huawei
Email: loa@mail01.huawei.com
Pontus Skoldstrom (editor)
Acreo AB
Electrum 236
Kista 164 40
Sweden
Phone: +46 8 6327731
Email: pontus.skoldstrom@acreo.se
Dave Ward
Cisco
Email: dward@cisco.com
John Drake
Juniper
Email: jdrake@juniper.net
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