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  1. 1. IPTV / IPMulticast End-to-End Greg Shepherd (shep@cisco.com)
  2. 2. Agenda <ul><li>IPTV Deployments </li></ul><ul><li>Impact of Packet Loss on MPEG2 Frames </li></ul><ul><li>Network Impairment Contributors </li></ul><ul><li>CRS IPMulticast Test Data </li></ul><ul><li>Summary </li></ul><ul><li>Future Challenges </li></ul>
  3. 3. IPTV Deployments today <ul><li>Two schools of thought in deployments today: </li></ul><ul><ul><li>I think I need 50ms cvg </li></ul></ul><ul><ul><li>IPMulticast is fast enough </li></ul></ul><ul><li>IPMulticast is UDP </li></ul><ul><ul><li>The only acceptable loss is 0ms </li></ul></ul><ul><ul><li>How much is “reasonable”? </li></ul></ul><ul><li>50ms “requirement” is not a video requirement </li></ul><ul><ul><li>Legacy telco voice requirement </li></ul></ul><ul><ul><li>Efforts for 50ms only cover a limited portion network events </li></ul></ul><ul><li>Where to put the effort? </li></ul><ul><ul><li>Make IPMulticast better? </li></ul></ul><ul><ul><li>Improve the transport? </li></ul></ul><ul><ul><li>Add layers of network complexity to improve core convergence? </li></ul></ul>
  4. 4. Agenda <ul><li>IPTV Deployments </li></ul><ul><li>Impact of Packet Loss on MPEG2 Frames </li></ul><ul><li>Network Impairment Contributors </li></ul><ul><li>CRS IPMulticast Convergence Test Data </li></ul><ul><li>Summary </li></ul><ul><li>Future Challenges </li></ul>
  5. 5. Impact of Packet Loss on MPEG Stream 0% Packet Loss 0.5 % Packet Loss 5 % Packet Loss Video is very susceptible to IP Impairments
  6. 6. Impact of Packet Loss on MPEG Stream <ul><li>Compressed Digitized Video is sent as I, B, P Frames </li></ul><ul><li>I-frames: contain full picture information </li></ul><ul><ul><li>Transmit I frames approximately every 15 frames (GOP interval) </li></ul></ul><ul><li>P-frames: predicted from past I or P frames </li></ul><ul><li>B-frames: use past and future I or P frames </li></ul>I-frame loss “corrupts” P/B frames for the entire GOP
  7. 7. Impact of Packet Loss on MPEG Stream <ul><li>Example Assumptions: </li></ul><ul><ul><li>MPEG2 stream CBR = 4.8828Mbps </li></ul></ul><ul><ul><li>MPEG2 IP stream pps = 427.35pps </li></ul></ul><ul><ul><li>L3 pkt_size = 1487Bytes (encap IP + UDP + RTP) </li></ul></ul><ul><ul><li>GOP-size-in-msec 480 </li></ul></ul><ul><ul><li>GOP-size-in-pkts 205 </li></ul></ul>Network events create correlated packet loss, not random single packet loss. What’s the relationship between network CVG time and I-frame loss?
