Measuring Digital and DOCSIS Performance Randy Francis JDSU

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Measuring Digital and DOCSIS Performance Randy Francis JDSU

Measuring Digital and DOCSIS Performance Randy Francis JDSU

Today’s Agenda § Definitions / Background − − − § Digital Testing/Troubleshooting – –

Today’s Agenda § Definitions / Background − − − § Digital Testing/Troubleshooting – – – § Voice Quality Measurements, E-Model, Delay, Packet Loss, Jitter Vo. IPCheck Testing, Packet. Cable Testing Return Path – – – 2 Packet Loss, Throughput Vo. IP Testing – – § MER, BER, QAM Ingress, Equalizer Stress, C/N vs. BER vs. MER Constellations / Symbols and Digital Bits, Phase Noise DOCSIS & IP Testing – § Digital Signals / QAM DOCSIS 1, 1. 1, 2. 0. 3. 0 (Data Over Cable Service Interface Spec. ) Vo. IP Why monitor it? RF Trending Results Ingress & Leakage § Q and A § Quiz Time © 2006 JDSU. All rights reserved. JDSU CONFIDENTIAL & PROPRIETARY INFORMATION

Acronyms & Terms § QAM § Symbols § Symbol Rate §I&Q § Constellation §

Acronyms & Terms § QAM § Symbols § Symbol Rate §I&Q § Constellation § MER § BER § FEC 3 © 2006 JDSU. All rights reserved. - Quadrature Amplitude Modulation - Collection of Bits - Transmission Speed - Components of QAM data - Graph of QAM Data - Modulation Error Ratio - Bit Error Rate - Forward Error Correction JDSU CONFIDENTIAL & PROPRIETARY INFORMATION

A Typical Home Installation a typical home installation TAP House TV Drop Cable GROUND

A Typical Home Installation a typical home installation TAP House TV Drop Cable GROUND BLOCK High Pass Filter 2 -Way Splitter TV 3 -Way Splitter TV CABLE MODEM 4 © 2006 JDSU. All rights reserved. JDSU CONFIDENTIAL & PROPRIETARY INFORMATION

Why Go Digital? § Efficiency – Source signals are digital • Standard and High

Why Go Digital? § Efficiency – Source signals are digital • Standard and High Definition TV (SDTV, HDTV) – High Speed Data and Digital Video is more efficient than analog • Transmit equivalent of 6 to 10 analog channels (VCR quality) over one 6 MHz bandwidth § Quality – Better Picture and Sound Quality – Less Susceptible to noise • Error detection and correction is possible § Flexibility – Data easily multiplexed into digital signal – Higher Data Security 5 © 2006 JDSU. All rights reserved. JDSU CONFIDENTIAL & PROPRIETARY INFORMATION

What is Digital? § Source and Destination is digital data – Assign unique patterns

What is Digital? § Source and Destination is digital data – Assign unique patterns of 1’s and 0’s § Transmission path is via an analog carrier – Choice of modulation is the one that optimizes bandwidth (data versus frequency ‘space’) and resiliency to noise 00 01 10 11 00 Generate Digital © 2006 JDSU. All rights reserved. 10 Receive Digital Transmit Analog 6 01 JDSU CONFIDENTIAL & PROPRIETARY INFORMATION 11

The Carrier, by the way, is ANALOG Modulation Analog Content – Analog Carrier Digital

The Carrier, by the way, is ANALOG Modulation Analog Content – Analog Carrier Digital Content – Analog Carrier 7 © 2006 JDSU. All rights reserved. JDSU CONFIDENTIAL & PROPRIETARY INFORMATION

Some good news…and some bad news § Good § Bad – Digital TV, DOCSIS,

Some good news…and some bad news § Good § Bad – Digital TV, DOCSIS, Digital Voice all use SAME type of RF Modulation – QAM – Same measurements apply – Signal level, Modulation Error Ratio, Bit Error Rate, in-band frequency response, are all similar, if not identical. 8 © 2006 JDSU. All rights reserved. – Each service has different threshold of impairments – What is noticeable in Digital voice may not be perceptible in DOCSIS, what is bothersome in DOCSIS is different than digital video. JDSU CONFIDENTIAL & PROPRIETARY INFORMATION

QAM and CATV § 16 QAM is part of the DOCSIS® 1. 0/1. 1

QAM and CATV § 16 QAM is part of the DOCSIS® 1. 0/1. 1 upstream specifications § 64 QAM and 256 QAM is used for both digital video and DOCSIS downstream, allowing more digital data transmission using the same 6 MHz bandwidth – Transmit equivalent of 6 to 10 analog channels (VCR quality) over one 6 MHz bandwidth § DOCSIS is the Standard for data over Cable – Cable systems provide higher signal to noise ratios than over-theair transmission. A well designed and maintained cable plant meets these QAM signal to noise requirements. 9 © 2006 JDSU. All rights reserved. JDSU CONFIDENTIAL & PROPRIETARY INFORMATION

