DOCSIS Characteristics

Transcription

1 In cooperation with DOCSIS Characteristics Presenter: Tony Holmes Rev. A00

2 Agenda Items for discussion DOCSIS/EuroDOCSIS Overview of Standards, Features & Benefits DOCSIS 3.0/EuroDOCSIS 3.0 CATV Market Dynamics DOCISIS DOCSIS 3.0 New Technical Directions & Features Network Preparation DOCSIS Confidential & Proprietary Information of VeEX Inc 2

3 DOCSIS Review Overview, Features & Benefits Confidential & Proprietary Information of VeEX Inc 3

4 DOCSIS An Overview DOCSIS system Enables transparent bi-directional of Internet Protocol (IP) traffic, between the cable system headend and customer location DOCSIS specification Defines PHY & MAC layer protocols for communication & Ethernet frame transport between CMTS & CM DOCSIS network comprises: Cable Modem Termination System (CMTS) located at the headend Cable Network - an all-coaxial or hybrid-fiber/coax (HFC) cable network Cable Modem (CM) located at the Customer Premise Transparent IP traffic Wide Area Network Cable Network (HFC) CMTS Cable Modem CPE CMTS/WAN Interface CM/CPE Interface DOCSIS Confidential & Proprietary Information of VeEX Inc 4

5 DOCSIS Milestones DOCSIS 1.0 (1999) 1 st products certified (CableLabs started project in 1996) Open standard for high-speed data over cable Modest security, Best-effort service DOCSIS 1.1 (2000) Quality-of-Service (QoS) service flows Baseline Privacy Interface (BPI+) Certificates Improved privacy & encryption process DOCSIS 2.0 (2002) Improved throughput & robustness on Upstream 64/128 QAM modulation & higher symbol rates with FEC Programmable interleaving to upstream channels DOCSIS 3.0 (2006) Channel bonding (4U/4D) for increased capacity IPv6 support Improved security (AES) DOCSIS Confidential & Proprietary Information of VeEX Inc 5

6 HFC Spectrum Allocation The frequency spectrum used in an HFC network is split into two parts: Downstream spectrum which delivers services from the headend to the end user Upstream spectrum for sending traffic from the end user to the operator DOCSIS Europe FM EuroDOCSIS US Analog Video PAL Digital Video MPEG/DVB + VOD EuroDOCSIS DS 5MHz GHz Upstream Downstream North America FM US DOCSIS US Analog Video NTSC Digital Video MPEG/DVB + VOD US DOCSIS DS 5MHz GHz Upstream Downstream DOCSIS Confidential & Proprietary Information of VeEX Inc 6

7 DOCSIS Upstream Physical Layer The DOCSIS Specification defines Modulation and Coding Schemes outlined in the following table for the Upstream DOCSIS Confidential & Proprietary Information of VeEX Inc 7

8 DOCSIS Downstream Physical Layer The DOCSIS Specification defines Modulation and Coding Schemes outlined in the following table for the Downstream DOCSIS Confidential & Proprietary Information of VeEX Inc 8

9 DOCSIS Power Ranging Ranging is used to synchronize CMs and align them with the CMTS TDMA requires coarse alignment (±800 nsec) S-CDMA requires accurate alignment (±1 nsec) CM sends a RNG-REQ message CMTS responds with a RNG-RSP message Contains Timing Adjust (Resolution = nsec) also Power adjust, Frequency adjust, Pre-EQ parameters Ranging is a two-step process: Initial maintenance (coarse time alignment) Periodic station maintenance (fine time alignment) DOCSIS Confidential & Proprietary Information of VeEX Inc 9

10 DOCSIS CM Protocol Stack DOCSIS MAC Forms part of the data link layer that supports topology dependent functions Uses services of the Physical Layer to provide services to the Logical Link Control (LLC) In the OSI 7-layer model, the Media Access Control is a part of layer 2, the data link layer. DOCSIS Confidential & Proprietary Information of VeEX Inc 10