  8. 8. MPEG Frame Impact from Packet Loss 32%
  9. 9. MPEG Frame Impact from Packet Loss <ul><li>P/B frame loss is less noticeable </li></ul><ul><ul><li>Error concealment techniques in the receiver can mask some </li></ul></ul><ul><li>I-Frames loss is more problematic </li></ul><ul><ul><li>I-frame loss can result in an entire GOP loss </li></ul></ul><ul><ul><li>A single packet lost from an I-frame corrupts the entire I-frame </li></ul></ul><ul><ul><li>I-frame (GOP) loss can result in blank screen for 1-2 secs </li></ul></ul><ul><li>50ms is a phantom goal </li></ul><ul><ul><li>32% chance of I-frame loss </li></ul></ul><ul><ul><li>..another way.. </li></ul></ul><ul><ul><li>32% of your streams will have 1-2 sec blank screen outage </li></ul></ul><ul><ul><li>Why then is this a goal for some? </li></ul></ul>
  10. 10. Agenda <ul><li>IPTV Deployments </li></ul><ul><li>Impact of Packet Loss on MPEG2 Frames </li></ul><ul><li>Network Impairment Contributors </li></ul><ul><li>CRS IPMulticast Convergence Test Data </li></ul><ul><li>Summary </li></ul><ul><li>Future Challenges </li></ul>
  11. 11. What are the Impairment Contributors? <ul><li>Link Failures </li></ul><ul><li>Node Failures </li></ul><ul><li>Random Uncorrected Bit Errors </li></ul><ul><li>Congestion </li></ul><ul><li>How do we measure these? </li></ul>
  12. 12. What are the Impairment Contributors? <ul><li>1st: Need Quantify Impairments </li></ul><ul><ul><li>Need some “standard” </li></ul></ul><ul><ul><li>Relevant to viewers’ experience </li></ul></ul><ul><li># Impairments per 2 hours </li></ul><ul><ul><li>Representative of a typical movie duration </li></ul></ul><ul><ul><li>Allow for comparing contributions over a standard window of time </li></ul></ul>
  13. 13. What are the Impairment Contributors? <ul><li>Some Assumptions / Some Industry Standard Data / Some Customer Experience Data </li></ul><ul><li>Total Value Across a Typical Provider Network </li></ul><ul><li>Trunk Failures - .0010 Imp/2hr </li></ul><ul><li>HW Card Failures - .0003 Imp/2hr </li></ul><ul><li>SW Failures - .0012 Imp/2hr </li></ul><ul><ul><li>NSF/SSO reduces the realized amount of this contribution </li></ul></ul><ul><li>SW Upgrades - .0037 Imp/2hr </li></ul><ul><ul><li>Modular code (IOS-XR) reduces the realized amount of this contribution </li></ul></ul>
  14. 14. What are the Impairment Contributors? <ul><li>Uncorrected Bit Errors - 11.4629 Imp/2hrs </li></ul><ul><ul><li>&quot;Video over IP&quot; by WesSimpson (page 238) - 10 -10 per trunk </li></ul></ul>Trunk Failures: .0010 HW Failures: .0003 SW Failures: .0012 Maintenance: .0037 Total: .0062 Imp/2hrs
  15. 15. Network Impairment Contributors <ul><li>All HW/SW/Link failures combined do not compare to uncorrected bit errors </li></ul><ul><li>Last-mile networks often most significant contributors </li></ul><ul><li>SW failures/Maintenance each contribute much more than link failures </li></ul><ul><ul><li>Stable, modular software with NSF/SSO can reduce this contribution even further </li></ul></ul><ul><li>Fast convergence in the core is a worthy goal </li></ul><ul><ul><li>Improves core-contributed artifacts </li></ul></ul><ul><ul><li>Need to consider the balance of a solid platform vs. layered complexity </li></ul></ul><ul><li>Solid performing platform is more important than complex protocol solutions </li></ul>
  16. 16. Agenda <ul><li>IPTV Deployments </li></ul><ul><li>Impact of Packet Loss on MPEG2 Frames </li></ul><ul><li>Network Impairment Contributors </li></ul><ul><li>CRS IPMulticast Convergence Test Data </li></ul><ul><li>Summary </li></ul><ul><li>Future Challenges </li></ul>
