The Volpe Firm, Inc., profile picture
Uploaded byThe Volpe Firm, Inc.
PDF, PPTX8,684 views

DOCSIS 3.0 Troubleshooting, SCTE Blacksburg, VA

This document provides an overview and biography of Brady Volpe, an expert in cable networking. It discusses his over 20 years of experience working with cable infrastructure equipment and protocols. The rest of the document focuses on introducing concepts related to DOCSIS 3.0 networking standards, including channel bonding, modulation techniques, and advanced troubleshooting of downstream and upstream issues.

Download as PDF, PPTX
Brady Volpe
2 Who the heck am I? • Over 20 years as a normal cable guy. • Started in RF – C-COR Electronics (now Arris) ▫ Flexnet 700, 800, 900 Series Amplifiers ▫ E700 Series Line Extenders ▫ Lumicor Fiber Tx, Rx and EDFAs • First DOCSIS Protocol Analyzer – Most called it “The Sigtek” • Sunrise Telecom, and JDSU • Currently “The Volpe Firm, Inc.” • Check me out! You all will learn a lot on my blog… ▫ http://volpefirm.com © The Volpe Firm Confidential
3 Agenda • DOCSIS 3.0 Overview • DOCSIS 3.0 terminology • DOCSIS modem registration • Advanced Troubleshooting © The Volpe Firm Confidential
4 Drivers for D3.0 – Other than Verizon & AT&T! All Video on Demand 100 Unicast per Subscriber 90 High Definition Video Megabits per Second 80 on Demand 70 Video Blogs Podcasting 60 Video on Demand 50 Video Mail 40 Online Gaming 30 Digital Photos 20 VoIP Digital Music 10 Web Browsing E-mail © The Volpe Firm Time Confidential
5 DOCSIS 3.0 Overview • DOCSIS 3.0 Specification(s) ▫ DOCSIS 3.0 Interface Specifications (Released December 2006) ▫ Equipment readily available • Downstream data rates of 160 Mbps or higher 256QAM => ~40Mbps ▫ Channel Bonding ▫ 4 or more channels 8 x 256QAM => ~304 Mbps • Upstream data rates of 120 Mbps or higher ▫ Channel Bonding ▫ 4 or more channels 64QAM => ~30Mbps • Internet Protocol version 6 (IPv6) 4 x 64QAM => ~108 Mbps ▫ Current System (IPv4) is limited to 4.3B numbers ▫ IPv6 greatly expands the number of IP addresses  Expands IP address size from 32 bits to 128 bits  IPv6 supports 3.4×1038 addresses; 4923:2A1C:0DB8:04F3:AEB5:96F0:E08C:FFEC  Colon-Hexadecimal Format • 100% backward compatible with DOCSIS 1.0/1.1/2.0 © The Volpe Firm Confidential
6 DOCSIS Comparison Max Downstream Max Upstream DOCSIS Version Throughput Throughput 1.x 42.88 (38) Mbit/s 10.24 (9) Mbit/s 2.0 42.88 (38) Mbit/s 30.72 (27) Mbit/s n x 42.88 (38) Mbit/s n x 30.72 (27) Mbit/s 3.0 8 x 38 = 304 Mbit/s 4 x 27 = 108 Mbit/sec © The Volpe Firm Confidential
7 DOCSIS® 3.0 Assumed Downstream RF Channel Transmission Characteristics Parameter Value Frequency range 108 to 1002 MHz edge to edge RF channel spacing (design bandwidth) 6 MHz Transit delay from head-end to most ≤ 0.800 ms (typically much less) distant customer Carrier-to-noise ratio in a 6 MHz band Not less than 35 dB Carrier-to- CTB, CSO, X-MOD, Ingress Not less than 41 dB Amplitude ripple 3 dB within the design bandwidth Group delay ripple in the spectrum 75 ns within the design bandwidth occupied by the CMTS -10 dBc@ <= 0.5 μsec Micro-reflections bound for dominant -20 dBc@ <= 1.5 μsec echo -30 dBc@ > 1.5 μsec Maximum analog video carrier level at 17 dBmV the CM input © The Volpe Firm Confidential
8 DOCSIS® 3.0 Assumed Upstream RF Channel Transmission Characteristics Parameter Value Frequency range 5 to 85 MHz edge to edge Carrier-to-interference plus ingress ratio Not less than 25 dB Carrier hum modulation Not greater than –23 dBc (7%) Not longer than 10 μsec at a 1 kHz Burst noise average rate for most cases Amplitude ripple 5-42 MHz 0.5 dB/MHz Group delay ripple 5-42 MHz 200 ns/MHz -10 dBc@ <= 0.5 μsec Micro-reflections—single echo -20 dBc@ <= 1.0 μsec -30 dBc@ > 1.0 μsec Seasonal and diurnal reverse gain (loss) Not greater than 14 dB min to max variation © The Volpe Firm Confidential
9 The Bonded Upstream © The Volpe Firm Confidential
10 Power Variance – 6dB Bonded vs. Unbonded DOCSIS 3.0 Cable Modem 1 Channel Transmit Power Levels DOCSIS 3.0 Cable Modem 4 Channel Transmit Power Levels © The Volpe Firm Confidential
11 Measuring Upstream Carrier Amplitudes These carriers will NOT have the same peak amplitude level when measured on a typical spectrum analyzer when they are each hitting the CMTS at “0 dBmV power per channel”. Test CW Signal Amplitude CW 1.6 MHz wide 3.2 MHz wide 6.4 MHz wide 1 Hz wide © The Volpe Firm Confidential
12 Real Life Scenario • Upstream at 37 MHz – 64-QAM, 6.4 MHz BW ▫ Twice as wide and 3 dB lower than other carriers • 24.3% FEC errors, 30.6 dB MER • 25 MHz, 28.2 MHz, 31.4 MHz @ 64-QAM, 3.2 MHz okay • Why? What is the problem, what is the recommended solution without going into the field? • cable upstream 3 equalization-coefficient © The Volpe Firm Confidential
13 © The Volpe Firm Confidential
14 Downstream Terminology • Primary Downstream Channel(s) ▫ Master clock, UCD, MAPs, etc. ▫ CMs Registration + PDU • Non-Primary Capable Channel(s) ▫ PDU only ▫ D3.0 modems • Downstream Service Group (DSG) ▫ DS bonded CHs available to CM • Upstream Channel Descriptor – UCD ▫ MAC message to CMs describing US CH © The Volpe Firm Confidential
15 Upstream Terminology • Upstream Channel ▫ Physical Upstream Channel (DOCSIS RF), or ▫ Logical Upstream Channel (share same RF ch) • Upstream Bonding Group (UBG) ▫ Set of US bonded channels for CM © The Volpe Firm Confidential
16 DOCSIS Communications Model IP Data Backbone All three layers must work for DOCSIS to work Server 1 Server 2 Server 3 CMTS Subscriber Side HFC Network © The Volpe Firm Confidential
17 Cable Modem Registration – DOCSIS 1.x/2.0 ▫ CM registration requires the physical layer for signal transport ▫ DOCSIS and IP protocol layers are necessary to communicate the proper messages for modems to come online ▫ The next slides illustrate the interaction of these layers © The Volpe Firm Confidential
18 DS Freq. Acquisition CMTS cable modem Next Sync Broadcast Frequency Scan DS Frequency (Minimum one per 200 msec) for a QAM signal No Yes No Wait for Sync Yes No UCD Broadcast (every 2 sec) Wait for UCD MAP Broadcast (every 2 ms) Wait for MAP © The Volpe Firm Confidential