11 DOCSIS Media Access Control (MAC) Media Access Control (MAC) Sub-Layer Controls access to the Physical Layer (the channel) Allows multiple users to share a communications channel Separate physical channels (upstream/downstream) controlled by the CMTS No direct peer-to-peer (CM-to-CM) communication Downstream MAC Only one transmitter (CMTS) and multiple receivers (CMs) Quality of Service (QoS) can be assured by: Token bucket rate limiting, Reserved data rates, Traffic Priority Upstream MAC Multiple transmitters (CM) with One receiver (CMTS) The CMTS arbitrates access to the channel Each upstream channel is described in mini-slots MAP messages are broadcast downstream to describe which CM can transmit and when Access Control is Reservation based DOCSIS Confidential & Proprietary Information of VeEX Inc 11

12 DOCSIS DHCP Server & Process DHCP Server Assigns IP addresses to client computers Addresses are leased to clients (Cable Modems or CPEs) for a period of time IP addresses can be reserved for specific clients or assigned from pools Clients may be authenticated based on their MAC address Address may be assigned from different pools based on extended options DHCP Process The DHCP server requests the following parameters from the Cable Modem (CM): IP address of the CM IP address of the TFTP Server (for DOCSIS Configuration file) IP address of the DHCP Relay Agent (if DCHP server resides on a different network) TFTP/DOCSIS Configuration file name Subnet Mask to be used by the CM Default IP Gateway Time of Day Server and SYSLOG Server IP address DOCSIS Confidential & Proprietary Information of VeEX Inc 12

13 DOCSIS Time of Day (TOD) Server Time of Day (ToD) Server Internet Time Protocol (ITP) per RFC 868 UDP and TCP requests honored on port bit value defining the number of seconds since 00:00 (midnight January 1, 1900 GMT) DOCSIS Confidential & Proprietary Information of VeEX Inc 13

14 DOCSIS TFTP Server TFTP (Trivial File Transfer Protocol) Server In accordance with RFC 1350 UDP port 69 Small and easy to implement with read and write to and from remote servers The following settings are mandatory in the TFTP configuration file: Network Access Configuration Setting Class of Service Configuration Setting The following settings are optional: Downstream Frequency Upstream Channel ID Vendor ID Baseline Privacy SNMP Write-Access Control, SNMP MIB Object & SNMP IP Address (if applicable) Software Server IP Address CPE Ethernet MAC Address Vendor-Specific Configuration (if applicable) DOCSIS Confidential & Proprietary Information of VeEX Inc 14

15 CATV Market Dynamics Confidential & Proprietary Information of VeEX Inc 15

16 Business Drivers Support new high bandwidth services of 50 to 100Mbps Migrate existing customers to higher tier services Better and more robust data encryption Provide more IP address space using IPv6 Limit and reduce node splits Reduce overall cost of CMTS ports Independent scalability of upstream & downstream DOCSIS Confidential & Proprietary Information of VeEX Inc 16

17 Higher Bandwidth Applications Digital Photos Web 2.0 Home Networks Gaming Data & VoIP MP3 WMV VOD DVR/PVR DVD Blu-ray You Tube SDTV HDTV Mobile Video ipod Walkman DOCSIS Confidential & Proprietary Information of VeEX Inc 17

18 Consumers greed for speed DOCSIS Confidential & Proprietary Information of VeEX Inc 18

19 Services driving Channel Bonding High bandwidth residential data and content Video and photo uploads Proliferation of social networking sites and applications IP Video over DOCSIS (VDOC) High definition Video to multiple devices PCs, hybrid STBs, portable devices High bandwidth Internet streaming High Bandwidth Video conferencing Cisco TelePresence Commercial service High bandwidth symmetrical data services Bonded E1/T1 circuit emulation High bandwidth Ethernet / L2VPN services DOCSIS Confidential & Proprietary Information of VeEX Inc 19

20 New Technical Directions & Features Confidential & Proprietary Information of VeEX Inc 20

21 Major Feature Overview Increased DS bandwidth Increased US bandwidth IPv6 Backwards compatibility IP Multicast Commercial Bonded Downstream Channels 56Mbps (RAW) each, 448Mbps Total Bonded Upstream Channels 27Mbps (RAW) each, 122Mbps Total IPV6 allows for 3.4x10 38 IP addresses IP addresses are lengthened from 32 bits to 128 bits Existing DOCSIS 1.0, 1.1 and 2.0 systems Scalable deployment with easy subscriber migration IPTV-type applications Efficient switched-video-like bandwidth usage E1 & T1 circuit emulation Network Security Early Authentication and Encryption (EAE) and AES 128bit encryption which is more robust and secure DOCSIS Confidential & Proprietary Information of VeEX Inc 21

