Network Working Group R. Papneja
Internet Draft Isocore
Intended Status: Informational
Expires: April 2010 S. Vapiwala
J. Karthik
Cisco Systems
S. Poretsky
Allot Communications
S. Rao
Qwest Communications
J.L. Le Roux
France Telecom
October 2009
Methodology for benchmarking MPLS protection mechanisms
draft-ietf-bmwg-protection-meth-06.txt
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Abstract
This draft describes the methodology for benchmarking MPLS
Protection mechanisms for link and node protection as defined in
[MPLS-FRR-EXT]. This document provides test methodologies and
testbed setup for measuring failover times while considering
all dependencies that might impact faster recovery of real-time
applications bound to MPLS based traffic engineered tunnels.
The benchmarking terms used in this document are defined in
[TERM-ID].
Table of Contents
1. Introduction...................................................3
2. Document Scope.................................................4
3. Existing definitions...........................................5
4. General Reference Topology.....................................5
5. Test Considerations............................................6
5.1. Failover Events..............................................6
5.2. Failure Detection............................................7
5.3. Use of Data Traffic for MPLS Protection Benchmarking.........7
5.4. LSP and Route Scaling........................................8
5.5. Selection of IGP.............................................8
5.6. Reversion....................................................8
5.7. Offered Load.................................................8
5.8. Tester Capabilities..........................................9
6. Reference Test Setups..........................................9
6.1 Link Protection...............................................9
6.2 Node Protection..............................................13
7. Test Methodologies............................................15
7.1. MPLS FRR Forwarding Performance Test Cases..................15
7.2. Headend PLR with link failure...............................17
7.3. Mid-Point PLR with link failure.............................18
7.4. Headend PLR with Node Failure...............................19
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7.5. Mid-Point PLR with Node Failure.............................21
8. Reporting Format..............................................23
9. Security Considerations.......................................24
10. IANA Considerations..........................................24
11. References...................................................24
11.1. Normative References.......................................24
11.2. Informative References.....................................24
12. Acknowledgments..............................................24
Author's Addresses...............................................25
Appendix A: Fast Reroute Scalability Table.......................26
Appendix B: Abbreviations........................................38
1. Introduction
This draft describes the methodology for benchmarking MPLS based
protection mechanisms. The new terminology that this document
introduces is defined in [TERM-ID].
MPLS based protection mechanisms provide fast recovery of real-time
services from a planned or an unplanned link or node failures.
MPLS protection mechanisms are generally deployed in a network
infrastructure where MPLS is used for provisioning of point-to-
point traffic engineered tunnels (tunnel). MPLS based protection
mechanisms promise to improve service disruption period by
minimizing recovery time from most common failures.
Network elements from different manufacturers behave differently to
network failures, which impacts the network's ability and
performance for failure recovery. It therefore becomes imperative
for service providers to have a common benchmark to understand the
performance behaviors of network elements.
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There are two factors impacting service availability:
frequency of failures and duration for which the failures persist.
Failures can be classified further into two types: correlated and
uncorrelated. Correlated and uncorrelated failures may be planned
or unplanned.
Planned failures are predictable. Network implementations should
be able to handle both planned and unplanned failures and recover
gracefully within a time frame to maintain service assurance.
Hence, failover recovery time is one of the most important benchmark
that a service provider considers in choosing the building blocks
for their network infrastructure.
A correlated failure is the simultaneous occurrence
of two or more failures. A typical example is failure of a logical
resource (e.g. layer-2 links) due to a dependency on a common
physical resource (e.g. common conduit) that fails. Within
the context of MPLS protection mechanisms, failures that arise due
to Shared Risk Link Groups (SRLG) [MPLS-FRR-EXT] can be considered
as correlated failures. Not all correlated failures are
predictable in advance, for example, those caused by natural
disasters.
2. Document Scope
This document provides detailed test cases along with different
topologies and scenarios that should be considered to effectively
benchmark MPLS protection mechanisms and failover times on the
Data Plane. Different Failover Events and scaling considerations
are also provided in this document.
All benchmarking testcases defined in this document apply to both
facility backup and local protection enabled in detour mode. The
test cases cover all possible failure scenarios and the
associated procedures benchmark the performance of the Device
Under Test (DUT) to recover from failures. Data plane traffic is
used to benchmark failover times.
Benchmarking of correlated failures is out of scope of this
document. Protection from Bi-directional Forwarding Detection
(BFD) is outside the scope of this document.
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3. Existing definitions
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 BCP 14, RFC 2119
[Br97]. RFC 2119 defines the use of these key words to help make the
intent of standards track documents as clear as possible. While this
document uses these keywords, this document is not a standards track
document.
The reader is assumed to be familiar with the commonly used MPLS
terminology, some of which is defined in [MPLS-FRR-EXT].