19 CM Ranging CMTS cable modem RNG-REQ Initial Ranging Request Sent in Initial Maintenance time Slot Starting at 8 dBmV Using an initial SID = 0 RNG-RSP Ranging Response Contains: • Timing offset • Power offset • Temp SID Wait for Increment by RNG-RSP NO 3 dB YES Adjust Timing Offset and Power Offset © The Volpe Firm Confidential
20 DHCP Overview CMTS cable modem Bandwidth Request MAP Broadcasts Use Temp SID (Service ID) DHCP Reply (Offer) DHCP Discover DHCP offers an IP address DHCP Ack (Response) DHCP Request Contains IP Addr, plus Acks Initial lP Address and additional information requests Default GW, ToD Server, TOD offset, TFTP Server Addr and TFTP Boot Config File Name ToD Response Contains Time of Day per ToD Request RFC 868 (Not NTP) © The Volpe Firm Confidential
21 TFTP & Registration CMTS cable modem TFTP Boot File Transfer TFTP Boot Request DOCSIS config file which contains For ‘Boot File name’ Classifiers for QoS and schedule, Baseline Privacy (BPI), etc. Validate file MD5 Checksum Implement Config Registration Request Send QoS Parameters Registration Response Contains Assigned SID Modem registered Registration Acknowledge Send QoS Parameters © The Volpe Firm Confidential
22 CM Registration Summary ▫ Downstream channel search ▫ Ranging ▫ DHCP ▫ ToD ▫ TFTP ▫ Registration ▫ Optional BPI Encryption ▫ Ranging occurs at least every 30 seconds when online  T3 timeout part of this and typically indicate upstream problems  T4 timeout typically indicate downstream problems © The Volpe Firm Confidential
23 D3.0 Modem Registration Scan for DS Channel MAC Domain Provides Primary Ch ID on Secondary Chs Descriptor (MDD) MAC Domain •MD-DS-SG Obtain TX Params •MD-US-SG Descriptor (MDD) •Ch Parameters: Freq, Modulation, etc. Perform Ranging •Security: EAE •DHCP IPv4/IPv6 or suppressed and in config EAE BPI+ •If no MDD  DOCSIS 2.0 mode! DHCP D3.0 DHCP Options •IPv4 Only (DHCPv4) ToD •IPv6 Only (DHCPv6) •Alternate Provisioning Mode (APM) Optional •DHCPv6 then DHCPv4 TFTP •Dual-stack Provisioning Mode (DPM) •DHCPv6 and DHCPv4 Registration DS Ch Bonding •RCC for downstream channels •TCC to add upstream channels Normal BPI+ US Ch Bonding © The Volpe Firm Confidential
24 © The Volpe Firm Confidential
25 Advanced Field Troubleshooting • Why is DOCSIS 3 Troubleshooting Different? ▫ Multiple Bonded Channels  Downstream  Not that different.  The channels are constant carrier  Multiple downstream channels have been around forever  Upstream  Still most vulnerable portion of plant  The modem is no longer limited to a single upstream transmit path  In some ways this is actually easier with DOCSIS 3.0 © The Volpe Firm Confidential
26 You Likely Know Your Problems • Downstream – Typically not so bad ▫ CTB, CSO, CNR under digital channels ▫ Levels not correct into home (high, low, tilt) ▫ Suck-outs, especially if you have contractors doing disconnects ▫ Cheap modulators & upconverters never save you money ▫ DOCSIS 3.0 headaches - Channel bonding, isolation, legacy • Upstream – Your Achilles heal ▫ Easy: AWGN noise, impulse noise, coherent noise, CPD, Laser clipping ▫ Hard: Group delay, frequency response, micro-reflections ▫ Insane: DOCSIS 3.0 – multiple upstreams – power levels • Theft of Service © The Volpe Firm Confidential
27 Likely Upstream Problems ▫ Four times the US bandwidth (four bonded channels) creates a new dynamic for troubleshooting and monitoring: ▫ 6.4 MHz * 4 = 25.6 MHz (without guard bands) ▫ Increased likelihood for laser clipping ▫ Increased probability for problems with ingress, group delay, micro-reflections, and other linear distortions ▫ Inability to avoid problem frequencies such as Citizens’ Band, Ham, Shortwave, and hop between CPD 6MHz spacing ▫ Where are you going to put your sweep points? © The Volpe Firm Confidential
28 Test Equipment has Advanced! © The Volpe Firm Confidential
29 Latest D3.0 Test Meters © The Volpe Firm Confidential
30 Headend Dashboards © The Volpe Firm Confidential
31 Downstream Impairments © The Volpe Firm Confidential
32 Downstream Impairments Ingress, CW Interference © The Volpe Firm Confidential
33 Modulation Error Ratio (MER) – The quality of a QAM signal can be defined by Q the dispersion of the constellation’s points considering the target value I – The error or dispersion power is calculated by the value mean square of the error vectors (real value VS target value) 256 QAM • MER is the ratio in dB between the average   power of the signal and the power of the error   vectors   MER symb dB   10  log10  E av N  1  2 N ej  © The Volpe Firm Confidential  j 1  33
34 MER © The Volpe Firm Confidential
35 Upstream Ingress Cancellation – On default CW Only 10 dB down © The Volpe Firm Confidential
36 Something New – DOCSIS 3.0 Modems © The Volpe Firm Confidential
37 Demod without Cancellation © The Volpe Firm Confidential
38 Testing DOCSIS 3.0 Meter – JDSU DSAM © The Volpe Firm Confidential
39 DOCSIS 3.0 Channel Bonding • Eight channel downstream Bonded Downstream, Eight 256-QAM Carriers
40 VeEX CX380 CM Screen Shot • D3 8x4 Channel Bonding: Details Confidential & Proprietary Information of VeEX Inc
41 A Clean Upstream: Or Is It for 64-QAM? © The Volpe Firm Confidential
42 Impact to Adaptive EQ from Impulse Noise © The Volpe Firm Confidential
43 Ways to Mitigate Impact of Impulse Noise • Clean up plant • Improve robustness of modulation profile from: • cable modulation-profile 224 a-short 6 76 6 22 64qam scrambler 152 no-diff 64 shortened qpsk1 1 2048 • cable modulation-profile 224 a-long 9 232 0 22 64qam scrambler 152 no-diff 64 shortened qpsk1 1 2048 • To: • cable modulation-profile 224 a-short 6 76 6 22 64qam scrambler 152 no-diff 384 shortened qpsk1 0 2048 • cable modulation-profile 224 a-long 9 232 0 22 64qam scrambler 152 no-diff 384 shortened qpsk1 0 2048 • Changing 64 to 384 increases the preamble length, thus enhancing the training sequence on capturing the packet and lessening the effects of impulse noise • Changing the 1 to a 0 enables dynamic interleaving mode, increasing the effectiveness of Forward Error Correction (FEC) as impulse noise increases in the system © The Volpe Firm Confidential