  17. 17. Internal CRS Multicast Convergence Test <ul><li>Typical customer topologies </li></ul><ul><ul><li>Most tree repairs are single-hop repairs </li></ul></ul><ul><li>Typical customer network configurations </li></ul><ul><ul><li>2500 IGP routes </li></ul></ul><ul><ul><li>250k BGP routes </li></ul></ul><ul><ul><li>Tests of 400 - 4000 (S,G) SSM entries </li></ul></ul><ul><li>ISIS Prefix Prioritization </li></ul><ul><ul><li>Loopbacks </li></ul></ul><ul><ul><li>Multicast source prefixes </li></ul></ul><ul><ul><li>Not yet in OSPF </li></ul></ul>
  18. 18. Summary across all available CRS1 data <ul><li>And most important… CRS1 SSM Convergence is rather quick! </li></ul>4000 IPTV channels 800 IPTV channels 400 IPTV channels 2500 IGP, 250k BGP
  19. 19. Summary across all available CRS1 data <ul><li>UC has negligible impact on MC behavior whether 2500 or 5000 ISIS prefixes </li></ul>
  20. 20. MPEG Frame Impact from Packet Loss Competitor systems can take 1sec or MORE to converge 400 (S,G) entries 100%
  21. 21. IPMcast QOS Requirements <ul><li>Network congestion is not a significant impairment contributor </li></ul><ul><ul><li>..normally.. </li></ul></ul><ul><li>BUT it is a necessary safety-net </li></ul><ul><li>On-network multicast traffic is well known </li></ul><ul><ul><li>Flows, rates, sources.. </li></ul></ul><ul><li>Access can sycronize/spike </li></ul><ul><ul><li>“ Mother’s day” events </li></ul></ul><ul><li>Real-time (VoIP) traffic should not suffer from other traffic events </li></ul>
  22. 22. Triple-Play QOS test assumptions <ul><li>Support 4 classes of service with a strict priority relationship between these classes as follows: </li></ul><ul><ul><li>Unicast High > Multicast High > Multicast Low > Unicast Low </li></ul></ul><ul><ul><li>ie: Voip > Premium Vid > Broadcast Vid > Access </li></ul></ul><ul><li>Full line rate performance is expected for all traffic transmitted in each class when uncongested. </li></ul><ul><li>No effects observed on higher class performance due to traffic transmission on a lower class. </li></ul><ul><li>No effect on unicast traffic, nor should the unicast traffic effect the multicast traffic. </li></ul><ul><li>Congested interface should not affect same multicast flow(s) destined to adjacent uncongested interfaces. </li></ul>
  23. 23. QOS Test Configuration 2 SPIRENT AX-4000 - Port 2 HPM,LPM LPU HPU + HPM + LPM + LPU = 100% HPU + HPM + LPM + LPU > 100% TenGigE0/0/0/3 TenGigE0/0/0/1 TenGigE0/0/0/0 SPIRENT AX-4000 Port 3 Port 1 CRS-1 TenGigE0/0/0/4 Port 4 TenGigE0/0/0/5 Port 5 TenGigE0/0/0/6 Port 6 HPU Strict Priority order for dropping HPU > HPM > LPM > LPU
  24. 24. QOS Test 2 - 1of3
  25. 25. QOS Test 2 - 2of3
  26. 26. QOS Test 2 - 3of3
  27. 27. QOS Test 2 - Port 4 QOS profile is maintained on the adjacent interface with zero packet loss of the higher priority traffic.
  28. 28. QOS Test Configuration 3 SPIRENT AX-4000 - Port 2 HPU, LPM LPU HPU + HPM + LPM + LPU = 100% HPU + HPM + LPM + LPU > 100% TenGigE0/0/0/2 TenGigE0/0/0/1 TenGigE0/0/0/0 SPIRENT AX-4000 Port 3 Port 1 CRS-1 HPU = 55%, LPM = 30%, LPU= 5% HPM step from 10% to 90% HPM
  29. 29. QOS Test Configuration 3 SPIRENT AX-4000 - Port 2 HPU, LPM LPU HPU + HPM + LPM + LPU = 100% HPU + HPM + LPM + LPU > 100% TenGigE0/0/0/2 TenGigE0/0/0/1 TenGigE0/0/0/0 SPIRENT AX-4000 Port 3 Port 1 CRS-1 Test parameters: Rate: Data traffic for HPU,LPM and LPU is fixed at 5.5Gb/s, 3.0Gb/s and 0.5Gb/s respectively. HPM traffic follows square wave pattern from 1.0Gb/s for 30secs to 9Gb/s for 20secs to represent bursty HPM traffic Packet size: 220 bytes for HPU, 1496 for HPM, LPM and LPU HPM
  30. 30. QOS Test 3