This document uses much of the terminology defined in
[TERM-ID]. This document also uses existing terminology defined
in other BMWG work. Examples include, but are not limited to:
Throughput [Ref.[Br91], section 3.17]
Device Under Test (DUT) [Ref.[Ma98], section 3.1.1]
System Under Test (SUT) [Ref.[Ma98], section 3.1.2]
Out-of-order Packet [Ref.[Po06], section 3.3.2]
Duplicate Packet [Ref.[Po06], section 3.3.3]
4. General Reference Topology
Figure 1 illustrates the basic reference testbed and is applicable
to all the test cases defined in this document. The Tester is
comprised of a Traffic Generator (TG) & Test Analyzer (TA). A
Tester is directly connected to the DUT. The Tester sends and
receives IP traffic to the tunnel ingress and performs signaling
protocol emulation to simulate real network scenarios in a lab
environment. The Tester may also support MPLS-TE signaling to act
as the ingress node to the MPLS tunnel.
---------------------------
| ------------|---------------
| | | |
| | | |
-------- -------- -------- -------- --------
TG--| R1 |-----| R2 |----| R3 | | R4 | | R5 |
| |-----| |----| |----| |---| |
-------- -------- -------- -------- --------
| | | | |
| | | | |
| -------- | | TA
---------| R6 |--------- |
| |----------------------
--------
Fig.1: Fast Reroute Topology.
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The tester MUST record the number of lost, duplicate, and reordered
packets. It should further record arrival and departure times so
that Failover Time, Additive Latency, and Reversion Time can be
measured. The tester may be a single device or a test system
emulating all the different roles along a primary or backup path.
The label stack is dependent of the following 3 entities:
- Type of protection (Link Vs Node)
- # of remaining hops of the primary tunnel from the PLR
- # of remaining hops of the backup tunnel from the PLR
Due to this dependency, it is RECOMMENDED that the benchmarking of
failover times be performed on all the topologies provided in
section 6.
5. Test Considerations
This section discusses the fundamentals of MPLS Protection testing:
-The types of network events that causes failover
-Indications for failover
-the use of data traffic
-Traffic generation
-LSP Scaling
-Reversion of LSP
-IGP Selection
5.1. Failover Events [TERM-ID]
The failover to the backup tunnel is primarily triggered by either
link or node failures observed downstream of the Point of Local
repair (PLR). Some of these failure events are listed below.
Link failure events
- Interface Shutdown on PLR side with POS Alarm
- Interface Shutdown on remote side with POS Alarm
- Interface Shutdown on PLR side with RSVP hello enabled
- Interface Shutdown on remote side with RSVP hello enabled
- Interface Shutdown on PLR side with BFD
- Interface Shutdown on remote side with BFD
- Fiber Pull on the PLR side (Both TX & RX or just the TX)
- Fiber Pull on the remote side (Both TX & RX or just the RX)
- Online insertion and removal (OIR) on PLR side
- OIR on remote side
- Sub-interface failure (e.g. shutting down of a VLAN)
- Parent interface shutdown (an interface bearing multiple sub-
interfaces
Node failure events
- A System reload initiated either by a graceful shutdown or by
a power failure.
- A system crash due to a software failure or an assert.
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5.2. Failure Detection [TERM-ID]
Link failure detection time depends on the link type and failure
detection protocols running. For SONET/SDH, the alarm type (such as
LOS, AIS, or RDI) can be used. Other link types have layer-two
alarms, but they may not provide a short enough failure detection
time. Ethernet based links do not have layer 2 failure indicators,
and therefore relies on layer 3 signaling for failure detection.
However for directly connected devices, remote fault indication in
the ethernet auto-negotiation scheme could be considered as a type
of layer 2 link failure indicator.
MPLS has different failure detection techniques such as BFD, or use
of RSVP hellos. These methods can be used for the layer 3 failure
indicators required by Ethernet based links, or for some other non-
Ethernet based links to help improve failure detection time.
The test procedures in this document can be used for a local failure
or remote failure scenarios for comprehensive benchmarking and to
evaluate failover performance independent of the failure detection
techniques.
5.3. Use of Data Traffic for MPLS Protection benchmarking
Currently end customers use packet loss as a key metric for
Failover Time [TERM-ID]. Failover Packet Loss [TERM-ID] is an
externally observable event and has direct impact on application
performance. MPLS protection is expected to minimize the packet
loss in the event of a failure. For this reason it is important to
develop a standard router benchmarking methodology for measuring
MPLS protection that uses packet loss as a metric. At a known rate
of forwarding, packet loss can be measured and the failover time
can be determined. Measurement of control plane signaling to
establish backup paths is not enough to verify failover. Failover
is best determined when packets are actually traversing the backup
path.
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An additional benefit of using packet loss for calculation of
failover time is that it allows use of a black-box test environment.