QAM Data Capacity (Annex B) Symbol Rate (Msps) 10 16 QAM 64 QAM 256

QAM Data Capacity (Annex B) Symbol Rate (Msps) 10 16 QAM 64 QAM 256 QAM (Upstream) (Downstream) 2. 560 5. 0569 5. 3605 (@ 6 MHz) (@ 3. 20 MHz) Bits per symbol 4 6 8 Channel Data Rate (Mbps) 10. 24 30. 3417 42. 8843 Actual Information bit rate (Mbps) 9. 0 26. 9704 38. 8107 Overhead 12. 11% 11. 11% 9. 5% © 2006 JDSU. All rights reserved. QAM 256 allows ~ 2 more channels vs. QAM 64 No Real Cost Advantages Why not go all QAM 256? JDSU CONFIDENTIAL & PROPRIETARY INFORMATION

DOCSIS® What is it? What differs among versions?

DOCSIS® What is it? What differs among versions?

DOCSIS Defined? § DOCSIS Definition – Cable. Labs® Certified Cable Modem Project • Data

DOCSIS Defined? § DOCSIS Definition – Cable. Labs® Certified Cable Modem Project • Data Over Cable Service Interface Specification – Not required but highly adhered to standard – allows interoperability § Data over a digital QAM signal – Digital signal • Downstream usually 64 or 256 QAM • Upstream usually QPSK or 16 QAM – Uses Data Packets • Information broken into chunks – Asymmetrical communication • More Info Downstream • Less Info Upstream Digital “haystack” 12 © 2006 JDSU. All rights reserved. JDSU CONFIDENTIAL & PROPRIETARY INFORMATION

DOCSIS® Versions at a Glance DOCSIS 1. 0 (High Speed Internet Access) – 23

DOCSIS® Versions at a Glance DOCSIS 1. 0 (High Speed Internet Access) – 23 million products shipped worldwide as of YE 2002 – 228 CM Certified, 29 CMTS Qualified DOCSIS 1. 1 (Voice, Gaming, Streaming) –Interoperable and backwards-compatible with DOCSIS 1. 0 –“Quality of Service” and dynamic services, a MUST for Packet. Cable™ –In the field NOW - 64 CM Certified, 22 CMTS Qualified DOCSIS 2. 0 (Capacity for Symmetric Services) –Interoperable and backwards compatible with DOCSIS 1. x –More upstream capacity than DOCSIS 1. 0 (x 6) & DOCSIS 1. 1 (x 3) –Improved robustness against interference (A-TDMA and S-CDMA) –Available NOW – Number of CM & CMTS Qualified growing DOCSIS 3. 0 (Channel Bonding) –Interoperable and backwards compatible with DOCSIS 1. x & 2. 0 –Specification released earlier this month – Devices not yet available Good Resource Site: www. cablelabs. org 13 © 2006 JDSU. All rights reserved. JDSU CONFIDENTIAL & PROPRIETARY INFORMATION

DOCSIS 1. 1 Overview § Interoperable with DOCSIS 1. 0, plus more… § Enhanced

DOCSIS 1. 1 Overview § Interoperable with DOCSIS 1. 0, plus more… § Enhanced “Quality of Service” (Qo. S) – Guarantees and/or limits for data rates • (ex. Gold, Silver service levels) – Guarantees for latency § Improved security - designed to reduce possibility of “theft of service, provide secure software downloading. ” – BPI+ (Baseline Privacy Plus) § Interoperability - DOCSIS 1. 0 and DOCSIS 1. 1 cable modems and CMTSs on the same plant. Better operation and OSS features § Transmit Equalization - more robust transmission § Max Modulation – 256 QAM Downstream (~40 Mbps) – 16 QAM Upstream @ 3. 2 MHz (~10 Mbps) 14 © 2006 JDSU. All rights reserved. JDSU CONFIDENTIAL & PROPRIETARY INFORMATION

DOCSIS 2. 0 Overview – Key Upstream Advances § Symmetrical services are enabled by

DOCSIS 2. 0 Overview – Key Upstream Advances § Symmetrical services are enabled by DOCSIS 2. 0 – 1. 5 x greater efficiency • operates at 64 QAM – 2 x wider channels • new 6. 4 MHz wide channel § 3 x better upstream performance than V 1. 1 § 6 x better upstream performance than V 1. 0 § DOCSIS 2. 0 widens the pipe for IP traffic, allowing cable providers to create more and better services for voice, video, and data – It does this by using enhanced modulation and improved error correction § Superior ingress and impulse noise performance § 100% backward compatible with DOCSIS 1. 0/1. 1 15 © 2006 JDSU. All rights reserved. JDSU CONFIDENTIAL & PROPRIETARY INFORMATION

