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Bandwidth Playbook

Bandwidth Playbook. Thwarting Fiber-to-the-Home Competition. John J. Downey Broadband Network Engineer Cisco Systems jdowney@cisco.com. Agenda. Speeds and Feeds Competitive Outlook (FiOS) Objectives Current & New Speed Offerings Future Evolution Options Cablevision’s Choice Configs

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Bandwidth Playbook

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  1. Bandwidth Playbook Thwarting Fiber-to-the-Home Competition John J. Downey Broadband Network Engineer Cisco Systems jdowney@cisco.com

  2. Agenda • Speeds and Feeds • Competitive Outlook (FiOS) • Objectives • Current & New Speed Offerings • Future Evolution Options • Cablevision’s Choice • Configs • Cabling Ideas • Other Ideas • New Technology Cornerstones

  3. Speeds and Feeds

  4. Objectives • Use existing HFC network • Separation of tiers of service • Bandwidth usage monitoring/shaping • Security Issues - mitigate “hackers” • Number of subs per port

  5. Current and New Speed Offerings • Typically 1 tier at 3M DS by 384K US • MSOs using 1.1 to migrate to multiple tiers of service • Dial-up replacement 128K x 128K • Low to Med speed 1M x 256K or 3M x 384K • High speed 5-7M x 512-768K • Offerings from Verizon • 10x2 Mbps, 20x5, & 30x5 FTTH • New residential & commercial offerings • 15x2 - Cox • 10x1, 15x2, 30x5 - CV • 16x2 - Comcast • 20x? - RCN

  6. Usage Patterns • Changing “cap” at same price may not have linear affect • Average usage may be less than extrapolated • Customers that use a lot of P2P services may look more appealing to others outside network • Offering 15 Mbps at 100:1 oversell allows 200 subs/DS & may be fine, but needs to be observed over time • Customers paying for higher “cap” could feel compelled to get their moneys worth and use much more than previous • Usage could increase exponentially • Customers become more computer savvy • Other applications become prolific or just temporary • Equates to an over-subscription calculation that must be re-evaluated and probably decreased

  7. DS Speed Affected by: • Usable rate and frame size • Modem • Config file, CPU (PPS), & Ethernet • Transport layer • TCP or UDP • US speeds & windowing affect TCP • Max DS burst - perception is reality • VoIP jitter? • Computer OS and Windows stack

  8. US Speed Affected by: • Rate limit & other traffic DOCSIS Protocol • Map advance, DS interleaving & Modulation • Concatenation • Max concat & traffic burst settings • Modulation profiles • Fragmentation • DOCSIS 1.0 CM?

  9. Future Evolution Options

  10. Solutions • Do nothing and watch the competition erode your subscriber base • Segment the fiber nodes • FTTC, FTTH(P), FTTWAP • “Bonding” US & DS DOCSIS channels

  11. Option 1 - Same CMTS with Frequency Separation

  12. Option 1 - Same CMTS with Freq Separation • Map 2 DS freqs & 2 US Rxs into same node • Freq A serving Res subs & freq B serving new subs • Utilize 256-QAM on both DSs • 36 Mbps per DS freq (depends on frame size) • Utilize 3.2 MHz CW/16-QAM on both USs • 9 Mbps per US freq (depends on frame size) • US and/or DS load balance • Allow res subs to use under-utilized commercial US • Client-class processing "steers" Res subs to A & new subs to B • Set DS freq and/or US Ch ID in CM’s config file

  13. Scope Scope Client Entries Client Classes Client Classes Scopes Scopes Tags Tags PC X MAC Address: ab:cd:ef:01:02:03 Scope Scope Modem Tag Modem Tag INET Modem Class Res Modem Class 01:02:03:04:05:06 10.2.2.0 10.1.1.0 .2-.124 .2-.124 Modem Tag Modem Tag 01:02:03:04:05:06 scope ... PC Tag PC Class 24.1.1.0 .. .125-.255 PC tag .. . Cable Modem X Cable Modem Y 02:03:04:06:aa:06 MAC Address: MAC Address: 02:03:04:06:aa:06 ab:cd:ef:01:02:03 Separating CMs Through Client-Class Processing CMTS Provisioning Server