44 Ways to Mitigate Impact of Impulse Noise • Clean up plant • Improve robustness of modulation profile from: • cable modulation-profile 224 initial 5 34 0 48 16qam scrambler 152 no-diff 64 fixed qpsk1 1 2048 • cable modulation-profile 224 station 5 34 0 48 16qam scrambler 152 no-diff 64 fixed qpsk1 1 2048 • To: • cable modulation-profile 224 initial 5 34 0 48 16qam scrambler 152 no-diff 384 fixed qpsk1 0 2048 • cable modulation-profile 224 station 5 34 0 48 16qam scrambler 152 no-diff 384 fixed qpsk1 0 2048 • Changing 64 to 384 increases the preamble length, thus enhancing the training sequence on capturing the packet and lessening the effects of impulse noise • Changing the 1 to a 0 enables dynamic interleaving mode, increasing the effectiveness of Forward Error Correction (FEC) as impulse noise increases in the system © The Volpe Firm Confidential
45 Monitoring Transient Events? • Laser Clipping or Impulse Noise for example… ▫ Plan on laser clipping being a popular word © The Volpe Firm Confidential
46 Two 64-QAM Bonded Channels © The Volpe Firm Confidential
47 Laser Clipping – FP Laser © The Volpe Firm Confidential
48 Laser Clipping – Hard to See © The Volpe Firm Confidential
49 Ingress Under QAM © The Volpe Firm Confidential
50 Laser Heterodyning © The Volpe Firm Confidential
51 Digital Return – RF above 42 MHz © The Volpe Firm Confidential
52 Partial Service Troubleshooting • Partial Service exhibits itself as missing channels • Does not exhibit as Packetloss or Throughput issue © The Volpe Firm Confidential
53 Impaired Service Troubleshooting ▫ An impaired service may or may not exhibit codeword errors and packetloss ▫ When troubleshooting impaired service, it is critical to view the performance of the individual upstream channels. © The Volpe Firm Confidential
54 Impaired Service Troubleshooting © The Volpe Firm Confidential
55 Impaired Service Troubleshooting © The Volpe Firm Confidential
56 Impaired Service Troubleshooting © The Volpe Firm Confidential
57 Impaired Service Troubleshooting © The Volpe Firm Confidential
58 Impaired Service Troubleshooting • Obviously there is an issue with the channel at 19 MHz • Utilize this method to traverse the network and find the impairment causing this issue © The Volpe Firm Confidential
59 Summary • CMTS and SNMP data provide good troubleshooting ▫ But not all of it • DOCSIS 3.0 ▫ Significantly more throughput ▫ Supports legacy D2.0 modems ▫ D3.0 modems load balance in the upstream w/o loss of service • Advanced test equipment is an investment that ▫ Saves you time and money ▫ Gets your subscribers back online and keeps them there ▫ Makes you a predictable and reliable service provider ▫ Seamlessly integrates headend & field – 2 places / 1 person © The Volpe Firm Confidential
60 © The Volpe Firm Confidential
61 IPv6 You may not even know it happened…IPv6 Day June 8th, 2011 © The Volpe Firm Confidential
62 IPv6 and DOCSIS 3.0 • IPv4 only (DHCP4) • IPv6 only (DHCP6) • Alternate Provisioning Mode ▫ DHCP6 then DHCP4 • Dual-Stack Provisioning Mode ▫ DHCP6 and DHCP4 © The Volpe Firm Confidential
Customer admin domain MSO admin domain © The Volpe Firm Access model 1 Confidential Servers • DHCP, DNS CM1 • TFTP CPE1 • TOD bridge • Management Access model 2 To HOME / CORE HFC SMB CPE CM2 Internet CPE2 router CMTS bridge router Access model 3 HOME / SMB CM CPE3 router DOCSIS 3.0 IPv6 Example Architecture Management prefix: 2001:DB8:FFFF:0::/64 Service prefix: 2001:DB8:FFFE:0::/64 Customer 2 prefix: 2001:DB8:2::/48 Customer 3 prefix: 2001:DB8:3::/48 MSO management; assigned 2001:DB8:FFFF:0::/64 MSO service 2001:DB8:FFFE:0::/64 Customer 2 premises link; assigned 2001:DB8:2:0::/64 Customer 3 premises link; assigned 2001:DB8:3:0::/64 63
64 © The Volpe Firm Confidential
65 Why better DOCSIS security? • Various anonymous cable modem hackers have reported high success rates with zero signs of detection ▫ Durandal has a machine on a business configuration that has been seeding torrents steadily for over a year ▫ Many people have as many as 8 or more modems running concurrently ▫ In all of these scenarios, the individuals are paying for service. They are simply splicing their line to add additional modems Its beyond simple theft of service. Substantial traffic users can have a significant impact on system performance Source: Defcon.org © The Volpe Firm Confidential
66 Hacking the Cable Modem • Which OIDs are used for hacking? • 1.3.6.1.2.1.69.1.4.5.0 ▫ To figure out what the current cfg file name is for cable modem. • 1.3.6.1.2.1.10.127.1.1.3.1.3.1 • 1.3.6.1.2.1.10.127.1.1.3.1.5.1 ▫ To check Up/DownStream speed of cfg file • 1.3.6.1.2.1.69.1.4.4.0 ▫ To read TFTP Server IP of cable modem • 1.3.6.1.2.1.69.1.1.3.0 ▫ To reboot cable modem With some software and cheap hardware – hacking is pretty darn simple in a non-BPI+ environment © The Volpe Firm Confidential
67 BPI/BPI+ in DOCSIS 1.x / 2.0 • BPI: Baseline Privacy Interface ▫ Methods for encrypting traffic between the cable modem and the ▫ CMTS with 56bit DES encryption • BPI+: Baseline Privacy Interface Plus ▫ Implemented in DOCSIS 1.1 specs (Backwards compatible) ▫ Introduces X.509 v3 (RSA 1024bit) digital certificates & key pairs ▫ Authentication based on certificate hardware identity; validated when modem registers with a CMTS • Makes hacking a bit more difficult, however… ▫ Operators tend to leave “Self-signed certificates on ▫ During registration, there is no BPI+ security, all transactions are in the clear ▫ DOCSIS 1.x and 2.0 is still exposed to security breaches ▫ Even with Enforce TFTP, Masking TFTP file names, TFTP Proxy, etc. © The Volpe Firm Confidential
68 Enhance DOCSIS 3.0 & IPv6 Security • DOCSIS 3.0 Introduces ▫ 128 bit AES traffic encryption ▫ Early CM authentication and traffic encryption (EAE) ▫ Source IP address verification (SAV) ▫ TFTP proxy and configuration file learning ▫ MMH algorithm for CMTS MIC ▫ Certificate revocation ▫ Encryption support of new method of multicast messaging © The Volpe Firm Confidential
69 Security Recommendation • Enable BPI+ and EAE • Use BPI+ Enforce • Disable Self-Signed Certificates • Use “Secure Provisioning” by leveraging SAV • Only allow CM software download via CVC • Disable Public SNMP access • Eliminate “Walled Garden” customer access points ▫ Walled Garden sites are the primary gateway for theft-of- service • Restrict access of your security department and policies to a limited, trusted number of people ▫ Security breeches often come from within © The Volpe Firm Confidential
70 For more information go to: http://volpefirm.com © The Volpe Firm Confidential