DOCSIS 3. 0 Overview § Specification late last year – DOCSIS 3. 0 Interface

DOCSIS 3. 0 Overview § Specification late last year – DOCSIS 3. 0 Interface Specifications (Released December 2006) – CPE equipment in development stages § Downstream data rates of 160 Mbps or higher – Channel Bonding – 4 or more channels 256 QAM => ~40 Mbps 4 x 256 QAM => ~160 Mbps § Upstream data rates of 120 Mbps or higher – Channel Bonding – 4 or more channels 64 QAM => ~30 Mbps 4 x 64 QAM => ~120 Mbps § Internet Protocol version 6 (IPv 6) § 16 – Current System (IPv 4) is limited to 4. 3 B numbers – IPv 6 greatly expands the number of IP addresses • Expands IP address size from 32 bits to 128 bits • IPv 6 supports 3. 4× 1038 addresses; 4923: 2 A 1 C: 0 DB 8: 04 F 3: AEB 5: 96 F 0: E 08 C: FFEC • Colon-Hexadecimal Format 100% backward compatible with DOCSIS 1. 0/1. 1/2. 0 © 2006 JDSU. All rights reserved. JDSU CONFIDENTIAL & PROPRIETARY INFORMATION

DOCSIS 3. 0 – Channel Bonding Individual QAM 256 DOCSIS channel Versions 1. 0/1.

DOCSIS 3. 0 – Channel Bonding Individual QAM 256 DOCSIS channel Versions 1. 0/1. 1/2. 0 used only one channel for upstream and one channel for downstream communications 256 QAM => ~40 Mbps 4 Bonded QAM 256 DOCSIS channels DOCSIS v 3. 0 Spec requires devices to be able to bond a minimum of 4 upstream channels into one and 4 downstream channels into one for 4 times increased throughput in both directions The MSO does not have to use all 4 channels, but the devices which are 3. 0 compliant must have the ability to bond 4 or more channels in both directions 4 x 256 QAM: 4 x 40 Mbps = 160 Mbps 17 © 2006 JDSU. All rights reserved. JDSU CONFIDENTIAL & PROPRIETARY INFORMATION

Digital Testing and Troubleshooting How? What does it mean?

Digital Testing and Troubleshooting How? What does it mean?

QAM Digital Measurements § Spectrum & Digital Average Power Level § MER QAM §

QAM Digital Measurements § Spectrum & Digital Average Power Level § MER QAM § Pre/Post FEC BER § Constellation Display § Advanced Tests – – 19 QAM Ingress Under The Carrier Group Delay In-Channel Frequency Response Equalizer Stress (Adaptive Equalization) © 2006 JDSU. All rights reserved. JDSU CONFIDENTIAL & PROPRIETARY INFORMATION

QAM Digital Measurements § Measuring the quality of QAM digital carriers is significantly different

QAM Digital Measurements § Measuring the quality of QAM digital carriers is significantly different than measuring analog carriers. § Measurement of digital carriers is important to determine how close the carrier is to failing (how much margin) since there may be no quality degradation. 20 © 2006 JDSU. All rights reserved. JDSU CONFIDENTIAL & PROPRIETARY INFORMATION

Digital Average Power Level Measurements Digital Average Power Measurements and Measurement Bandwidth § The

Digital Average Power Level Measurements Digital Average Power Measurements and Measurement Bandwidth § The spectrum analyzer view is an excellent tool to see discreet RF-carriers. – Caution is needed when viewing digital modulated signals (haystack). The signal’s level measurement is derived from the selected measurement bandwidth (resolution bandwidth). At an RBW of 300 k. Hz, a 64 QAM - 6 MHz wide digital signal reads in the spectrum analyzer trace 3 d. B too low. § The Average Power principle takes small slices from the integrated RFenergy, summing them together to one total power reading in the LEVEL-mode. 21 © 2006 JDSU. All rights reserved. Analog and digital (broadcast) QAM signal. The recommended delta in level should be 6 to 10 d. B. JDSU CONFIDENTIAL & PROPRIETARY INFORMATION

Measuring the Digital “Haystack” Non measured area based on 280 k. Hz step size

Measuring the Digital “Haystack” Non measured area based on 280 k. Hz step size within 6 MHz total Bandwidth Digital carrier under test (6 MHz BW) IF Measurement Bandwidth = 280 k. Hz Summing slices of the total integrated energy 0 -2. 5 MHz Frequency +/- 140 k. Hz 22 © 2006 JDSU. All rights reserved. JDSU CONFIDENTIAL & PROPRIETARY INFORMATION +2. 5 MHz

Measuring the Digital “Haystack” 23 Measuring the Peak Level of the Digital Haystack Measuring

Measuring the Digital “Haystack” 23 Measuring the Peak Level of the Digital Haystack Measuring the Average Level of the Digital Haystack 280 k. Hz Bandwidth power 6 MHz Bandwidth power © 2006 JDSU. All rights reserved. JDSU CONFIDENTIAL & PROPRIETARY INFORMATION