Data traffic is offered at line-rate to the device under test (DUT)
an emulated network failure event is forced to occur, and packet loss
is externally measured to calculate the convergence time. This setup
is independent of the DUT architecture.
In addition, this methodology considers the packets in error and
duplicate packets that could have been generated during the failover
process. The methodologies consider lost, out-of-order, and
duplicate packets to be impaired packets that contribute to the
Failover Time.
5.4. LSP and Route Scaling
Failover time performance may vary with the number of established
primary and backup tunnel label switched paths (LSP) and installed
routes. However the procedure outlined here should be used for
any number of LSPs (L) and number of routes protected by PLR(R).
The amount of L and R must be recorded.
5.5. Selection of IGP
The underlying IGP could be ISIS-TE or OSPF-TE for the methodology
proposed here. See [IGP-METH] for IGP options to consider and
report.
5.6. Restoration and Reversion [TERM-ID]
Fast Reroute provides a method to return or restore an original
primary LSP upon recovery from the failure (Restoration) and to
switch traffic from the Backup Path to the restored Primary Path
(Reversion). In MPLS-FRR, Reversion can be implemented as Global
Reversion or Local Reversion. It is important to include
Restoration and Reversion as a step in each test case to measure
the amount of packet loss, out of order packets, or duplicate
packets that is produced.
5.7. Offered Load
It is suggested that there be one or more traffic streams as long as
there is a steady and constant rate of flow for all the streams. In
order to monitor the DUT performance for recovery times, a set of
route prefixes should be advertised before traffic is sent. The
traffic should be configured towards these routes.
A typical example would be configuring the traffic generator to send
the traffic to the first, middle and last of the advertised routes.
(First, middle and last could be decided by the numerically
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smallest, median and the largest respectively of the advertised
prefix). Generating traffic to all of the prefixes reachable by the
protected tunnel (probably in a Round-Robin fashion, where the
traffic is destined to all the prefixes but one prefix at a time in
a cyclic manner) is not recommended. The reason why traffic
generation is not recommended in a Round-Robin fashion to all the
prefixes, one at a time is that if there are many prefixes reachable
through the LSP the time interval between 2 packets destined to one
prefix may be significantly high and may be comparable with the
failover time being measured which does not aid in getting an
accurate failover measurement.
5.8 Tester Capabilities
It is RECOMMENDED that the Tester used to execute each test case
have the following capabilities:
1. Ability to establish MPLS-TE tunnels and push/pop labels.
2. Ability to produce Failover Event [TERM-ID].
3. Ability to insert a timestamp in each data packet's IP
payload.
4. An internal time clock to control timestamping, time
measurements, and time calculations.
5. Ability to disable or tune specific Layer-2 and Layer-3
protocol functions on any interface(s).
The Tester MAY be capable to make non-data plane convergence
observations and use those observations for measurements.
6. Reference Test Setup
In addition to the general reference topology shown in figure 1,
this section provides detailed insight into various proposed test
setups that should be considered for comprehensively benchmarking
the failover time in different roles along the primary tunnel:
This section proposes a set of topologies that covers all the
scenarios for local protection. All of these topologies can be
mapped to the reference topology shown in Figure 1. Topologies
provided in this section refer to the testbed required to
benchmark failover time when the DUT is configured as a PLR in
either Headend or midpoint role. Provided with each topology
below is the label stack at the PLR. Penultimate Hop
Popping (PHP) MAY be used and must be reported when used.
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Figures 2 thru 9 use the following convention:
a) HE is Headend
b) TE is Tail-End
c) MID is Mid point
d) MP is Merge Point
e) PLR is Point of Local Repair
f) PRI is Primary Path
g) BKP denotes Backup Path and Nodes
6.1. Link Protection
6.1.1 Link Protection - 1 hop primary (from PLR) and 1 hop backup TE
tunnels
------- -------- PRI --------
| R1 | | R2 | | R3 |
TG-| HE |--| MID |----| TE |-TA
| | | PLR |----| |
------- -------- BKP --------
Figure 2.
Traffic Num of Labels Num of labels
before failure after failure
IP TRAFFIC (P-P) 0 0
Layer3 VPN (PE-PE) 1 1
Layer3 VPN (PE-P) 2 2
Layer2 VC (PE-PE) 1 1
Layer2 VC (PE-P) 2 2
Mid-point LSPs 0 0
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6.1.2. Link Protection - 1 hop primary (from PLR) and 2 hop backup TE
tunnels
------- -------- --------
| R1 | | R2 | | R3 |
TG-| HE | | MID |PRI | TE |-TA
| |----| PLR |----| |
------- -------- --------
|BKP |
| -------- |
| | R6 | |
|----| BKP |----|
| MID |
--------
Figure 3.