  31. 31. CRS IPMulticast Test Summary <ul><li>CRS is the IPTV / IPMcast Industry Leader </li></ul><ul><li>IPMcast convergence is exceptionally fast </li></ul><ul><ul><li>And improving through constant engineering efforts </li></ul></ul><ul><ul><li>No need to chase phantom numbers </li></ul></ul><ul><li>QOS performance is unmatched </li></ul>
  32. 32. Agenda <ul><li>IPTV Deployments </li></ul><ul><li>Impact of Packet Loss on MPEG2 Frames </li></ul><ul><li>Network Impairment Contributors </li></ul><ul><li>CRS IPMulticast Test Data </li></ul><ul><li>Summary </li></ul><ul><li>Future Challenges </li></ul>
  33. 33. IPTV Deployments today <ul><li>Native IPMulticast performance in the CRS is a driving factor </li></ul><ul><ul><li>Mcast PPS </li></ul></ul><ul><ul><li>Fan-out </li></ul></ul><ul><ul><li>IPMcast convergence </li></ul></ul><ul><ul><li>Unicast/Mcast QOS </li></ul></ul><ul><li>200 - 1000 (S,G)s is typical </li></ul><ul><li>Cable, DSL, and Satellite </li></ul><ul><li>The largest is testing 10,000 (S,G)s as its goal </li></ul><ul><ul><li>Has chosen native IPMcast over PtMP </li></ul></ul><ul><ul><li>High performance of the CRS (exceeded requirements) </li></ul></ul><ul><ul><li>Simple to configure, maintain, operate, etc.. </li></ul></ul>
  34. 34. IPTV Deployments Today <ul><li>Beginning to see the 50ms “requirement” disbanded </li></ul><ul><ul><li>Scalability and stability of CRS/XR </li></ul></ul><ul><ul><li>Simplicity of IPMcast </li></ul></ul><ul><li>Overlay solutions do not reduce frequency of impairments </li></ul><ul><ul><li>Never reaches 0 loss (never really reaches the 50ms goal) </li></ul></ul><ul><ul><li>May doesn’t address link-up transitions </li></ul></ul><ul><ul><li>Adds excessive network and operational complexity for little gain </li></ul></ul><ul><li>Selecting the right platform is the best solution </li></ul>
  35. 35. Agenda <ul><li>IPTV Deployments </li></ul><ul><li>Impact of Packet Loss on MPEG2 Frames </li></ul><ul><li>Network Impairment Contributors </li></ul><ul><li>CRS IPMulticast Test Data </li></ul><ul><li>Summary </li></ul><ul><li>Future Challenges </li></ul>
  36. 36. Future Challenges <ul><li>Current IPTV is a value added service </li></ul><ul><ul><li>On-net injection </li></ul></ul><ul><ul><li>PPV or local Advertising Revenue </li></ul></ul><ul><li>Walled Garden </li></ul><ul><ul><li>Edge provider “owns” the customer </li></ul></ul><ul><li>Will this last? </li></ul>
  37. 37. Future Challenges <ul><li>Access bandwidth is driven by competition </li></ul><ul><li>Access bandwidth rapidly surpassing video bandwidth </li></ul><ul><li>Video bandwidth is semi-bounded </li></ul>
  38. 38. Future Challenges <ul><li>IPTV works as a Value Added service today </li></ul><ul><li>Access bandwidth growth opens up new applications </li></ul><ul><li>Over-the-top video is already here - in some form.. </li></ul><ul><ul><li>Joost, MacTV, YouTube, BitTorrent, AMT </li></ul></ul><ul><li>More available bandwidth will only improve these applications </li></ul><ul><li>DVRs are changing how people watch TV </li></ul><ul><li>Consumers don’t care how their DVRs are populated </li></ul><ul><li>Will live-TV be relevant in the future? </li></ul>
  39. 39. Future Challenges <ul><li>How does a provider say in the food-chain? </li></ul><ul><li>Continue to expand content offering </li></ul><ul><ul><li>Stay ahead of the curve </li></ul></ul><ul><li>Open IPMcast transport to off-net content </li></ul><ul><ul><li>Look for key strategic content partners </li></ul></ul><ul><li>Integrated Directory API </li></ul><ul><ul><li>Cisco/SciAtl </li></ul></ul>
  40. 40. Thank You

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