  14. DS0 U0 U1 U2 U3 DS1 U0 U1 U2 U3 Option 1 - Separating CMs via FDM & Provisioning DS0 = 453 MHz @ 256-QAM DS1 = 459 MHz @ 256-QAM U0 = 20.0 MHz @ 3.2 MHz U0 = 23.2 MHz @ 3.2 MHz

  15. Option 1 - Questions to Answer • Multiple DSs broadcast because of EDFAs? • Broadcast makes it difficult to achieve 1:1 DS-to-node combining later down the road • Nodes with 1 DS Rx & 2 US Txs? • Two DSs could be sent to node • 1 US laser feeds US of 1 mac domain • 2nd laser feeds US from other mac domain • US frequency re-use possible

  16. Option 1 – Pros and Cons

  17. Option 1 - Pros • Provides simple "get up and run" approach • Only real modifications are: • Combining to map 2-4 USs to nodes • Ensure provisioning system steers them to proper US ch • US and DS load balancing possible • “Poor man’s” redundancy • Caution across cards - packet drops because no IM alignment between cards • If using mixed mode, then 2.0 CMs could burst at 64-QAM for ~ 13 Mbps

  18. Option 1 - Pros (cont) • 2 DSs at 256-QAM = ~ 72 Mbps • 2 USs at 16-QAM / 3.2 MHz = ~ 18 Mbps • Advanced phy features • Ingress cancellation and more FEC • 24-tap EQ & US interleave • A/D conversion • 5x20U has advanced spectrum management, remote analyzing and per-CM FEC counters • Available with 12.3(13) IOS & >

  19. Option 1 - Cons • Requires combining work • Requires DS and US spectrum availability • Moving to new DS requires new US • Outage could make CMs register on incorrect DS & affect registration times • CMs will need to be client-class processed with info in their DOCSIS config files • What if an US port dies?

  20. Option 2 - Separate CMTSs

  21. CMTS A CMTS B DS0 U0 U1 U2 U3 DS1 U0 U1 U2 U3 Option 2 - Diagram • Map US/DS ports from 2nd CMTS into existing nodes • Connect 2nd CMTS to core network • Provision Commercial CMs to proper freq & CMTS

  22. Option 2 - Pros • Hardware Isolation • More processing power • Future expansion and “poor-man’s” HA • Separates “high speed” customers for NOC “clarity” • Some systems use this for open access or to segregate Data form VoIP

  23. Option 2 - Cons • Second CMTS • Will CPU max out if one chassis dies? • More power draw & rack space in HE/hub • Must integrate 2nd chassis to network • Need address space for additional CMTS • CMs could lock on wrong CMTS & IP bundle • IP address depletion • Packet drops (no IM alignment between chassis) • CM offline on one CMTS & online on another

  24. Option 3 - Same as Option 1, but Utilizing ATDMA

  25. Option 3 - Same CMTS Utilizing ATDMA • Utilize ATDMA-only US ports for Commercial CMs • Only allows 2.0 CMs to "see" US port & register • Existing Res subs are blind to ATDMA port • Don't understand mac message 29 included in UCD • Need to configure provisioning to block Commercial CMs from registering on 1.x US port • Use provisioning to force specific DS freq or US Ch ID

  26. DS0 U0 U1 U2 U3 DS1 U0 U1 U2 U3 Option 3 - Diagram • DS0/U0 = TDMA (1.x mode) • DS1/U0 = ATDMA (2.0-only) • Only allows 2.0 CMs to "see" DS1/U0 & register on it

  27. DOCSIS 2.0 Benefits

  28. DOCSIS 2.0 – ATDMA Basics • Introduces “docsis-mode” concept: • TDMA (traditional 1.x mode) • ATDMA-TDMA (mixed 1.x and 2.0) • ATDMA (2.0-only) • Use “cable upstream x docsis-mode {}” to configure US channel to a desired mode • Automatically picks a new default mod profile

  29. DOCSIS 2.0 Benefits • Greater spectral efficiency • Better use of existing channels • More capacity • Provides higher throughput in US direction • Per-CM speed greater with better PPS • Robust against worst-case plant impairments • Although not part of spec, ingress cancellation allows higher orders of modulation • Opens unused portions of spectrum • Insurance for life-line services