More Related Content

PPTX
Advanced Troubleshooting in a DOCSIS 3.0 Plant
byThe Volpe Firm, Inc.
 
PPTX
IBS TRAINING（new）.pptx
byHussienEndris1
 
PDF
GPON-FTTx Training
byAzhar Khuwaja
 
PPTX
Fttx ftth cabling system
bySun Telecommunication (Shanghai) Co., Ltd.
 
PDF
Understanding olt, onu, ont and odn full
byS M Tipu
 
PPT
Passive Optical Networks
byfanttazio
 
PDF
FTTH Basics
byAnuradha Udunuwara
 
PPTX
Bsnl
byRanjan Gupta
 
Advanced Troubleshooting in a DOCSIS 3.0 Plant
byThe Volpe Firm, Inc.
 
IBS TRAINING（new）.pptx
byHussienEndris1
 
GPON-FTTx Training
byAzhar Khuwaja
 
Fttx ftth cabling system
bySun Telecommunication (Shanghai) Co., Ltd.
 
Understanding olt, onu, ont and odn full
byS M Tipu
 
Passive Optical Networks
byfanttazio
 
FTTH Basics
byAnuradha Udunuwara
 
Bsnl
byRanjan Gupta
 

What's hot

PDF
FTTH Basics and Network Design.pdf
byHisham Hasan
 
PDF
FTTX Basics and Network Design
byOFS
 
PPTX
FTTx Basics & Its Network Basics
byमहेंद्र Mahendra लाठी Lathi
 
PDF
FTTx - GPON technology.pdf
bybinhzte
 
PPT
Induccion Tecnologia HFC Basico
bymarlon0984
 
PDF
Passive Optical Networks - PON: Customer Case Study, Design, Implementation a...
byBruno Teixeira
 
PPT
Gpon fundamentals
byPablo Guillen
 
PPT
Fttx
byUnnikrishnan Nair
 
PPT
FTTH
byGopakumar Panicker
 
PDF
Passive infrastructure of FTTH networks: an overview
byLuc De Heyn
 
PDF
FTTH Network Structure
byKHNOG
 
PPT
FTTH / FTTX optimization, automatic cost optimized network design & engineering
byvan den Dool Dick
 
PPTX
Unit 1 network models & typical examples(part b)
byVishal kakade
 
PPT
Handling Common Faults and Alarms for Huawei RTN Microwaves
byibrahimnabil17
 
PDF
ROADM Technologies for Flexible - Tbitsec Optical Networks
byCPqD
 
PDF
Ceragon
byГруппа компаний СИС
 
PDF
Powerwave 7785.00
bymohammad ali amini
 
PPTX
Passive Optical Network (PON)
byMúşčâp Hãkíìm
 
PPTX
Ericsson TN Cards in Details
byibrahimnabil17
 
PDF
loss budget calculation in fiber optic link
byJOHNSON ADEJOLA ( Msc, CCNA,CFOT, CFOS/D/H/I/O/L
 
FTTH Basics and Network Design.pdf
byHisham Hasan
 
FTTX Basics and Network Design
byOFS
 
FTTx Basics & Its Network Basics
byमहेंद्र Mahendra लाठी Lathi
 
FTTx - GPON technology.pdf
bybinhzte
 
Induccion Tecnologia HFC Basico
bymarlon0984
 
Passive Optical Networks - PON: Customer Case Study, Design, Implementation a...
byBruno Teixeira
 
Gpon fundamentals
byPablo Guillen
 
Fttx
byUnnikrishnan Nair
 
FTTH
byGopakumar Panicker
 
Passive infrastructure of FTTH networks: an overview
byLuc De Heyn
 
FTTH Network Structure
byKHNOG
 
FTTH / FTTX optimization, automatic cost optimized network design & engineering
byvan den Dool Dick
 
Unit 1 network models & typical examples(part b)
byVishal kakade
 
Handling Common Faults and Alarms for Huawei RTN Microwaves
byibrahimnabil17
 
ROADM Technologies for Flexible - Tbitsec Optical Networks
byCPqD
 
Ceragon
byГруппа компаний СИС
 
Powerwave 7785.00
bymohammad ali amini
 
Passive Optical Network (PON)
byMúşčâp Hãkíìm
 
Ericsson TN Cards in Details
byibrahimnabil17
 
loss budget calculation in fiber optic link
byJOHNSON ADEJOLA ( Msc, CCNA,CFOT, CFOS/D/H/I/O/L
 

Viewers also liked

PPTX
DOCSIS 3.0 SCTE Piedmont Chapter January 18th
byThe Volpe Firm, Inc.
 
PPT
Docsis overview
byAnderson Huang
 
PDF
A very quick introduction to HFC, DOCSIS 3.0 and 3.1
byErik Vloothuis
 
PDF
DOCSIS CMTS Suggestions, Best Practices and Recommendations
byThe Volpe Firm, Inc.
 
PDF
ITU-T Study Group 15 Introduction
byITU
 
PDF
Remote PHY for Converged DOCSIS, Video and OOB
byCisco Service Provider
 
PPT
Szerokopasmowe (stacjonarne) sieci dostępowe
bybartekel
 
PPTX
44 - IDNOG03 - LT - Rommy Kuntoro - G.Fast 1Gbps over Copper Cable, Are we r...
byIndonesia Network Operators Group
 
PDF
Docsis 20 getting to know
byherooftit
 
PPTX
Clive Selley - CEO Openreach
byIndependent Networks Co-operative Association
 
PPTX
Tecom Portfolio
bysuresh ranga
 
PPTX
Smau Milano 2016 - Newen
bySMAU
 
PDF
Data over Coax - The Best Last Mile Access Technology before FTTH
byTeleste Corporation
 
PDF
DOCSIS DS & US Speed Playbook as presented in G+HOA
byThe Volpe Firm, Inc.
 
PPTX
Ruth Colvin Clark
bybeebsy
 
PDF
DWS16 - Future networks forum - Luis Alveirinho, Portugal Telecom
byIDATE DigiWorld
 
PDF
Assises THD 2016 - Vers un marché unique du THD - Dominique Meunier IDATE Dig...
byIDATE DigiWorld
 
PDF
February 2016-calix-investor-presentation
byCalixInc
 
PDF
DWS16 - Future networks forum - Alexis Argoud French Digital Agency
byIDATE DigiWorld
 
PPTX
Open Access – rewolucja w dostępie? prof. Marek Niezgódka, ICM UW
byPlatforma Otwartej Nauki
 
DOCSIS 3.0 SCTE Piedmont Chapter January 18th
byThe Volpe Firm, Inc.
 
Docsis overview
byAnderson Huang
 
A very quick introduction to HFC, DOCSIS 3.0 and 3.1
byErik Vloothuis
 
DOCSIS CMTS Suggestions, Best Practices and Recommendations
byThe Volpe Firm, Inc.
 
ITU-T Study Group 15 Introduction
byITU
 
Remote PHY for Converged DOCSIS, Video and OOB
byCisco Service Provider
 
Szerokopasmowe (stacjonarne) sieci dostępowe
bybartekel
 
44 - IDNOG03 - LT - Rommy Kuntoro - G.Fast 1Gbps over Copper Cable, Are we r...
byIndonesia Network Operators Group
 
Docsis 20 getting to know
byherooftit
 
Clive Selley - CEO Openreach
byIndependent Networks Co-operative Association
 
Tecom Portfolio
bysuresh ranga
 
Smau Milano 2016 - Newen
bySMAU
 
Data over Coax - The Best Last Mile Access Technology before FTTH
byTeleste Corporation
 
DOCSIS DS & US Speed Playbook as presented in G+HOA
byThe Volpe Firm, Inc.
 