Traffic Num of Labels Num of labels
before failure after failure
IP TRAFFIC (P-P) 0 1
Layer3 VPN (PE-PE) 1 2
Layer3 VPN (PE-P) 2 3
Layer2 VC (PE-PE) 1 2
Layer2 VC (PE-P) 2 3
Mid-point LSPs 0 1
6.1.3. Link Protection - 2+ hop (from PLR) primary and 1 hop backup TE
tunnels
-------- -------- -------- --------
| R1 | | R2 |PRI | R3 |PRI | R4 |
TG-| HE |----| MID |----| MID |------| TE |-TA
| | | PLR |----| | | |
-------- -------- BKP -------- --------
Figure 4.
Traffic Num of Labels Num of labels
before failure after failure
IP TRAFFIC (P-P) 1 1
Layer3 VPN (PE-PE) 2 2
Layer3 VPN (PE-P) 3 3
Layer2 VC (PE-PE) 2 2
Layer2 VC (PE-P) 3 3
Mid-point LSPs 1 1
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6.1.4. Link Protection - 2+ hop (from PLR) primary and 2 hop backup TE
tunnels
-------- -------- PRI -------- PRI --------
| R1 | | R2 | | R3 | | R4 |
TG-| HE |----| MID |----| MID |------| TE |-TA
| | | PLR | | | | |
-------- -------- -------- --------
BKP| |
| -------- |
| | R6 | |
---| BKP |-
| MID |
--------
Figure 5.
Traffic Num of Labels Num of labels
before failure after failure
IP TRAFFIC (P-P) 1 2
Layer3 VPN (PE-PE) 2 3
Layer3 VPN (PE-P) 3 4
Layer2 VC (PE-PE) 2 3
Layer2 VC (PE-P) 3 4
Mid-point LSPs 1 2
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6.2. Node Protection
6.2.1. Node Protection - 2 hop primary (from PLR) and 1 hop backup TE
tunnels
-------- -------- -------- --------
| R1 | | R2 |PRI | R3 | PRI | R4 |
TG-| HE |----| MID |----| MID |------| TE |-TA
| | | PLR | | | | |
-------- -------- -------- --------
|BKP |
-----------------------------
Figure 6.
Traffic Num of Labels Num of labels
before failure after failure
IP TRAFFIC (P-P) 1 0
Layer3 VPN (PE-PE) 2 1
Layer3 VPN (PE-P) 3 2
Layer2 VC (PE-PE) 2 1
Layer2 VC (PE-P) 3 2
Mid-point LSPs 1 0
6.2.2. Node Protection - 2 hop primary (from PLR) and 2 hop backup TE
tunnels
-------- -------- -------- --------
| R1 | | R2 | | R3 | | R4 |
TG-| HE | | MID |PRI | MID |PRI | TE |-TA
| |----| PLR |----| |----| |
-------- -------- -------- --------
| |
BKP| -------- |
| | R6 | |
---------| BKP |---------
| MID |
--------
Figure 7.
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Traffic Num of Labels Num of labels
before failure after failure
IP TRAFFIC (P-P) 1 1
Layer3 VPN (PE-PE) 2 2
Layer3 VPN (PE-P) 3 3
Layer2 VC (PE-PE) 2 2
Layer2 VC (PE-P) 3 3
Mid-point LSPs 1 1
6.2.3. Node Protection - 3+ hop primary (from PLR) and 1 hop backup TE
tunnels
-------- -------- PRI -------- PRI -------- PRI --------
| R1 | | R2 | | R3 | | R4 | | R5 |
TG-| HE |--| MID |---| MID |---| MP |---| TE |-TA
| | | PLR | | | | | | |
-------- -------- -------- -------- --------
BKP| |
--------------------------
Figure 8.
Traffic Num of Labels Num of labels
before failure after failure
IP TRAFFIC (P-P) 1 1
Layer3 VPN (PE-PE) 2 2
Layer3 VPN (PE-P) 3 3
Layer2 VC (PE-PE) 2 2
Layer2 VC (PE-P) 3 3
Mid-point LSPs 1 1
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6.2.4. Node Protection - 3+ hop primary (from PLR) and 2 hop backup TE
tunnels
-------- -------- -------- -------- --------
| R1 | | R2 | | R3 | | R4 | | R5 |
TG-| HE | | MID |PRI| MID |PRI| MP |PRI| TE |-TA
| |-- | PLR |---| |---| |---| |
-------- -------- -------- -------- --------
BKP| |
| -------- |
| | R6 | |
---------| BKP |-------
| MID |
--------
Figure 9.