  30. DOCSIS 2.0 Benefits • IUCs added for 1.x/2.0 mixed environment • 9 = a-short, 10 = a-long, 11 = a-ugs • Better statistical multiplexing • 6.4 MHz channel is better than 2, 3.2 channels • Increases US capacity to 30.72 Mbps • Enhances flexibility when used in combination with Virtual Interfaces • 1x1 MAC domain makes more sense

  31. DOCSIS 1.1 Phy Change (PRE-EQ) • US equalization is supported on all cards for 1.0 and 1.1 • 8-tap blind equalizer • 1.1 allows 'pre-equalization' where EQ coefficients are sent allowing a CM to pre-distort its signal • Cab up x equalization-coefficient • Supported on all linecards and releases that support 1.1 • Requires 1.1 capable CMs, but not .cm file • Configurable option • 2.0 increases the equalizer tap length from 8 to 24 • Supported on U cards in ATDMA mode • Off by default

  32. Amplitude Ripple/Tilt • 6.4 MHz ATDMA signal exhibits severe in-band tilt at US port • Pre-EQ in CM can compensate for nearly all tilt

  33. Option 3 – Pros and Cons

  34. Option 3 - Pros • Allows 2 stacked US channels • Only appears as one for Res customers • Allows less ports to be used since ATDMA USs operate at 27 Mbps usable speed • If spectrum is available, 2.0 CMs could use a 6.4 MHz channel & 64-QAM, if clean enough • Leverages 1 CMTS that’s already installed

  35. Option 3 - Cons • Requires new “high speed” users to have 2.0 CMs • Requires provisioning work to "block" 2.0 CMs from registering on Res freq • If Res subs buy their own 2.0 CMs, they could lock to commercial US w/o provisioning interdiction • Use TLV 39=0 for res CMs • Forces 1.x mode even if they are 2.0 capable • Can’t utilize load balancing • Configure mixed-mode with utilization-based LB • May require dynamic freq hopping or mod changes

  36. Cablevision’s Choice

  37. New Architecture Idea Using Option 3

  38. New Architecture Information • DS0-DS3 are 1x2 MAC domains – Regular Tier • DS4 is 1x8 MAC domain – Power Tier • USs use connector assignments & freq stacked • Boost Configuration: • US: Up to 27 Mbps per node • DS: ~25 Mbps @ 64-QAM or ~35 Mbps @ 256-QAM per 8 nodes • Could be further segmented down to 4 nodes • 4 US ports not used

  39. Questions to Answer • Back-office procedures & implementation, what happens when: • New CM registers on wrong DS • Catastrophic failure on entire node • Residential sub buys their own 2.0 CM • CMs move between DSs and/or US ports • Physical implementation • Is DS spectrum available for 256-QAM • Can US laser handle multiple carriers and higher modulation schemes

  40. CMTS Configuration

  41. Lab Testing Procedures and Verification • uBR10k with PRE1 running 12.3(9a)BC4 • Verified the following features: • Dual DS and US frequency to same node • Virtual Interfaces • ATDMA-only US • Frequency Stacking • 1x2 and 1x8 MAC domain • CM config file with specific DS freq configured • Used Cablevision’s CMTS config as much as possible • Broadband Access Center for Cable (BACC) used for provisioning, DHCP, ToD and TFTP

  42. interface Cable8/1/0 cable downstream modulation 256qam cable downstream frequency 603000000 cable downstream channel-id 0 cable downstream rf-power 58 cable upstream max-ports2 cable upstream 0 connector 0 shared cable upstream 0 frequency 25008000 cable upstream 0 channel-width 3200000 cable upstream 0 minislot-size 2 cable upstream 0 modulation-profile 23 no cable upstream 0 shutdown cable upstream 1 connector 2 shared cable upstream 1 frequency 25008000 cable upstream 1 channel-width 3200000 cable upstream 1 minislot-size 2 cable upstream 1 modulation-profile 23 no cable upstream 1 shutdown interface Cable8/1/4 cable downstream modulation 256qam cable downstream frequency 609000000 cable downstream channel-id 4 cable downstream rf-power 58 cable upstream max-ports8 cable upstream 0 connector 0 shared cable upstream 0 frequency 28496000 cable upstream 0 channel-width 3200000 cable upstream 0 minislot-size 2 cable upstream 0 modulation-profile 23 no cable upstream 0 shutdown cable upstream 1 connector 2 shared cable upstream 1 frequency 28496000 cable upstream 1 docsis-modeatdma cable upstream 1 channel-width 3200000 cable upstream 1 minislot-size 2 cable upstream 1 modulation-profile 221 no cable upstream 1 shutdown CMTS Linecard Configuration