Ruth Colvin Clark
bybeebsy
 
DWS16 - Future networks forum - Luis Alveirinho, Portugal Telecom
byIDATE DigiWorld
 
Assises THD 2016 - Vers un marché unique du THD - Dominique Meunier IDATE Dig...
byIDATE DigiWorld
 
February 2016-calix-investor-presentation
byCalixInc
 
DWS16 - Future networks forum - Alexis Argoud French Digital Agency
byIDATE DigiWorld
 
Open Access – rewolucja w dostępie? prof. Marek Niezgódka, ICM UW
byPlatforma Otwartej Nauki
 

Similar to DOCSIS 3.0 Troubleshooting, SCTE Blacksburg, VA

PDF
MPLS in Mobile Backhaul
byScott Foster
 
PDF
The Outlook of Broad Band Optical Access Networks
byCedric Lam
 
PDF
Managing the Mobile Device Wave for Enterpise Wireless Networks: Best Practices
byCisco Mobility
 
PDF
Polycom Competitive Q1 08
byVideoguy
 
PDF
Cisco Video Data Explosion
bymenkento
 
PDF
Tranzeo EL-900 Outdoor AP/ Router/ Bridge (quantumwimax.com)
byAri Zoldan
 
PDF
Enabling the Borderless Organization
byCisco Canada
 
PDF
Comparação Grandstream
bySmartSolutionsTeleccom
 
PDF
Are ott the new walled gardens
byAmir Zmora
 
PDF
10 fn tut2
byScott Foster
 
PDF
Hdx7000 Series
byguest6f1642
 
PDF
Sip 03
byCCSMOUNTCAMERA
 
PDF
Lte Latin America 2011 Ims Assuming An Important Role On Lte V1.0
byAlberto Boaventura
 
PPTX
Developments in Managed Content Distribution
byCisco Service Provider
 
PDF
Surf Solutions intro to new partner jan2011
byRudy Shainer
 
PPTX
The Network After SONET
byCisco Service Provider
 
PPT
Soluciones de Colaboración 2011
byLogicalis Latam
 
PPT
Roadshow Colaboración 2011 Uruguay
byLogicalis Latam
 
PDF
Монетизания: Достижение прибыльности мобильного Интернета нового поколения.
byCisco Russia
 
PDF
Klimenok telepresence
bymoldovaictsummit
 
MPLS in Mobile Backhaul
byScott Foster
 
The Outlook of Broad Band Optical Access Networks
byCedric Lam
 
Managing the Mobile Device Wave for Enterpise Wireless Networks: Best Practices
byCisco Mobility
 
Polycom Competitive Q1 08
byVideoguy
 
Cisco Video Data Explosion
bymenkento
 
Tranzeo EL-900 Outdoor AP/ Router/ Bridge (quantumwimax.com)
byAri Zoldan
 
Enabling the Borderless Organization
byCisco Canada
 
Comparação Grandstream
bySmartSolutionsTeleccom
 
Are ott the new walled gardens
byAmir Zmora
 
10 fn tut2
byScott Foster
 
Hdx7000 Series
byguest6f1642
 
Sip 03
byCCSMOUNTCAMERA
 
Lte Latin America 2011 Ims Assuming An Important Role On Lte V1.0
byAlberto Boaventura
 
Developments in Managed Content Distribution
byCisco Service Provider
 
Surf Solutions intro to new partner jan2011
byRudy Shainer
 
The Network After SONET
byCisco Service Provider
 
Soluciones de Colaboración 2011
byLogicalis Latam
 
Roadshow Colaboración 2011 Uruguay
byLogicalis Latam
 
Монетизания: Достижение прибыльности мобильного Интернета нового поколения.
byCisco Russia
 
Klimenok telepresence
bymoldovaictsummit
 

More from The Volpe Firm, Inc.

PDF
Anga 2013 v2
byThe Volpe Firm, Inc.
 
PDF
Alignment in DDA Distributed Access Architecture_4-28-2020
byThe Volpe Firm, Inc.
 
PDF
Remote phy: podcast or hangout episode 28
byThe Volpe Firm, Inc.
 
PDF
DOCSIS CMTS best practices and recommendations part 3
byThe Volpe Firm, Inc.
 
PPTX
The volpe firm 11.1.13
byThe Volpe Firm, Inc.
 
PPTX
Water soaked cable 1.3
byThe Volpe Firm, Inc.
 
Anga 2013 v2
byThe Volpe Firm, Inc.
 
Alignment in DDA Distributed Access Architecture_4-28-2020
byThe Volpe Firm, Inc.
 
Remote phy: podcast or hangout episode 28
byThe Volpe Firm, Inc.
 
DOCSIS CMTS best practices and recommendations part 3
byThe Volpe Firm, Inc.
 
The volpe firm 11.1.13
byThe Volpe Firm, Inc.
 
Water soaked cable 1.3
byThe Volpe Firm, Inc.
 

Recently uploaded

PDF
From Pixels to Insights: Getting Started with Imagery in FME
bySafe Software
 
PDF
Supercharge Your JVM with Project Leyden
byAna-Maria Mihalceanu
 
PDF
WebXR in Android and Linux with OpenXR
byIgalia
 
PPTX
Building Smarter Integrations with MuleSoft_ MCP Server and Cursor in Action ...
byKunal Gupta
 
PDF
The Future-Ready PMO: Unlocking Project Success with Copilot and AI Innovatio...
byWellingtone
 
PDF
Data Center Exit to Cloud _ Managed Datacenter Migration.pdf
byAstuteBusiness
 
PDF
PDF Security Intelligence Platform | Cybersecurity Project by Ashish Patil
byAshishPatil495087
 
PPTX
Sephora UAE API Service Real-Time Product & Price Data Access.pptx
bycreativeclicks1733
 
PDF
Unlocking Access: Enriching Public Services with Location Intelligence.pdf
byPrecisely
 
PDF
Wrapping up unowned UTF8 C strings: CStringView
byIgalia
 
PDF
MathML Core in WebKit
byIgalia
 
PDF
How Generative AI Helps US Healthcare Startups Save 40.pdf
byimoliviabennett
 
PDF
OpenObserve as a replacement for Elasticsearch
byAlireza Kamrani
 
PDF
PromptShelf.ai Is Live: Discover, Create, and Manage AI Prompts That Actually...
byTalavera Solutions
 
PDF
The new commer in Oracle memory architecture _Database Box).pdf
byAlireza Kamrani
 
PPTX
GenAI GraphTalk - Kuala Lumpur - 4 Nov 2025
bygourisachdeva2
 
PPSX
AppSec Role Based Training OWASP Global AppSec USA 2025-11-06
byRobert Grupe, CSSLP CISSP PE PMP
 
PDF
Manage Local Users and Groups - RHCSA (RH124)
byLinuxCert Guru
 
PDF
Access Linux File System in RHEL - RHCSA (RH124).pdf
byLinuxCert Guru
 
PDF
Writing GPU-Ready AI Models in Pure Java with Babylon
byAna-Maria Mihalceanu
 
From Pixels to Insights: Getting Started with Imagery in FME
bySafe Software
 
Supercharge Your JVM with Project Leyden
byAna-Maria Mihalceanu
 
WebXR in Android and Linux with OpenXR
byIgalia
 
Building Smarter Integrations with MuleSoft_ MCP Server and Cursor in Action ...
byKunal Gupta
 
The Future-Ready PMO: Unlocking Project Success with Copilot and AI Innovatio...
byWellingtone
 
Data Center Exit to Cloud _ Managed Datacenter Migration.pdf
byAstuteBusiness
 
PDF Security Intelligence Platform | Cybersecurity Project by Ashish Patil
byAshishPatil495087
 
Sephora UAE API Service Real-Time Product & Price Data Access.pptx
bycreativeclicks1733
 
Unlocking Access: Enriching Public Services with Location Intelligence.pdf
byPrecisely
 
Wrapping up unowned UTF8 C strings: CStringView
byIgalia
 
MathML Core in WebKit
byIgalia
 
How Generative AI Helps US Healthcare Startups Save 40.pdf
byimoliviabennett
 
OpenObserve as a replacement for Elasticsearch
byAlireza Kamrani
 
PromptShelf.ai Is Live: Discover, Create, and Manage AI Prompts That Actually...
byTalavera Solutions
 
The new commer in Oracle memory architecture _Database Box).pdf
byAlireza Kamrani
 
GenAI GraphTalk - Kuala Lumpur - 4 Nov 2025
bygourisachdeva2
 
AppSec Role Based Training OWASP Global AppSec USA 2025-11-06
byRobert Grupe, CSSLP CISSP PE PMP
 