22 Channel Bonding Channel bonding basically means data is transmitted to/from Cable Modems using multiple individual RF channels instead of a single channel Using DOCSIS 3.0, data is transmitted to cable modems using multiple channels DOCSIS Confidential & Proprietary Information of VeEX Inc 22

23 Throughput Compared DOCSIS Version Downstream Date Rates Annex B Upstream 1.1 ~ (38) Mbps (9) Mbps 2.0 ~ (38) Mbps (27) Mbps 3.0 (4 Channels) ~ (150+) Mbps (108+) Mbps 3.0 (8 Channels) ~ (300+) Mbps (108+) Mbps DOCSIS Confidential & Proprietary Information of VeEX Inc 23

24 Upstream PHY Modes Advanced Time Division Multiple Access (A-TDMA) Used widely in DOCSIS 2.0 and DOCSIS 1.1 systems CMs transmit one at a time, occupying the entire upstream channel during transmission Transmissions consist of a preamble, data burst, and guard time Better immunity to narrowband interferers and generally performs better above 15 MHz Synchronous Code Division Multiple Access (S-CDMA) Applicable to DOCSIS 2.0/3.0 systems only Multiple CMs able to transmit simultaneously with shorter preamble and no guard times Better immunity to burst noise and performance below 15 MHz 5MHz 42MHz or 65MHz DOCSIS Confidential & Proprietary Information of VeEX Inc 24

25 Downstream Channel Bonding Cable Modem Termination System (CMTS) A downstream packet stream or flow is distributed to a set of channels called the Downstream Bonding Group (DBG) Bonded packets are marked with a sequence # A Downstream Service ID (DSID) identifies a stream of packets Cable Modem (CM) Bonded packets can arrive out of order Bonded packets are re-sequenced using the sequence # The DSID is used re-sequence each flow or group of flows independently DOCSIS Confidential & Proprietary Information of VeEX Inc 25

26 Upstream Channel Bonding Upstream Bonding Packet Striping of a minimum of 4 channels Delivers in excess of 50 Mbps Single flow can consume entire bandwidth on multiple Upstream Channels Implements Continuous Concatenation & Fragmentation (CCF) Improved form of concatenation and fragmentation needed for DOCSIS 3.0 operation CMTS US1 Request 1000 bytes Grant 200 US2 P4 P3 P2 P1 Grant 300 bytes U3 Grant 500 bytes Cable Modem DOCSIS Confidential & Proprietary Information of VeEX Inc 26

27 Upstream Requests and Grants Cable Modem (CM) When a CM is ready to transmit data, it randomly selects a Request contention interval among all upstream channels Transmits a 7-byte REQ message to the CMTS, which identifies the CM (from the Service ID) and specifies the number of bytes in queue Retransmits the request, if there is no response from the CMTS Cable Modem Termination System (CMTS) Queues and prioritizes the incoming REQs Selects an upstream channel and reserves future mini-slots for the requesting CMs An individual request can be split into multiple grants on different channels Communicates the grants to the CMs via MAP messages DOCSIS Confidential & Proprietary Information of VeEX Inc 27

28 MAC Domain MAC Domain Defined as a sub-component of the CMTS Controls all DOCSIS functions on a set of downstream and upstream channels Contains at least one DS channel and one US channel Provides layer 2 data forwarding services between the CMTS and all the CMs registered to that particular MAC domain Implements all DOCSIS MAC management message exchanges with CMs across multiple US & DS channels using a common MAC address Implements load balancing of CMs and bandwidth of channels DOCSIS Confidential & Proprietary Information of VeEX Inc 28

29 New MAC Functions MDD Descriptor Describes Plant topology Plant Topology Describes fiber nodes and how they are split/combined Ambiguity Resolution Downstream Bonding Group (DBG) Upstream/Downstream bonding Sequencing for packet flows Dynamic Bonding Change (DBC) Bonding group attributes (low latency) CM status report Reports CM condition CM Control report Used to force actions such as reboot, or channel muting. DOCSIS Confidential & Proprietary Information of VeEX Inc 29