Digital – more than just d. B’s MER and Pre and Post BER measurements

Digital – more than just d. B’s MER and Pre and Post BER measurements are key to insuring Digital Quality 24 © 2006 JDSU. All rights reserved. JDSU CONFIDENTIAL & PROPRIETARY INFORMATION

Modulation Error Ratio (MER) § Analogous to S/N § A measure of how symbols

Modulation Error Ratio (MER) § Analogous to S/N § A measure of how symbols (I vs. Q) are actually placed, compared to ideal placement § MER(d. B) = 20 x log RMS error magnitude average symbol magnitude § Good MER – 64 QAM: 28 d. B MER – 256 QAM: 32 d. B MER Average symbol magnitude RMS error magnitude 25 © 2006 JDSU. All rights reserved. JDSU CONFIDENTIAL & PROPRIETARY INFORMATION

More MER § Modulation Error Ratio (MER) in digital systems is similar to S/N

More MER § Modulation Error Ratio (MER) in digital systems is similar to S/N or C/N used in analog systems § MER determines how much margin the system has before failure – Analog systems that have a poor C/N show up as a “snowy” picture – A poor MER is noticeable on the picture right up to the point of system failure - “Cliff Effect” § Can’t use the TV as a piece of test equipment anymore 26 © 2006 JDSU. All rights reserved. JDSU CONFIDENTIAL & PROPRIETARY INFORMATION

Digital TV Waterfall Graph 27 © 2006 JDSU. All rights reserved. JDSU CONFIDENTIAL &

Digital TV Waterfall Graph 27 © 2006 JDSU. All rights reserved. JDSU CONFIDENTIAL & PROPRIETARY INFORMATION

C/N vs. BER vs. MER No FEC 28 © 2006 JDSU. All rights reserved.

C/N vs. BER vs. MER No FEC 28 © 2006 JDSU. All rights reserved. JDSU CONFIDENTIAL & PROPRIETARY INFORMATION

Lets have some MER review… § “MER” is to Digital, what signal to noise

Lets have some MER review… § “MER” is to Digital, what signal to noise is for analog § MER is affected by high noise, low signal § Also ANY other continuous impairments § MER readings are relatively immune to “brief bursty” interference § MER is a predictor of BER 29 © 2006 JDSU. All rights reserved. Some Guidelines for MER – 64 QAM - 28 d. B or better – 256 QAM - 32 d. B or better Try to add at least 3 db to above figures to allow headroom. JDSU CONFIDENTIAL & PROPRIETARY INFORMATION

Bit Error Rate (BER) § Bit errors result when the receiver interprets the wrong

Bit Error Rate (BER) § Bit errors result when the receiver interprets the wrong symbol and hence the wrong bits § The number of bit errors versus the number of bits transmitted is Bit Error Rate (BER) § The more bits that are incorrect, the more the signal will be affected § Good signal: BER 10 -10 (1. 0 E-9) § Threshold for visible degradation: BER 1 E-6 – One error in every 1, 000 bits 30 © 2006 JDSU. All rights reserved. JDSU CONFIDENTIAL & PROPRIETARY INFORMATION

More on BER § “BER” is HOW many § Some amount of errors per

More on BER § “BER” is HOW many § Some amount of errors per HOW many bits can be corrected by of data digital receivers. (PRE errors) § BER is affected by bursty interference § POST errors are uncorrected errors – § Also, any other always unacceptable!!! impairments will adversely affect BER § Measurement reads in scientific notation § 1. 0 E-9 is the best on a handheld test meter 31 © 2006 JDSU. All rights reserved. JDSU CONFIDENTIAL & PROPRIETARY INFORMATION

Pre and Post FEC BER § Number of bad bits for every good bit.

Pre and Post FEC BER § Number of bad bits for every good bit. § Forward Error Correction when working will output >10 -11 – 1 error in 100 billion bits – 1 error every 42 minutes – MPEG-2 likes good BER § FEC will work to about 10 -4 – 1 error in 10, 000 bits – 1 error every 276 uses QAM 256 42 Mb/s § FEC can correct BER from 1 -E-4 to 1 E-9 § FEC causes Cliff Effect 32 © 2006 JDSU. All rights reserved. JDSU CONFIDENTIAL & PROPRIETARY INFORMATION

BER Example § A 256 QAM channel transmits at a symbol rate of 5

BER Example § A 256 QAM channel transmits at a symbol rate of 5 M symbols per second § Bit rate = 8 bits per symbol X 5 M symbol per second =40 M bits per second § Error Incident = Bit rate X BER = Errors Per Second 33 © 2006 JDSU. All rights reserved. JDSU CONFIDENTIAL & PROPRIETARY INFORMATION