Manage Local Users and Groups - RHCSA (RH124)
byLinuxCert Guru
 
Access Linux File System in RHEL - RHCSA (RH124).pdf
byLinuxCert Guru
 
Writing GPU-Ready AI Models in Pure Java with Babylon
byAna-Maria Mihalceanu
 

DOCSIS 3.0 Troubleshooting, SCTE Blacksburg, VA

  • 1.
  • 2.
    2 Who the heckam I? • Over 20 years as a normal cable guy. • Started in RF – C-COR Electronics (now Arris) ▫ Flexnet 700, 800, 900 Series Amplifiers ▫ E700 Series Line Extenders ▫ Lumicor Fiber Tx, Rx and EDFAs • First DOCSIS Protocol Analyzer – Most called it “The Sigtek” • Sunrise Telecom, and JDSU • Currently “The Volpe Firm, Inc.” • Check me out! You all will learn a lot on my blog… ▫ http://volpefirm.com © The Volpe Firm Confidential
  • 3.
    3 Agenda • DOCSIS 3.0 Overview • DOCSIS 3.0 terminology • DOCSIS modem registration • Advanced Troubleshooting © The Volpe Firm Confidential
  • 4.
    4 Drivers forD3.0 – Other than Verizon & AT&T! All Video on Demand 100 Unicast per Subscriber 90 High Definition Video Megabits per Second 80 on Demand 70 Video Blogs Podcasting 60 Video on Demand 50 Video Mail 40 Online Gaming 30 Digital Photos 20 VoIP Digital Music 10 Web Browsing E-mail © The Volpe Firm Time Confidential
  • 5.
    5 DOCSIS 3.0 Overview •DOCSIS 3.0 Specification(s) ▫ DOCSIS 3.0 Interface Specifications (Released December 2006) ▫ Equipment readily available • Downstream data rates of 160 Mbps or higher 256QAM => ~40Mbps ▫ Channel Bonding ▫ 4 or more channels 8 x 256QAM => ~304 Mbps • Upstream data rates of 120 Mbps or higher ▫ Channel Bonding ▫ 4 or more channels 64QAM => ~30Mbps • Internet Protocol version 6 (IPv6) 4 x 64QAM => ~108 Mbps ▫ Current System (IPv4) is limited to 4.3B numbers ▫ IPv6 greatly expands the number of IP addresses  Expands IP address size from 32 bits to 128 bits  IPv6 supports 3.4×1038 addresses; 4923:2A1C:0DB8:04F3:AEB5:96F0:E08C:FFEC  Colon-Hexadecimal Format • 100% backward compatible with DOCSIS 1.0/1.1/2.0 © The Volpe Firm Confidential
  • 6.
    6 DOCSIS Comparison Max Downstream Max Upstream DOCSIS Version Throughput Throughput 1.x 42.88 (38) Mbit/s 10.24 (9) Mbit/s 2.0 42.88 (38) Mbit/s 30.72 (27) Mbit/s n x 42.88 (38) Mbit/s n x 30.72 (27) Mbit/s 3.0 8 x 38 = 304 Mbit/s 4 x 27 = 108 Mbit/sec © The Volpe Firm Confidential
  • 7.
    7 DOCSIS® 3.0 AssumedDownstream RF Channel Transmission Characteristics Parameter Value Frequency range 108 to 1002 MHz edge to edge RF channel spacing (design bandwidth) 6 MHz Transit delay from head-end to most ≤ 0.800 ms (typically much less) distant customer Carrier-to-noise ratio in a 6 MHz band Not less than 35 dB Carrier-to- CTB, CSO, X-MOD, Ingress Not less than 41 dB Amplitude ripple 3 dB within the design bandwidth Group delay ripple in the spectrum 75 ns within the design bandwidth occupied by the CMTS -10 dBc@ <= 0.5 μsec Micro-reflections bound for dominant -20 dBc@ <= 1.5 μsec echo -30 dBc@ > 1.5 μsec Maximum analog video carrier level at 17 dBmV the CM input © The Volpe Firm Confidential
  • 8.
    8 DOCSIS® 3.0 AssumedUpstream RF Channel Transmission Characteristics Parameter Value Frequency range 5 to 85 MHz edge to edge Carrier-to-interference plus ingress ratio Not less than 25 dB Carrier hum modulation Not greater than –23 dBc (7%) Not longer than 10 μsec at a 1 kHz Burst noise average rate for most cases Amplitude ripple 5-42 MHz 0.5 dB/MHz Group delay ripple 5-42 MHz 200 ns/MHz -10 dBc@ <= 0.5 μsec Micro-reflections—single echo -20 dBc@ <= 1.0 μsec -30 dBc@ > 1.0 μsec Seasonal and diurnal reverse gain (loss) Not greater than 14 dB min to max variation © The Volpe Firm Confidential
  • 9.
    9 The Bonded Upstream © The Volpe Firm Confidential
  • 10.
    10 Power Variance –6dB Bonded vs. Unbonded DOCSIS 3.0 Cable Modem 1 Channel Transmit Power Levels DOCSIS 3.0 Cable Modem 4 Channel Transmit Power Levels © The Volpe Firm Confidential
  • 11.
    11 Measuring Upstream CarrierAmplitudes These carriers will NOT have the same peak amplitude level when measured on a typical spectrum analyzer when they are each hitting the CMTS at “0 dBmV power per channel”. Test CW Signal Amplitude CW 1.6 MHz wide 3.2 MHz wide 6.4 MHz wide 1 Hz wide © The Volpe Firm Confidential
  • 12.
    12 RealLife Scenario • Upstream at 37 MHz – 64-QAM, 6.4 MHz BW ▫ Twice as wide and 3 dB lower than other carriers • 24.3% FEC errors, 30.6 dB MER • 25 MHz, 28.2 MHz, 31.4 MHz @ 64-QAM, 3.2 MHz okay • Why? What is the problem, what is the recommended solution without going into the field? • cable upstream 3 equalization-coefficient © The Volpe Firm Confidential
  • 13.
    13 © The VolpeFirm Confidential
  • 14.
    14 Downstream Terminology • PrimaryDownstream Channel(s) ▫ Master clock, UCD, MAPs, etc. ▫ CMs Registration + PDU • Non-Primary Capable Channel(s) ▫ PDU only ▫ D3.0 modems • Downstream Service Group (DSG) ▫ DS bonded CHs available to CM • Upstream Channel Descriptor – UCD ▫ MAC message to CMs describing US CH © The Volpe Firm Confidential
  • 15.
    15 Upstream Terminology • UpstreamChannel ▫ Physical Upstream Channel (DOCSIS RF), or ▫ Logical Upstream Channel (share same RF ch) • Upstream Bonding Group (UBG) ▫ Set of US bonded channels for CM © The Volpe Firm Confidential
  • 16.
    16 DOCSIS Communications Model IP Data Backbone All three layers must work for DOCSIS to work Server 1 Server 2 Server 3 CMTS Subscriber Side HFC Network © The Volpe Firm Confidential
  • 17.
    17 Cable Modem Registration – DOCSIS 1.x/2.0 ▫ CM registration requires the physical layer for signal transport ▫ DOCSIS and IP protocol layers are necessary to communicate the proper messages for modems to come online ▫ The next slides illustrate the interaction of these layers © The Volpe Firm Confidential
  • 18.
    18 DSFreq. Acquisition CMTS cable modem Next Sync Broadcast Frequency Scan DS Frequency (Minimum one per 200 msec) for a QAM signal No Yes No Wait for Sync Yes No UCD Broadcast (every 2 sec) Wait for UCD MAP Broadcast (every 2 ms) Wait for MAP © The Volpe Firm Confidential
  • 19.
    19 CM Ranging CMTS cable modem RNG-REQ Initial Ranging Request Sent in Initial Maintenance time Slot Starting at 8 dBmV Using an initial SID = 0 RNG-RSP Ranging Response Contains: • Timing offset • Power offset • Temp SID Wait for Increment by RNG-RSP NO 3 dB YES Adjust Timing Offset and Power Offset © The Volpe Firm Confidential
  • 20.