  43. interface Cable8/1/1 cable downstream modulation 256qam cable downstream frequency 603000000 cable downstream channel-id1 cable downstream rf-power 58 cable upstream max-ports2 cable upstream 0 connector 4 shared cable upstream 0 frequency 25008000 cable upstream 0 channel-width 3200000 cable upstream 0 minislot-size 2 cable upstream 0 modulation-profile 23 no cable upstream 0 shutdown cable upstream 1 connector 6 shared cable upstream 1 frequency 25008000 cable upstream 1 channel-width 3200000 cable upstream 1 minislot-size 2 cable upstream 1 modulation-profile 23 no cable upstream 1 shutdown interface Cable8/1/4 cable downstream modulation 256qam cable downstream frequency 609000000 cable downstream channel-id4 cable downstream rf-power 58 cable upstream max-ports8 cable upstream 2 connector 4 shared cable upstream 2 frequency 28496000 cable upstream 2 channel-width 3200000 cable upstream 2 minislot-size 2 cable upstream 2 modulation-profile 23 no cable upstream 2 shutdown cable upstream 3 connector 6 shared cable upstream 3 frequency 28496000 cable upstream 3 channel-width 3200000 cable upstream 3 minislot-size 2 cable upstream 3 modulation-profile 23 no cable upstream 3 shutdown Configuration (cont)

  44. Concerns • IP Address Implications • How to prevent IP address exhaust during ranging onto incorrect DS freq • CM issues with multiple DS & US freqs? • Long time to register (CMs cache DS freq) • Power level when 2nd US freq added? • CMTS performs pwr on per-US freq & CW • Analog front-end could overload & cause harmonics • Per-CM speeds

  45. Concerns (cont) • Maybe laser clipping from adding additional freqs and higher modulation schemes • How to scale 1x8 and 1x2 MAC domains as utilization increases? • Take into account RF connections, provisioning, etc. • Bandpass filters in plant • US diplex filter range • 5-30, 5-40/42, 5-55, 5-65, …

  46. Another Idea to Utilize All “JIBs” DSs 0-3 = 603 MHz MC5x20 DS0 U0/C0 U1/C2 1x2 DS 4 = 609 MHz 1x8 DS4 U0/C0 U1/C2 U2/C4 U3/C16 U4/C8 U5/C10 U6/C12 U7/C18 DS Splitter 1x2 DS1 U0/C4 U1/C16 DS Combiner US Splitter • Requires: • 2 DS frequencies • 2 US freqs in each node • One US freq per DS • 4 US ports not used 1x2 DS2 U0/C8 U1/C10 1x2 DS3 U0/C12 U1/C18 All USs at 28.5 MHz All USs at 25 MHz

  47. Using All US Ports (4, 1x3s and 1, 1x8) DSs 0-3 = 453 MHz MC5x20 DS0 U0&1/C0 U2/C2 1x3 DS 4 = 459 MHz 1x8 DS4 U4/C2 U5/C6 U6/C10 U7/C14 U0/C16 U1/C17 U2/C18 U3/C19 DS Splitter 1x3 DS1 U0&1/C4 U2/C6 DS Combiner US Splitter • Requires: • 2 DS freqs • 3 US freqs in some nodes and only 2 in others 1x3 DS2 U0&1/C8 U2/C10 DS3 U0&1/C12 U2/C14 1x3 All USs at 28.5 MHz All USs at 25 MHz

  48. Cabling Ideas

  49. Maxnet II Picts

  50. Maxnet II Picts

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