What Causes MER and BER to degrade? “ Noise” § The most common problem

What Causes MER and BER to degrade? “ Noise” § The most common problem with digital-TV and cable modem services is interference under the digital carriers and Noise(stated by most larger operators with experience in digital transmission services). § Most common sources are: – Ingress due to off-air UHF TV channels – Intermittent ingress due to pager transmitters or two-way radio base stations. – Cracked or broken cables – CSO/CTB-intermodulation – • due to unterminated TAPs or impedance mismatch – Laser Clipping 34 © 2006 JDSU. All rights reserved. JDSU CONFIDENTIAL & PROPRIETARY INFORMATION

QAM Constellations 35 © 2006 JDSU. All rights reserved. JDSU CONFIDENTIAL & PROPRIETARY INFORMATION

QAM Constellations 35 © 2006 JDSU. All rights reserved. JDSU CONFIDENTIAL & PROPRIETARY INFORMATION

Constellations, Symbols and Digital Bits § Each “dot” on constellation represents a unique symbol

Constellations, Symbols and Digital Bits § Each “dot” on constellation represents a unique symbol § Each unique symbol represents unique digital bits § Digital data is parsed into data lengths that encode the symbol waveform 16 QAM 36 © 2006 JDSU. All rights reserved. JDSU CONFIDENTIAL & PROPRIETARY INFORMATION

Constellation Display § This is a visual representation of the I and Q constellation

Constellation Display § This is a visual representation of the I and Q constellation plots on a 16 QAM carrier 38 © 2006 JDSU. All rights reserved. JDSU CONFIDENTIAL & PROPRIETARY INFORMATION

64 QAM and 256 QAM § 64 QAM has 8 levels of I and

64 QAM and 256 QAM § 64 QAM has 8 levels of I and 8 levels of Q making 64 possible locations for the carrier. § 256 QAM has 16 levels of I and 16 levels of Q making 256 possible locations for the carrier. § QAM 256 is somewhat less robust vs. QAM 64 8 Levels of Q Channel 39 © 2006 JDSU. All rights reserved. JDSU CONFIDENTIAL & PROPRIETARY INFORMATION 16 Levels of Q Channel 16 Levels of I Channel 8 Levels of I Channel

Effects of Noise and Interference § Noise and Interference moves the carrier away from

Effects of Noise and Interference § Noise and Interference moves the carrier away from its ideal location causing a spreading of the cluster of dots. Ideal Locations 40 © 2006 JDSU. All rights reserved. JDSU CONFIDENTIAL & PROPRIETARY INFORMATION

Decision Boundaries § Data that falls outside the decision boundaries will be assumed to

Decision Boundaries § Data that falls outside the decision boundaries will be assumed to be the adjacent data. Data Received Correctly Q I Decision Boundary 41 © 2006 JDSU. All rights reserved. JDSU CONFIDENTIAL & PROPRIETARY INFORMATION Error

Constellation § Typical errors which originate from the headend: – Phase Noise • The

Constellation § Typical errors which originate from the headend: – Phase Noise • The constellation appears to be rotating at the extremes while the middle ones remain centered in the decision boundaries. Phase Noise is caused by headend converters. – Gain Compression • The outer dots on the constellation are pulled into the center while the middle ones remain centered in the decision boundaries. Gain Compression is caused by filters, IF equalizers, converters, and amplifiers. – I Q Imbalance • The constellation is taller than it is wide. This is a difference between the gain of the I and Q channels. I Q Imbalance is caused by baseband amplifiers, filters, or the digital modulator. – Carrier Leakage 42 © 2006 JDSU. All rights reserved. JDSU CONFIDENTIAL & PROPRIETARY INFORMATION

System Noise and/or Leakage Issues § A constellation displaying significant noise § Dots are

System Noise and/or Leakage Issues § A constellation displaying significant noise § Dots are spread out indicating high noise and most likely significant errors – An error occurs when a dot is plotted across a boundary and is placed in the wrong location § Meter will not lock if too much noise present Dots are spread out showing error 43 © 2006 JDSU. All rights reserved. JDSU CONFIDENTIAL & PROPRIETARY INFORMATION

Phase Noise § Display appears to rotate at the extremes § HE down/up converters

Phase Noise § Display appears to rotate at the extremes § HE down/up converters can cause phase noise § Random phase errors cause decreased transmission margin § Caused by transmitter symbol clock jitter Rotation Constellation with Phase Noise Rotation Zoomed Constellation with Phase Noise Key Cause: Converter within the HE (garbage in produces garbage out) 44 © 2006 JDSU. All rights reserved. JDSU CONFIDENTIAL & PROPRIETARY INFORMATION

Gain Compression § If the outer dots are pulled into the center while the

Gain Compression § If the outer dots are pulled into the center while the middle ones are not affected, the signal has gain compression § Gain compression can be caused by IF and RF amplifiers and filters, up/down converters and IF equalizers – May be caused by line amps or laser clipping – Not a customer issue – maintenance techs issue Outer edges pulled in 45 © 2006 JDSU. All rights reserved. JDSU CONFIDENTIAL & PROPRIETARY INFORMATION

Coherent Interference § If the accumulation looks like a “donut”, the problem is coherent

Coherent Interference § If the accumulation looks like a “donut”, the problem is coherent interference – CTB, CSO, Off-Air Carriers (ingress) § Sometimes only a couple dots will be misplaced – This is usually laser clipping or sweep interference Circular “donuts” 46 © 2006 JDSU. All rights reserved. JDSU CONFIDENTIAL & PROPRIETARY INFORMATION

DOCSIS & IP Testing What is important? What can be done?