Traffic Num of Labels Num of labels
before failure after failure
IP TRAFFIC (P-P) 1 2
Layer3 VPN (PE-PE) 2 3
Layer3 VPN (PE-P) 3 4
Layer2 VC (PE-PE) 2 3
Layer2 VC (PE-P) 3 4
Mid-point LSPs 1 2
7. Test Methodology
The procedure described in this section can be applied to all the 8
base test cases and the associated topologies. The backup as well as
the primary tunnels are configured to be alike in terms of bandwidth
usage. In order to benchmark failover with all possible label stack
depth applicable as seen with current deployments, it is RECOMMENDED
to perform all of the test cases provided in this section. The
forwarding performance test cases in section 7.1 MUST be performed
prior to performing the failover test cases.
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7.1. MPLS FRR Forwarding Performance
Benchmarking Failover Time [TERM-ID] for MPLS protection first
requires baseline measurement of the forwarding performance of the
test topology including the DUT. Forwarding performance is
benchmarked by the metric Throughput as defined in [Br91] and
measured in units pps. This section provides two test cases to
benchmark forwarding performance. These are with the DUT
configured as a Headend PLR, Mid-Point PLR, and Egress PLR.
7.1.1. Headend PLR Forwarding Performance
Objective
To benchmark the maximum rate (pps) on the PLR (as headend) over
primary LSP and backup LSP.
Test Setup
- Select any one topology out of the 8 from section 6.
- Select overlay technologies (e.g. IGP, VPN, or VC) with DUT
as Headend PLR.
- The DUT will also have 2 interfaces connected to the traffic
Generator/analyzer. (If the node downstream of the PLR is not
A simulated node, then the Ingress of the tunnel should have
one link connected to the traffic generator and the node
downstream to the PLR or the egress of the tunnel should have
a link connected to the traffic analyzer).
Procedure
1. Establish the primary LSP on R2 required by the topology
selected.
2. Establish the backup LSP on R2 required by the selected
topology.
3. Verify primary and backup LSPs are up and that primary is
protected.
4. Verify Fast Reroute protection is enabled and ready.
5. Setup traffic streams as described in section 5.7.
6. Send MPLS traffic over the primary LSP at the Throughput
supported by the DUT.
7. Record the Throughput over the primary LSP.
8. Trigger a link failure as described in section 5.1.
9. Verify that the offered load gets mapped to the backup tunnel
and measure the Additive Backup Delay.
10. 30 seconds after Failover, stop the offered load and
measure the Throughput, Packet Loss, Out-of-Order Packets,
and Duplicate Packets over the Backup LSP.
11. Adjust the offered load and repeat steps 6 through 10 until
the Throughput values for the primary and backup LSPs are
equal.
12. Record the Throughput. This is the offered load that will be
used for the Headend PLR failover test cases.
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7.1.2. Mid-Point PLR Forwarding Performance
Objective
To benchmark the maximum rate (pps) on the PLR (as mid-point) over
primary LSP and backup LSP.
Test Setup
- Select any one topology out of 8 from section 6.
- Select overlay technologies (e.g. IGP, VPN, or VC) with DUT
as Mid-Point PLR.
- The DUT will also have 2 interfaces connected to the traffic
generator.
Procedure
1. Establish the primary LSP on R1 required by the topology
selected.
2. Establish the backup LSP on R2 required by the selected
topology.
3. Verify primary and backup LSPs are up and that primary is
protected.
4. Verify Fast Reroute protection is enabled and ready.
5. Setup traffic streams as described in section 5.7.
6. Send MPLS traffic over the primary LSP at the Throughput
supported by the DUT.
7. Record the Throughput over the primary LSP.
8. Trigger a link failure as described in section 5.1.
9. Verify that the offered load gets mapped to the backup
tunnel and measure the Additive Backup Delay.
10. 30 seconds after Failover, stop the offered load and
measure the Throughput, Packet Loss, Out-of-Order Packets,
and Duplicate Packets over the Backup LSP.
11. Adjust the offered load and repeat steps 6 through 10 until
the Throughput values for the primary and backup LSPs are
equal.
12. Record the Throughput. This is the offered load that will
be used for the Mid-Point PLR failover test cases.
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7.1.3. Egress PLR Forwarding Performance
Objective
To benchmark the maximum rate (pps) on the PLR (as egress) over
primary LSP and backup LSP.
Test Setup
- Select any one topology out of 8 from section 6.
- Select overlay technologies (e.g. IGP, VPN, or VC) with DUT
as Egress PLR.
- The DUT will also have 2 interfaces connected to the traffic
generator.
Procedure
1. Establish the primary LSP on R1 required by the topology
selected.
2. Establish the backup LSP on R2 required by the selected
topology.
3. Verify primary and backup LSPs are up and that primary is
protected.
4. Verify Fast Reroute protection is enabled and ready.
5. Setup traffic streams as described in section 5.7.
6. Send MPLS traffic over the primary LSP at the Throughput
supported by the DUT.
