IGP Data Plane Convergence Benchmarking draft-ietf-bmwg-igp-dataplane-conv-app-00.txt draft-ietf-bmwg-igp-dataplane-conv-term-00.txt draft -ietf-bmwg-igp-dataplane-conv-meth-00.txt

1
IGP Data Plane Convergence Benchmarking
draft-ietf-bmwg-igp-dataplane-conv-app-00.txt
draft-ietf-bmwg-igp-dataplane-conv-term-00.txt
draft -ietf-bmwg-igp-dataplane-conv-meth-00.txt

• Authors
• Scott Poretsky Avici Systems
• Brent Imhoff WilTel Communications

57th IETF Meeting Vienna
2
Motivation for Draft

• IGP Convergence has become the most heavily
  discussed Router Benchmark for the Internet
• Convergence events cause packet loss visible to
  the network user for most real-time applications
• Industry Goal lt1sec (milliseconds) IGP
  Convergence
• As stated at numerous NANOGs by Service
  Providers and router vendors.
• Applies to IS-IS and OSPF.
• Externally observable Black-Box event.

3
Convergence Methodologies

• Control Plane Convergence
• Data Plane Convergence

• The point in time in which a single node
  advertises the route table change to its peer in
  a route advertisement message
• Control Plane Convergence is in order of hundreds
  of milliseconds
• Addressed in draft-ietf-bmwg-ospfconv-terminology
  and methodology

• The point in time in which a single node updates
  its routing table and reroutes traffic to the new
  next-hop
• Data Plane Convergence is in the order of seconds
• Data Plane Convergence is the major problem to
  solve
• Addressed in draft-ietf-bmwg-igp-dataplane-conv-te
  rm meth and app

4
Basic Test Methodology

• Test Procedure
• Send maximum Throughput with fixed packet size to
  all destinations in the FIB
• Measure pps received at Tester
• Force a Network Event
• Observe loss of traffic forwarding
• Observe recovery to forwarding at line rate
• Calculate Convergence Time

Test Setup
DUT
Link 1
Link 2
Tester

• Test Configuration
• Tester_1 advertises simulated topology via
  routing protocol(s)
• Tester_2 sends traffic to DUT to all destinations
  in FIB
• DUT has two paths (via Link 1 and Link 2) to
  reach destinations
• DUT by default prefers lower cost path via Link 1
• Network Event reroutes traffic to Link 2

NOTE Different test cases Described in draft.
5
Example Convergence Measurement
Packet Sampling Interval
Rate-Derived Convergence Time
Convergence Start Time
Convergence End Time
Route Convergence Recovery Transition
Route Convergence Event Transition
Packet Loss
Convergence Time
6
Data Plane Convergence Calculation

• Calculation 1
• Rate-Derived Convergence Time Time to converge
  100 of the traffic to all routes in FIB after a
  Convergence Event
• Calculation 2
• Loss-Derived Convergence Time (Number of
  Packets Lost)/(Offered Packet Load per Second)
• Applying Calculations
• Loss-Derived Convergence Time gt Rate-Derived
  Convergence Time
• Rate-Derived Convergence Time is Preferred
• Loss-Derived Convergence Time must be used when
  Packet Sampling Interval gt100msec.

7
Next Steps Terminology Draft 01

• Add global statement that metrics are externally
  observable
• Add new terms Packet Sampling Interval
  Convergence Start Time Convergence End Time (as
  shown in5)
• Change terms to match those suggested on mailing
  list (and used ins 5 and 6)
• Full Convergence Time -gt Rate-Derived Convergence
  Time
• Average Convergence Time -gt Loss-Derived
  Convergence Time
• Route Convergence Event Slope -gt Route
  Convergence Event Transition
• Route Convergence Recovery Slope -gt Route
  Convergence RecoveryTransition
• Reroute Convergence Time -gt Route Convergence
  Time
• (Definitions are not changing only terms)
• the ready for Last Call for IESG Review

8
Next Steps Methodology Draft 01

• Add Reporting Format with Packet Sampling
  Interval IGP Timer values fixed packet size
  and FIB size used and results for Rate-Derived
  Convergence Time and Loss-Derived Convergence
  Time.
• Add suggested values for IGP Timers to Test
  Considerations section
• Add Guidelines for Packet Sampling Interval to
  Test Considerations section as discussed in
  6
• then ready for Last Call for IESG Review