DOCSIS & IP Testing What is important? What can be done?

DOCSIS® Testing - Levels Verify proper receive level at cable modem Should be seeing:

DOCSIS® Testing - Levels Verify proper receive level at cable modem Should be seeing: 0 d. Bm. V Pass/Fail Indicator: Downstream Information Frequency, Modulation type, Channel MER shows that downstream is clean and clear with margin BER shows that downstream is clean and clear of impulse noise 48 © 2006 JDSU. All rights reserved. Upstream Frequency, Modulation type, Channel BW, DOCSIS version Shows that upstream is properly aligned and CMTS has “ideal” receive level with margin to spare. Recommend: (35 d. Bm. V – 45 d. Bm. V) JDSU CONFIDENTIAL & PROPRIETARY INFORMATION

DOCSIS – Packet Loss Testing Check Packet Loss and determine if upstream is good

DOCSIS – Packet Loss Testing Check Packet Loss and determine if upstream is good Overall loop information, Up+Downstreams View Downstream performance 49 © 2006 JDSU. All rights reserved. JDSU CONFIDENTIAL & PROPRIETARY INFORMATION Upstream Signal to Noise Ratio

DOCSIS – Throughput Testing Check Throughput for proper speeds Config. File Ensure customer can

DOCSIS – Throughput Testing Check Throughput for proper speeds Config. File Ensure customer can get what they pay for 50 © 2006 JDSU. All rights reserved. JDSU CONFIDENTIAL & PROPRIETARY INFORMATION

Correlate Data & Voice with RF Compare Node Outages with your Return Path performance

Correlate Data & Voice with RF Compare Node Outages with your Return Path performance history to QUICKLY identify the cause of the problem – RF or Data layer! HSD Node Outage Report Courtesy of Auspice Corporation 51 © 2006 JDSU. All rights reserved. JDSU CONFIDENTIAL & PROPRIETARY INFORMATION

Vo. IP Testing Why is it important? What can be done?

Vo. IP Testing Why is it important? What can be done?

Vo. IP – Bullet Train Analogy § Ideal World: – Packets like train Cars

Vo. IP – Bullet Train Analogy § Ideal World: – Packets like train Cars through a station – 1 at a time, evenly spaced, and Fast • Bullet Train… • Cold & Refreshing… 53 © 2006 JDSU. All rights reserved. JDSU CONFIDENTIAL & PROPRIETARY INFORMATION

Vo. IP – Train Analogy § Real World – Vo. IP Packets don’t always

Vo. IP – Train Analogy § Real World – Vo. IP Packets don’t always do what you want… • Multiple railcars taking different directions, uneven spacing • Missing railcars… all = TRAIN WRECK! 54 © 2006 JDSU. All rights reserved. JDSU CONFIDENTIAL & PROPRIETARY INFORMATION

Voice Quality - Measures § Models to Answer: “Does it ‘Sound Good’? ” –

Voice Quality - Measures § Models to Answer: “Does it ‘Sound Good’? ” – International Telecommunications Union (ITU) has multiple models • Subjective (Opinion of users) – Mean Opinion Score (MOS) » » Defacto standard ‘score’ “Judged” summary of call quality In-service test, can be used on live network Algorithms have replaced but mimic opinionated scores • Objective (Not an opinion) – Perceptual Analysis/Measurement System (PAMS) and Perceptual Evaluation of Speech Quality (PESQ) » Not based on network issues: Packet loss, Jitter and Delay » Do not factor in end-to-end delay » Require HW probes » (Not used for in-service testing) – E-Model, R-Value » Addresses all issues with PAMS and PESQ particularly as it places focus on Packet loss, Jitter, and Delay 55 © 2006 JDSU. All rights reserved. JDSU CONFIDENTIAL & PROPRIETARY INFORMATION

Voice Quality - E-Model § E-Model R-Value – Most complete, objective test R =

Voice Quality - E-Model § E-Model R-Value – Most complete, objective test R = Ro + A – Ls – Ld – Le • Ro: Basic SNR or circuits – handsets, environment • A: Advantage Factor – GSM poor service, example. • Ls: Simultaneous impairment factor – loudness/volume, hissing, sidetone, quantization distortion • Ld: Talker/listener echo, Overall Delay • Le: Equipment impairment factor – Packet loss, Jitter Things you will take action on! 56 © 2006 JDSU. All rights reserved. JDSU CONFIDENTIAL & PROPRIETARY INFORMATION