    20 DHCP Overview CMTS cable modem Bandwidth Request MAP Broadcasts Use Temp SID (Service ID) DHCP Reply (Offer) DHCP Discover DHCP offers an IP address DHCP Ack (Response) DHCP Request Contains IP Addr, plus Acks Initial lP Address and additional information requests Default GW, ToD Server, TOD offset, TFTP Server Addr and TFTP Boot Config File Name ToD Response Contains Time of Day per ToD Request RFC 868 (Not NTP) © The Volpe Firm Confidential
  • 21.
    21 TFTP & Registration CMTS cable modem TFTP Boot File Transfer TFTP Boot Request DOCSIS config file which contains For ‘Boot File name’ Classifiers for QoS and schedule, Baseline Privacy (BPI), etc. Validate file MD5 Checksum Implement Config Registration Request Send QoS Parameters Registration Response Contains Assigned SID Modem registered Registration Acknowledge Send QoS Parameters © The Volpe Firm Confidential
  • 22.
    22 CM Registration Summary ▫ Downstream channel search ▫ Ranging ▫ DHCP ▫ ToD ▫ TFTP ▫ Registration ▫ Optional BPI Encryption ▫ Ranging occurs at least every 30 seconds when online  T3 timeout part of this and typically indicate upstream problems  T4 timeout typically indicate downstream problems © The Volpe Firm Confidential
  • 23.
    23 D3.0 Modem Registration Scan for DS Channel MAC Domain Provides Primary Ch ID on Secondary Chs Descriptor (MDD) MAC Domain •MD-DS-SG Obtain TX Params •MD-US-SG Descriptor (MDD) •Ch Parameters: Freq, Modulation, etc. Perform Ranging •Security: EAE •DHCP IPv4/IPv6 or suppressed and in config EAE BPI+ •If no MDD  DOCSIS 2.0 mode! DHCP D3.0 DHCP Options •IPv4 Only (DHCPv4) ToD •IPv6 Only (DHCPv6) •Alternate Provisioning Mode (APM) Optional •DHCPv6 then DHCPv4 TFTP •Dual-stack Provisioning Mode (DPM) •DHCPv6 and DHCPv4 Registration DS Ch Bonding •RCC for downstream channels •TCC to add upstream channels Normal BPI+ US Ch Bonding © The Volpe Firm Confidential
  • 24.
    24 © The VolpeFirm Confidential
  • 25.
    25 Advanced Field Troubleshooting •Why is DOCSIS 3 Troubleshooting Different? ▫ Multiple Bonded Channels  Downstream  Not that different.  The channels are constant carrier  Multiple downstream channels have been around forever  Upstream  Still most vulnerable portion of plant  The modem is no longer limited to a single upstream transmit path  In some ways this is actually easier with DOCSIS 3.0 © The Volpe Firm Confidential
  • 26.
    26 You Likely KnowYour Problems • Downstream – Typically not so bad ▫ CTB, CSO, CNR under digital channels ▫ Levels not correct into home (high, low, tilt) ▫ Suck-outs, especially if you have contractors doing disconnects ▫ Cheap modulators & upconverters never save you money ▫ DOCSIS 3.0 headaches - Channel bonding, isolation, legacy • Upstream – Your Achilles heal ▫ Easy: AWGN noise, impulse noise, coherent noise, CPD, Laser clipping ▫ Hard: Group delay, frequency response, micro-reflections ▫ Insane: DOCSIS 3.0 – multiple upstreams – power levels • Theft of Service © The Volpe Firm Confidential
  • 27.
    27 Likely Upstream Problems ▫ Four times the US bandwidth (four bonded channels) creates a new dynamic for troubleshooting and monitoring: ▫ 6.4 MHz * 4 = 25.6 MHz (without guard bands) ▫ Increased likelihood for laser clipping ▫ Increased probability for problems with ingress, group delay, micro-reflections, and other linear distortions ▫ Inability to avoid problem frequencies such as Citizens’ Band, Ham, Shortwave, and hop between CPD 6MHz spacing ▫ Where are you going to put your sweep points? © The Volpe Firm Confidential
  • 28.
    28 Test Equipment hasAdvanced! © The Volpe Firm Confidential
  • 29.
    29 Latest D3.0 TestMeters © The Volpe Firm Confidential
  • 30.
    30 Headend Dashboards © The Volpe Firm Confidential
  • 31.
    31 Downstream Impairments © The Volpe Firm Confidential
  • 32.
    32 Downstream Impairments Ingress, CW Interference © The Volpe Firm Confidential
  • 33.
    33 Modulation Error Ratio(MER) – The quality of a QAM signal can be defined by Q the dispersion of the constellation’s points considering the target value I – The error or dispersion power is calculated by the value mean square of the error vectors (real value VS target value) 256 QAM • MER is the ratio in dB between the average   power of the signal and the power of the error   vectors   MER symb dB   10  log10  E av N  1  2 N ej  © The Volpe Firm Confidential  j 1  33
  • 34.
    34 MER © The Volpe Firm Confidential
  • 35.
    35 Upstream Ingress Cancellation– On default CW Only 10 dB down © The Volpe Firm Confidential
  • 36.
    36 Something New –DOCSIS 3.0 Modems © The Volpe Firm Confidential
  • 37.
    37 Demod without Cancellation © The Volpe Firm Confidential
  • 38.
    38 Testing DOCSIS 3.0Meter – JDSU DSAM © The Volpe Firm Confidential
  • 39.
    39 DOCSIS 3.0 Channel Bonding • Eight channel downstream Bonded Downstream, Eight 256-QAM Carriers
  • 40.
    40 VeEX CX380 CMScreen Shot • D3 8x4 Channel Bonding: Details Confidential & Proprietary Information of VeEX Inc
  • 41.
    41 A Clean Upstream:Or Is It for 64-QAM? © The Volpe Firm Confidential
  • 42.
    42 Impact to AdaptiveEQ from Impulse Noise © The Volpe Firm Confidential
  • 43.
    43 Ways to MitigateImpact of Impulse Noise • Clean up plant • Improve robustness of modulation profile from: • cable modulation-profile 224 a-short 6 76 6 22 64qam scrambler 152 no-diff 64 shortened qpsk1 1 2048 • cable modulation-profile 224 a-long 9 232 0 22 64qam scrambler 152 no-diff 64 shortened qpsk1 1 2048 • To: • cable modulation-profile 224 a-short 6 76 6 22 64qam scrambler 152 no-diff 384 shortened qpsk1 0 2048 • cable modulation-profile 224 a-long 9 232 0 22 64qam scrambler 152 no-diff 384 shortened qpsk1 0 2048 • Changing 64 to 384 increases the preamble length, thus enhancing the training sequence on capturing the packet and lessening the effects of impulse noise • Changing the 1 to a 0 enables dynamic interleaving mode, increasing the effectiveness of Forward Error Correction (FEC) as impulse noise increases in the system © The Volpe Firm Confidential
  • 44.
    44 Ways to MitigateImpact of Impulse Noise • Clean up plant • Improve robustness of modulation profile from: • cable modulation-profile 224 initial 5 34 0 48 16qam scrambler 152 no-diff 64 fixed qpsk1 1 2048 • cable modulation-profile 224 station 5 34 0 48 16qam scrambler 152 no-diff 64 fixed qpsk1 1 2048 • To: • cable modulation-profile 224 initial 5 34 0 48 16qam scrambler 152 no-diff 384 fixed qpsk1 0 2048 • cable modulation-profile 224 station 5 34 0 48 16qam scrambler 152 no-diff 384 fixed qpsk1 0 2048 • Changing 64 to 384 increases the preamble length, thus enhancing the training sequence on capturing the packet and lessening the effects of impulse noise • Changing the 1 to a 0 enables dynamic interleaving mode, increasing the effectiveness of Forward Error Correction (FEC) as impulse noise increases in the system © The Volpe Firm Confidential
