Performance Evaluation of EF-Admit draft-gunn-tsvwg-ef-admit-evaluation-00 with updates

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Performance Evaluation of EF-Admitdraft-gunn-tsv
wg-ef-admit-evaluation-00with updates

• J. Gunn
• Computer Sciences Corporation
• R. Lichtenfels
• National Communications System
• D. Garbin
• D. Masi
• Noblis
• P. McGregor
• Nyquetek

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Outline

• Background / Motivation
• EF-ADMIT
• Scenarios/Assumptions
• (updates since -00)
• Results
• (updates since -00)
• Conclusions
• Next Steps

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Background / Motivation

• EF-ADMIT proposed as a new DSCP to distinguish
  real time traffic subject to strict CAC from real
  time traffic subject to weak or no CAC
• Interested in protecting ETS calls (as described
  in IEPREP) under severe congestion
• Sustained high traffic
• Extensive network failure
• ETS calls can be subject to CAC (and thus can use
  EF-ADMIT) even when economic concerns mean that
  many normal calls are subject to weaker (or no)
  CAC.
• How well can EF-ADMIT protect the ETS strict
  CAC calls when network is overloaded?

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2 EF - 2 Queue Model
Policer 1
EF-ADMIT Strict CAC Voice
Priority Queue
Policer 2
EF Voice
Line Transmission 256 Kb, 1.5 Mb, 45 Mb
Baseline
AF1 Video
CBWFQ
AF2 Data
BE Data
EF Expedited Forwarding (e.g., VoIP) AF1
Assured Forwarding (Video) AF2 Assured
Forwarding (signaling) BE Best Effort (Other
Data) CBWFQ Class Based Weighted Fair Queuing
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2 EF - 1 Queue Model
Policer 1
EF-ADMIT Strict CAC Voice
Priority Queue
Policer 2
EF Voice
Line Transmission 256 Kb, 1.5 Mb, 45 Mb
Baseline
AF1 Video
CBWFQ
AF2 Data
BE Data
EF Expedited Forwarding (e.g., VoIP) AF1
Assured Forwarding (Video) AF2 Assured
Forwarding (signaling) BE Best Effort (Other
Data) CBWFQ Class Based Weighted Fair Queuing
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Scenarios/Assumptions (-01 version)

• Access line speeds- 256 Kb, 1.5 Mb, 45 Mb
• EF-ADMIT traffic is small compared to EF traffic
  (10 of base EF)
• Baseline traffic mix includes EF/EF-ADMIT
  (Voice), AF1 (Video), AF2 (Data) and BE (Data)
• Network Control traffic modeled as AF2- and is
  protected by EF policing
• Baseline (overall) approx 80 utilization for 256
  Kb, 1.5 Mb
• Baseline (overall) approx 55 utilization for
  45Mbps
• 10X Overload applies to all except the EF-ADMIT
  and AF2 traffic
• Policing
• Regular EF policed to approx 50 of line speed,
• No policing on AF and BE
• Primary Scenarios (for each speed)
• 1EF, 1Q (current operation)
• 2EF, 1Q
• 2EF, 2Q
• Secondary Scenarios- only for higher speeds
• Mix Voice and Video in the EF-ADMIT stream

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256 Kbps Results

• Delay and jitter for EF not relevant because only
  10 of the packets for each call get through
• For EF-ADMIT, delay is better for 2Q (14 ms vs.
  23 ms), jitter is about the same (50 ms)
• Drop rate almost identical for 1Q and 2Q

10 calls
1 call
10 calls, each getting 10
1 call, getting 100
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1.5 Mbps Results

• Delay and jitter for EF not relevant because only
  15 of the packets for each call get through
• For EF-ADMIT, delay and jitter are both below 10
  ms, for both 1Q and 2Q
• Introducing EF-ADMIT video worsens delay and
  jitter for both EF and EF ADMIT- slightly worse
  for EF-ADMIT with1Q (5ms delay, 16 ms jitter)
• Drop rate almost identical for 1Q and 2Q

EF - 50 calls
EF- ADMIT -1 call
50 calls, each getting small
1 call, getting 100
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45 Mbps Results

• Delay and jitter for EF not relevant because only
  small of the packets for each call get through
• For EF-ADMIT, delay and jitter are both below 1
  ms, for both 1Q and 2Q
• Introducing EF-ADMIT video has little effect on
  delay and jitter for both EF and EF ADMIT
• Drop rate almost identical for 1Q and 2Q

1000 calls, each getting small
10 call, each getting 100
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Conclusions

• Simulation and analytical results confirm the
  expectations described in draft-ietf-tsvwg-admitte
  d-realtime-dscp-00
• When EF traffic is properly policed, the EF-ADMIT
  traffic is protected from the effects (dropping,
  delay, jitter) of a major overload of EF (and
  AF, etc.) traffic
• When EF traffic is properly policed, the 1Q and
  2Q cases perform very similarly if all the and
  EF and EF-ADMIT is Voice (short packets)
• When video (long packets) traffic is introduced
  to the EF-ADMIT traffic, delay and jitter suffer
  at 1.5 Mbps- little impact at 45 Mbps
• These results demonstrate significant value in
  preserving EF-ADMIT performance even when
  overload significant causes degradation of EF
  performance.
• In the context of essential network services for
  disaster response (as addressed in IEPREP), we
  conclude that EF-ADMIT can help ensure that
  disaster response service is assured under all
  circumstances.

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Next Steps

• Model other arrival rate and packet size
  distributions, for sensitivity
• Evaluate the implications of mixing voice
  signaling traffic with voice bearer traffic in
  the same PHBs.
• Address how to best to ensure video capabilities
  for disaster recovery under all circumstances.
• Address disaster recovery data services,
  particularly in terms of how well the needs can
  be met by appropriate assignments within the
  framework of the existing AF classes.
• Corroborate the event simulation and analysis
  results with a prototype implementation of the
  model configuration in the laboratory and testing
  the performance for the various scenarios.
• Investigate sensitivity to variations in policing
• Thank you for comments which contributed to -01
  and Next Steps
• Fred Baker
• Ken Carlberg