Delay, Packet Loss and Jitter- What is it? § Delay X-Time D C B

Delay, Packet Loss and Jitter- What is it? § Delay X-Time D C B A Network Point A Point B – Time it takes a packet to ‘transverse’ the network • Point A to Point B – Time it takes is shown here as ‘X’ – Too much delay affects the quality of a call • See this on PSTN with international calls (Over-talk) • Echo (More delay = more potential echo) – Usually an architecture (traffic/capacity) issue • Longer distances and more routers add delay • Too many calls/downloads add delay (slows routers) • Generally not a HFC issue with equipment such as amplifiers 57 © 2006 JDSU. All rights reserved. JDSU CONFIDENTIAL & PROPRIETARY INFORMATION

Delay, Packet Loss and Jitter- What is it? § Packet Loss ∞ -Time X-Time

Delay, Packet Loss and Jitter- What is it? § Packet Loss ∞ -Time X-Time D C B A Network Point A Point B – Packet did not arrive (Point B) or out of sequence • Vo. IP telephony is different than data – If it was out of order, computer reorders for data – If lost, just retransmit data – Shown here as infinite time – did not show up – Worse if it is ‘bursty’, many lost in a row – “lossy” – Can be architecture or physical layer • Ingress (especially upstream) • Routers over capacity (too full to hold any more) 58 © 2006 JDSU. All rights reserved. JDSU CONFIDENTIAL & PROPRIETARY INFORMATION

Delay, Packet Loss and Jitter- What is it? § Jitter X-Time D C B

Delay, Packet Loss and Jitter- What is it? § Jitter X-Time D C B A Point A Network D A B C Point B Slower than X Faster than X – Packets not arriving at the same time (different from XTime) – time between packets is different • Different than data – You never notice with Data, doesn’t matter how the information arrives, just care that it shows up – Vo. IP is Real-Time • Key Causes – IP based equipment having packet routing issues 59 © 2006 JDSU. All rights reserved. JDSU CONFIDENTIAL & PROPRIETARY INFORMATION

Packet Knowledge D C B A Point B FULL Z 60 © 2006 JDSU.

Packet Knowledge D C B A Point B FULL Z 60 © 2006 JDSU. All rights reserved. JDSU CONFIDENTIAL & PROPRIETARY INFORMATION

Jitter – A problem? § Creates two problems – Direct speech quality • Part

Jitter – A problem? § Creates two problems – Direct speech quality • Part is FF, part is normal, part is ‘Slow’ – Could result in Packet Loss • Walk on top of packets if some are slow and consecutive ones are fast. D CB A X-Time Slower than X Faster than X Slower than X – Could be capacity, physical or core architecture • Routers spitting out packets at varying intervals • Packets take different routes to destination 61 © 2006 JDSU. All rights reserved. JDSU CONFIDENTIAL & PROPRIETARY INFORMATION

Jitter – Solution? § Jitter Buffer – Add a place to store the data,

Jitter – Solution? § Jitter Buffer – Add a place to store the data, and ‘spit’ it out at a constant rate • If packets come in fast – slow them down • Packets are slow – OK, we have added time to allow for this Jitter Buffer D Point B Slower than X CB A D X-Time Slower than X Faster than X C B Y-Delay • Very similar to Windows Media Player Buffer bar 62 © 2006 JDSU. All rights reserved. JDSU CONFIDENTIAL & PROPRIETARY INFORMATION A

Jitter Buffer – Problem Solved? § Yes and No – We have taken care

Jitter Buffer – Problem Solved? § Yes and No – We have taken care of jitter (that isn’t extreme), but have added delay: Y (buffer size) • If packets come in fast – slow them down • Packets are slow – OK, we have added time to allow for this X-Time D C B A Y-Delay D C B A Just Right § Dynamic Jitter Buffer § Self adjusting buffer, based on system conditions which optimizes the jitter buffer 63 © 2006 JDSU. All rights reserved. D C JDSU CONFIDENTIAL & PROPRIETARY INFORMATION B A

Jitter Buffer – Tradeoffs § Too large – Too much delay § Too small

Jitter Buffer – Tradeoffs § Too large – Too much delay § Too small – Have jitter – Have packet loss § Just Right – Dynamic Jitter Buffer • Can set this option so the system will monitor and optimize the jitter buffer 64 © 2006 JDSU. All rights reserved. JDSU CONFIDENTIAL & PROPRIETARY INFORMATION

Vo. IPCheck™ over DOCSIS® § HFC Performance – Packet Statistics • Packet loss •

Vo. IPCheck™ over DOCSIS® § HFC Performance – Packet Statistics • Packet loss • Delay • Jitter – Vo. IP Quality • MOS • R-Value – Test Result Totals • • 65 Current Min Max Average © 2006 JDSU. All rights reserved. JDSU CONFIDENTIAL & PROPRIETARY INFORMATION