  • 45.
    45 Monitoring Transient Events? •Laser Clipping or Impulse Noise for example… ▫ Plan on laser clipping being a popular word © The Volpe Firm Confidential
  • 46.
    46 Two 64-QAM BondedChannels © The Volpe Firm Confidential
  • 47.
    47 Laser Clipping –FP Laser © The Volpe Firm Confidential
  • 48.
    48 Laser Clipping –Hard to See © The Volpe Firm Confidential
  • 49.
    49 Ingress Under QAM © The Volpe Firm Confidential
  • 50.
    50 Laser Heterodyning © The Volpe Firm Confidential
  • 51.
    51 Digital Return –RF above 42 MHz © The Volpe Firm Confidential
  • 52.
    52 Partial Service Troubleshooting •Partial Service exhibits itself as missing channels • Does not exhibit as Packetloss or Throughput issue © The Volpe Firm Confidential
  • 53.
    53 Impaired Service Troubleshooting ▫ An impaired service may or may not exhibit codeword errors and packetloss ▫ When troubleshooting impaired service, it is critical to view the performance of the individual upstream channels. © The Volpe Firm Confidential
  • 54.
    54 Impaired Service Troubleshooting © The Volpe Firm Confidential
  • 55.
    55 Impaired Service Troubleshooting © The Volpe Firm Confidential
  • 56.
    56 Impaired Service Troubleshooting © The Volpe Firm Confidential
  • 57.
    57 Impaired Service Troubleshooting © The Volpe Firm Confidential
  • 58.
    58 Impaired Service Troubleshooting •Obviously there is an issue with the channel at 19 MHz • Utilize this method to traverse the network and find the impairment causing this issue © The Volpe Firm Confidential
  • 59.
    59 Summary •CMTS and SNMP data provide good troubleshooting ▫ But not all of it • DOCSIS 3.0 ▫ Significantly more throughput ▫ Supports legacy D2.0 modems ▫ D3.0 modems load balance in the upstream w/o loss of service • Advanced test equipment is an investment that ▫ Saves you time and money ▫ Gets your subscribers back online and keeps them there ▫ Makes you a predictable and reliable service provider ▫ Seamlessly integrates headend & field – 2 places / 1 person © The Volpe Firm Confidential
  • 60.
    60 © The VolpeFirm Confidential
  • 61.
    61 IPv6 You maynot even know it happened…IPv6 Day June 8th, 2011 © The Volpe Firm Confidential
  • 62.
    62 IPv6and DOCSIS 3.0 • IPv4 only (DHCP4) • IPv6 only (DHCP6) • Alternate Provisioning Mode ▫ DHCP6 then DHCP4 • Dual-Stack Provisioning Mode ▫ DHCP6 and DHCP4 © The Volpe Firm Confidential
  • 63.
    Customer admin domain MSO admin domain © The Volpe Firm Access model 1 Confidential Servers • DHCP, DNS CM1 • TFTP CPE1 • TOD bridge • Management Access model 2 To HOME / CORE HFC SMB CPE CM2 Internet CPE2 router CMTS bridge router Access model 3 HOME / SMB CM CPE3 router DOCSIS 3.0 IPv6 Example Architecture Management prefix: 2001:DB8:FFFF:0::/64 Service prefix: 2001:DB8:FFFE:0::/64 Customer 2 prefix: 2001:DB8:2::/48 Customer 3 prefix: 2001:DB8:3::/48 MSO management; assigned 2001:DB8:FFFF:0::/64 MSO service 2001:DB8:FFFE:0::/64 Customer 2 premises link; assigned 2001:DB8:2:0::/64 Customer 3 premises link; assigned 2001:DB8:3:0::/64 63
  • 64.
    64 © The VolpeFirm Confidential
  • 65.
    65 Why better DOCSIS security? • Various anonymous cable modem hackers have reported high success rates with zero signs of detection ▫ Durandal has a machine on a business configuration that has been seeding torrents steadily for over a year ▫ Many people have as many as 8 or more modems running concurrently ▫ In all of these scenarios, the individuals are paying for service. They are simply splicing their line to add additional modems Its beyond simple theft of service. Substantial traffic users can have a significant impact on system performance Source: Defcon.org © The Volpe Firm Confidential
  • 66.
    66 Hacking the CableModem • Which OIDs are used for hacking? • 1.3.6.1.2.1.69.1.4.5.0 ▫ To figure out what the current cfg file name is for cable modem. • 1.3.6.1.2.1.10.127.1.1.3.1.3.1 • 1.3.6.1.2.1.10.127.1.1.3.1.5.1 ▫ To check Up/DownStream speed of cfg file • 1.3.6.1.2.1.69.1.4.4.0 ▫ To read TFTP Server IP of cable modem • 1.3.6.1.2.1.69.1.1.3.0 ▫ To reboot cable modem With some software and cheap hardware – hacking is pretty darn simple in a non-BPI+ environment © The Volpe Firm Confidential
  • 67.
    67 BPI/BPI+ in DOCSIS1.x / 2.0 • BPI: Baseline Privacy Interface ▫ Methods for encrypting traffic between the cable modem and the ▫ CMTS with 56bit DES encryption • BPI+: Baseline Privacy Interface Plus ▫ Implemented in DOCSIS 1.1 specs (Backwards compatible) ▫ Introduces X.509 v3 (RSA 1024bit) digital certificates & key pairs ▫ Authentication based on certificate hardware identity; validated when modem registers with a CMTS • Makes hacking a bit more difficult, however… ▫ Operators tend to leave “Self-signed certificates on ▫ During registration, there is no BPI+ security, all transactions are in the clear ▫ DOCSIS 1.x and 2.0 is still exposed to security breaches ▫ Even with Enforce TFTP, Masking TFTP file names, TFTP Proxy, etc. © The Volpe Firm Confidential
  • 68.
    68 Enhance DOCSIS 3.0& IPv6 Security • DOCSIS 3.0 Introduces ▫ 128 bit AES traffic encryption ▫ Early CM authentication and traffic encryption (EAE) ▫ Source IP address verification (SAV) ▫ TFTP proxy and configuration file learning ▫ MMH algorithm for CMTS MIC ▫ Certificate revocation ▫ Encryption support of new method of multicast messaging © The Volpe Firm Confidential
  • 69.
    69 Security Recommendation • Enable BPI+ and EAE • Use BPI+ Enforce • Disable Self-Signed Certificates • Use “Secure Provisioning” by leveraging SAV • Only allow CM software download via CVC • Disable Public SNMP access • Eliminate “Walled Garden” customer access points ▫ Walled Garden sites are the primary gateway for theft-of- service • Restrict access of your security department and policies to a limited, trusted number of people ▫ Security breeches often come from within © The Volpe Firm Confidential
  • 70.
    70 For more informationgo to: http://volpefirm.com © The Volpe Firm Confidential