7. Record the Throughput over the primary LSP.
8. Trigger a link failure as described in section 5.1.
9. Verify that the offered load gets mapped to the backup
tunnels and measure the Additive Backup Delay..
10. 30 seconds after Failover, stop the offered load and
measure the Throughput, Packet Loss, Out-of-Order Packets,
and Duplicate Packets over the Backup LSP.
11. Adjust the offered load and repeat steps 6 through 10 until
the Throughput values for the primary and backup LSPs are
equal.
12. Record the Throughput. This is the offered load that will be
used for the Egress PLR failover test cases.
7.2. Headend PLR with Link Failure
Objective
To benchmark the MPLS failover time due to link failure events
described in section 5.1 experienced by the DUT which is the
Headend PLR.
Test Setup
- Select any one topology out of 8 from section 6
- Select overlay technology for FRR test (e.g. IGP,VPN,or VC).
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- The DUT will also have 2 interfaces connected to the traffic
Generator/analyzer. (If the node downstream of the PLR is not
A simulated node, then the Ingress of the tunnel should have
one link connected to the traffic generator and the node
downstream to the PLR or the egress of the tunnel should have
a link connected to the traffic analyzer).
Test Configuration
1. Configure the number of primaries on R2 and the backups on R2
as required by the topology selected.
2. Configure the test setup to support Reversion.
3. Advertise prefixes (as per FRR Scalability Table described
in Appendix A) by the tail end.
Procedure
Test Case "7.1.1. Headend PLR Forwarding Performance" MUST be
completed first to obtain the Throughput to use as the offered
load.
1. Establish the primary LSP on R2 required by the topology
selected.
2. Establish the backup LSP on R2 required by the selected
topology.
3. Verify primary and backup LSPs are up and that primary is
protected.
4. Verify Fast Reroute protection is enabled and ready.
5. Setup traffic streams for the offered load as described
in section 5.7.
6. Provide the offered load from the tester at the Throughput
[Br91] level obtained from test case 7.1.1.
7. Verify traffic is switched over Primary LSP without packet
loss.
8. Trigger a link failure as described in section 5.1.
9. Verify that the offered load gets mapped to the backup
tunnel and measure the Additive Backup Delay.
10. 30 seconds after Failover [TERM-ID], stop the offered
load and measure the total Failover Packet Loss [TERM-ID].
11. Calculate the Failover Time [TERM-ID] benchmark using the
selected Failover Time Calculation Method (TBLM, PLBM, or
TBM) [TERM-ID].
12. Restart the offered load and restore the primary LSP to
verify Reversion [TERM-ID] occurs and measure the Reversion
Packet Loss [TERM-ID].
13. Calculate the Reversion Time [TERM-ID] benchmark using the
selected Failover Time Calculation Method (TBLM, PLBM, or
TBM) [TERM-ID].
14. Verify Headend signals new LSP and protection should be in
place again.
IT is RECOMMENDED that this procedure be repeated for each of
the link failure triggers defined in section 5.1.
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7.3. Mid-Point PLR with link failure
Objective
To benchmark the MPLS failover time due to link failure events
described in section 5.1 experienced by the DUT which
is the Mid-Point PLR.
Test Setup
- Select any one topology out of 8 from section 6
- Select overlay technology for FRR test as Mid-Point LSPs
- The DUT will also have 2 interfaces connected to the traffic
generator.
Test Configuration
1. Configure the number of primaries on R1 and the backups on R2
as required by the topology selected.
2. Configure the test setup to support Reversion.
3. Advertise prefixes (as per FRR Scalability Table described in
Appendix A) by the tail end.
Procedure
Test Case "7.1.2. Mid-Point PLR Forwarding Performance" MUST be
completed first to obtain the Throughput to use as the offered
load.
1. Establish the primary LSP on R1 required by the topology
selected.
2. Establish the backup LSP on R2 required by the selected
topology.
3. Perform steps 3 through 14 from section 7.2 Headend PLR
with Link Failure.
IT is RECOMMENDED that this procedure be repeated for each of
the link failure triggers defined in section 5.1.
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7.4. Headend PLR with Node Failure
Objective
To benchmark the MPLS failover time due to Node failure events
described in section 5.1 experienced by the DUT which is the
Headend PLR.
Test Setup
- Select any one topology from section 6.5 to 6.8
- Select overlay technology for FRR test (e.g. IGP, VPN, or VC)
- The DUT will also have 2 interfaces connected to the traffic
generator.
Test Configuration
1. Configure the number of primaries on R2 and the backups on R2
as required by the topology selected.
2. Configure the test setup to support Reversion.
3. Advertise prefixes (as per FRR Scalability table describe in
Appendix A) by the tail end.
Procedure
Test Case "7.1.1. Headend PLR Forwarding Performance" MUST be
completed first to obtain the Throughput to use as the offered
load.