Vo. IPCheck™ over DOCSIS® § Segment HFC and IP impairments § Quick quality (MOS)

Vo. IPCheck™ over DOCSIS® § Segment HFC and IP impairments § Quick quality (MOS) verification of Vo. IP over DOCSIS® channel § Good to check Vo. IP packet statistics 66 © 2006 JDSU. All rights reserved. JDSU CONFIDENTIAL & PROPRIETARY INFORMATION

Vo. IP Testing Based on Cable. Labs™ Packet. Cable™ Standard Place and test the

Vo. IP Testing Based on Cable. Labs™ Packet. Cable™ Standard Place and test the Quality of a Packet. Cable® Based Vo. IP Call to validate In-Service performance Measure Performance Statistics – – 67 Packet Loss Total “End to End” Delay (ms) Jitter MOS & R-Value © 2006 JDSU. All rights reserved. JDSU CONFIDENTIAL & PROPRIETARY INFORMATION

Segmented Error Budgets 68 © 2006 JDSU. All rights reserved. JDSU CONFIDENTIAL & PROPRIETARY

Segmented Error Budgets 68 © 2006 JDSU. All rights reserved. JDSU CONFIDENTIAL & PROPRIETARY INFORMATION

Wrap-Up

Wrap-Up

Troubleshooting is “Back to the Basics” § § § § Majority of problems are

Troubleshooting is “Back to the Basics” § § § § Majority of problems are basic physical layer issues Most of the tests remain the same Check power Check forward levels, analog and digital Check forward / reverse ingress Do a visual check of connectors / passives Replace questionable connectors / passives Tighten F-connectors per your company’s installation policy – Be very careful not to over tighten connectors on CPE (TVs, VCRs, converters etc. ) and crack or damage input RFI integrity 70 © 2006 JDSU. All rights reserved. JDSU CONFIDENTIAL & PROPRIETARY INFORMATION

Common problems typically identified in outside plant § Damaged or missing end-of-line terminators. §

Common problems typically identified in outside plant § Damaged or missing end-of-line terminators. § Damaged or missing chassis terminators on directional coupler, splitter or multiple-output amplifier unused ports. § Loose center conductor seizure screws. § Unused tap ports not terminated. This is especially critical on lower value taps. § Unused drop passive ports not terminated. § Use of so-called self-terminating taps (4 d. B two port; 8 d. B four port and 10/11 d. B eight port) at feeder ends -of-line. Such taps are splitters, and do not terminate the line unless all F ports are properly terminated. 71 © 2006 JDSU. All rights reserved. JDSU CONFIDENTIAL & PROPRIETARY INFORMATION

Common problems typically identified in outside plant § Kinked or damaged cable (including cracked

Common problems typically identified in outside plant § Kinked or damaged cable (including cracked cable, which causes a reflection and ingress). § Defective or damaged actives or passives (waterdamaged, water-filled, cold solder joint, corrosion, loose circuit-board screws, etc. ). § Cable-ready TVs and VCRs connected directly to the drop. (Return loss on most cable-ready devices is poor. ) § Some traps and filters have been found to have poor return loss in the upstream, especially those used for data-only service. 72 © 2006 JDSU. All rights reserved. JDSU CONFIDENTIAL & PROPRIETARY INFORMATION

Quiz Time

Quiz Time

Quiz Time 1. Define DOCSIS and QAM 2. What is the visual difference in

Quiz Time 1. Define DOCSIS and QAM 2. What is the visual difference in an analog channel vs. digital channel on a spectrum analyzer. How many channels can you get in a digital 6 MHz b/w? 3. When would someone use QAM 256 modulation vs. QAM 64? Why not use all QAM 256 modulation? 4. What’s the data rate expected for DOCSIS 3. 0? Distinguish between Downstream and Upstream. What new technology enables this larger data rate? Please explain. 5. How many IP addresses will IPv 6 provide? 74 © 2006 JDSU. All rights reserved. JDSU CONFIDENTIAL & PROPRIETARY INFORMATION

Quiz Time con’t. 6. Why doesn’t Peak Level Power = Ave Digital Power? 7.

Quiz Time con’t. 6. Why doesn’t Peak Level Power = Ave Digital Power? 7. Define MER and BER. Why do we use Constellation Diagrams? 8. What are 2 good DOCSIS Tests? 9. What are 3 things to check when testing Vo. IP? What are 2 accepted “scorings” used in the industry? 10. What type testing should be done on the Reverse Path? 11. Why is Leakage testing important? Name 2 ways that it can it be performed? 75 © 2006 JDSU. All rights reserved. JDSU CONFIDENTIAL & PROPRIETARY INFORMATION

Questions § Thank you for your time… § Any Questions? ? ? 76 ©

Questions § Thank you for your time… § Any Questions? ? ? 76 © 2006 JDSU. All rights reserved. JDSU CONFIDENTIAL & PROPRIETARY INFORMATION