1. Establish the primary LSP on R2 required by the topology
selected.
2. Establish the backup LSP on R2 required by the selected
topology.
3. Verify primary and backup LSPs are up and that primary is
protected.
4. Verify Fast Reroute protection.
5. Setup traffic streams for the offered load as described
in section 5.7.
6. Provide the offered load from the tester at the Throughput
[Br91] level obtained from test case 7.1.1.
7. Verify traffic is switched over Primary LSP without packet
loss.
8. Trigger a node failure as described in section 5.1.
9. Perform steps 9 through 14 in 7.2 Headend PLR with Link
Failure.
IT is RECOMMENDED that this procedure be repeated for each of
the node failure triggers defined in section 5.1.
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7.5. Mid-Point PLR with Node failure
Objective
To benchmark the MPLS failover time due to Node failure events
described in section 5.1 experienced by the DUT which is the
Mid-Point PLR.
Test Setup
- Select any one topology from section 6.5 to 6.8.
- Select overlay technology for FRR test as Mid-Point LSPs.
- The DUT will also have 2 interfaces connected to the traffic
generator.
Test Configuration
1. Configure the number of primaries on R1 and the backups on
R2 as required by the topology selected.
2. Configure the test setup to support Reversion.
3. Advertise prefixes (as per FRR Scalability table describe in
Appendix A) by the tail end.
Procedure
Test Case "7.1.2. Mid-Point PLR Forwarding Performance" MUST be
completed first to obtain the Throughput to use as the offered
load.
1. Establish the primary LSP on R1 required by the topology
selected.
2. Establish the backup LSP on R2 required by the selected
topology.
3. Verify primary and backup LSPs are up and that primary is
protected.
4. Verify Fast Reroute protection.
5. Setup traffic streams for the offered load as described
in section 5.7.
6. Provide the offered load from the tester at the Throughput
[Br91] level obtained from test case 7.1.1.
7. Verify traffic is switched over Primary LSP without packet
loss.
8. Trigger a node failure as described in section 5.1.
9. Perform steps 9 through 14 in 7.2 Headend PLR with Link
Failure.
IT is RECOMMENDED that this procedure be repeated for each of
the node failure triggers defined in section 5.1.
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8. Reporting Format
For each test, it is recommended that the results be reported in the
following format.
Parameter Units
IGP used for the test ISIS-TE/ OSPF-TE
Interface types Gige,POS,ATM,VLAN etc.
Packet Sizes offered to the DUT Bytes
Forwarding rate packets per second
IGP routes advertised Number of IGP routes
Penultimate Hop Popping Used/Not Used
RSVP hello timers Milliseconds
Number of FRR tunnels Number of tunnels
Number of VPN routes installed Number of VPN routes
on the Headend
Number of VC tunnels Number of VC tunnels
Number of BGP routes BGP routes installed
Number of mid-point tunnels Number of tunnels
Number of Prefixes protected by Number of LSPs
Primary
Topology being used Section number, and
figure reference
Failover Event Event type
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Benchmarks (to be recorded for each test case):
Failover-
Failover Time seconds
Failover Packet Loss packets
Additive Backup Delay seconds
Out-of-Order Packets packets
Duplicate Packets packets
Reversion-
Reversion Time seconds
Reversion Packet Loss packets
Additive Backup Delay seconds
Out-of-Order Packets packets
Duplicate Packets packets
Failover Time suggested above is calculated using one of the
following three methods
1. Packet-Based Loss method (PBLM): (Number of packets
dropped/packets per second * 1000) milliseconds. This method
could also be referred as Rate Derived method.
2. Time-Based Loss Method (TBLM): This method relies on the
ability of the Traffic generators to provide statistics which
reveal the duration of failure in milliseconds based on when
the packet loss occurred (interval between non-zero packet loss
and zero loss).
3. Timestamp Based Method (TBM): This method of failover
calculation is based on the timestamp that gets transmitted as
payload in the packets originated by the generator. The Traffic
Analyzer records the timestamp of the last packet received
before the failover event and the first packet after the
failover and derives the time based on the difference between
these 2 timestamps. Note: The payload could also contain
sequence numbers for out-of-order packet calculation and
duplicate packets.
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9. Security Considerations
Documents of this type do not directly affect the security of
Internet or corporate networks as long as benchmarking is not
performed on devices or systems connected to production networks.
Security threats and how to counter these in SIP and the media
layer is discussed in RFC3261, RFC3550, and RFC3711 and various
other drafts. This document attempts to formalize a set of
common methodology for benchmarking performance of failover
mechanisms in a lab environment.
10. IANA Considerations
This document requires no IANA considerations.
11. References
11.1. Informative References
NONE
11.2. Normative References
[TERM-ID] Poretsky S., Papneja R., Karthik J., Vapiwala S.,
"Benchmarking Terminology for Protection Performance",
draft-ietf-bmwg-protection-term-06.txt, work in
progress.
[MPLS-FRR-EXT] Pan P., Swallow G., Atlas A., "Fast Reroute
Extensions to RSVP-TE for LSP Tunnels", RFC 4090.
[IGP-METH] S. Poretsky, B. Imhoff, "Benchmarking Methodology
for IGP Data Plane Route Convergence, "draft-ietf-
bmwg-igp-dataplane-conv-meth-17.txt", work in progress.
[Br91] Bradner, S., Editor, "Benchmarking Terminology for
Network Interconnection Devices", RFC 1242, July 1991.
[Br97] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", RFC 2119, July 1997.
[Ma98] Mandeville, R., "Benchmarking Terminology for LAN
Switching Devices", RFC 2285, February 1998.
[Po06] Poretsky, S., et al., "Terminology for Benchmarking
Network-layer Traffic Control Mechanisms", RFC 4689,
November 2006.
12. Acknowledgments
We would like to thank Jean Philip Vasseur for his invaluable input
to the document and Curtis Villamizar his contribution in suggesting
text on definition and need for benchmarking Correlated failures.
Additionally we would like to thank Al Morton, Arun Gandhi,
Amrit Hanspal, Karu Ratnam, Raveesh Janardan, Andrey Kiselev, and
Mohan Nanduri for their formal reviews of this document.
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Author's Addresses
Rajiv Papneja
Isocore
12359 Sunrise Valley Drive, STE 100
Reston, VA 20190
USA
Phone: +1 703 860 9273
Email: rpapneja@isocore.com
Samir Vapiwala
Cisco System
300 Beaver Brook Road
Boxborough, MA 01719
USA
Phone: +1 978 936 1484
Email: svapiwal@cisco.com
Jay Karthik
Cisco System
300 Beaver Brook Road
Boxborough, MA 01719
USA
Phone: +1 978 936 0533
Email: jkarthik@cisco.com
Scott Poretsky
Allot Communications
USA
Phone: +1 508 309 2179
EMail: sporetsky@allot.com
Shankar Rao
Qwest Communications,
950 17th Street
Suite 1900
Qwest Communications
Denver, CO 80210
USA
Phone: + 1 303 437 6643
Email: shankar.rao@qwest.com
Jean-Louis Le Roux
France Telecom
2 av Pierre Marzin
22300 Lannion
France
Phone: 00 33 2 96 05 30 20
Email: jeanlouis.leroux@orange-ft.com
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Appendix A: Fast Reroute Scalability Table
This section provides the recommended numbers for evaluating the
scalability of fast reroute implementations. It also recommends the
typical numbers for IGP/VPNv4 Prefixes, LSP Tunnels and VC entries.
Based on the features supported by the device under test (DUT),
appropriate scaling limits can be used for the test bed.
A1. FRR IGP Table
No. of Headend TE Tunnels IGP Prefixes
1 100
1 500
1 1000
1 2000
1 5000
2 (Load Balance) 100
2 (Load Balance) 500
2 (Load Balance) 1000
2 (Load Balance) 2000
2 (Load Balance) 5000
100 100
500 500
1000 1000
2000 2000
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A 2. FRR VPN Table
No. of Headend TE Tunnels VPNv4 Prefixes
1 100
1 500
1 1000
1 2000
1 5000
1 10000
1 20000
1 Max
2 (Load Balance) 100
2 (Load Balance) 500
2 (Load Balance) 1000
2 (Load Balance) 2000
2 (Load Balance) 5000
2 (Load Balance) 10000
2 (Load Balance) 20000
2 (Load Balance) Max
A 3. FRR Mid-Point LSP Table
No of Mid-point TE LSPs could be configured at recommended levels -
100, 500, 1000, 2000, or max supported number.
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A 4. FRR VC Table
No. of Headend TE Tunnels VC entries
1 100
1 500
1 1000
1 2000
1 Max
100 100
500 500
1000 1000
2000 2000
Appendix B: Abbreviations
BFD - Bidirectional Fault Detection
BGP - Border Gateway protocol
CE - Customer Edge
DUT - Device Under Test
FRR - Fast Reroute
IGP - Interior Gateway Protocol
IP - Internet Protocol
LSP - Label Switched Path
MP - Merge Point
MPLS - Multi Protocol Label Switching
N-Nhop - Next - Next Hop
Nhop - Next Hop
OIR - Online Insertion and Removal
P - Provider
PE - Provider Edge
PHP - Penultimate Hop Popping
PLR - Point of Local Repair
RSVP - Resource reSerVation Protocol
SRLG - Shared Risk Link Group
TA - Traffic Analyzer
TE - Traffic Engineering
TG - Traffic Generator
VC - Virtual Circuit
VPN - Virtual Private Network
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