30 New MAC Management Messages (partial list) Message MDD B-INIT-RNG-REQ DBC-REQ DBC-RSP DBC-ACK DPV-REQ DPV-RSP CM-STATUS CM-CTRL REG-REQ-MP Description MAC Domain Descriptor Bonded Initial Ranging Request Dynamic Bonding Change Request Dynamic Bonding Change Response Dynamic Bonding Change Acknowledge DOCSIS Path Verification Request DOCSIS Path Verification Response Cable Modem Status Report Cable Modem Control Multipart Registration Request DOCSIS Confidential & Proprietary Information of VeEX Inc 30

31 During initialization, the CM downloads a configuration file from the cable operator The Config file defines: Quality of Service (QoS) parameters Priority, rate limiting, bandwidth guarantees, etc. Filters block Windows file sharing (netbios, SMB, CIFS) Privacy (encryption) parameters DOCSIS 3.0 CM Provisioning The CM then sends a Registration Request message to the CMTS containing the QoS parameters DOCSIS Confidential & Proprietary Information of VeEX Inc 31

32 Cable Modem Registration SYNC, UCD, MAP messages MDD message Scan digital channels & acquire QAM/FEC/MPEG lock of DOCSIS DS & DOCSIS PID Receive MAC Domain Descriptor (MDD) Message CMTS Tune additional downstream frequencies to determine service group B-INIT-RNG-REQ message Authentication & Key Exchange DHCP DISCOVER packet DHCP OFFER packet DHCP REQUEST packet DHCP RESPONSE packet TOD Request/Response messages TFTP Request/Response messages REG-REQ message REG-RSP message REG-ACK message BPI+ initialization if configured Cable Modem Select upstream channel listed in MDD Find Initial Maintenance interval in MAP messages Send RNG-REQ, receive RNG-RSP, adjust Txmitter Transition to ranging station maintenance Establish IPv4 or IPv6 communication via DHCP Download Configuration File (TFTP) Send REG-REQ, receive REG-RSP, send REG-ACK Provides Rx-Chan(s) Receive Rx-Chan(s) configuration Confirm all Rx Channels DOCSIS Confidential & Proprietary Information of VeEX Inc 32

33 Better Network Security Secure provisioning prevents unauthorized CMs from accessing the network Early Authentication and Encryption (EAE) Provides enhanced security Authenticates CM after power ranging and before DHCP process Signaling occurs in the MDD message (TLV 6) Enabled on either a per CM or per MAC domain basis CMTS Proxy Server CMTS acts as a TFTP server to the CM and as a TFTP client to the provisioning server Config parameters are enforced since CMTS receives the file first Provides config file authorization DHCPv6 authentication New MIC hash algorithm (MMH) DOCSIS Confidential & Proprietary Information of VeEX Inc 33

34 IPv6 in Cable Networks IPv6 is fundamental feature of DOCSIS 3.0 and provides numerous benefits: New address size and format bit vs 32 bit addressing Smarter packet simplified provisioning, built-in security, improved mobility, etc. Restores global connectivity removes Network Address Translation (NAT) CM operates in bridging or routing modes CM management stack operation - IPv4 only, IPv6 only or Dual mode MDD message contains IP type - conveyed between the CMTS and CM DOCSIS Confidential & Proprietary Information of VeEX Inc 34

35 Quick Summary DOCSIS 3.0 review Physically the same as DOCSIS 2.0 signals Consists of multiple QAM signals bonded logically together Bonded channels can be contiguous or non-contiguous: Contiguous - consists of frequency consecutive signals Non-contiguous interspersed with other carriers MPEG-2 transport for downstream signals QAM transport for upstream signals IPv4 or IPv6 support Enhanced security using EAE, etc. DOCSIS Confidential & Proprietary Information of VeEX Inc 35

36 Network Preparation Confidential & Proprietary Information of VeEX Inc 36

37 Basic steps for being prepared RF Bandwidth Availability Headend and Core Network Equipment Preparation Verify QAM64 Upstream Txmission Verify QAM256 Downstream Txmission DOCSIS 3.0 Modem Emulation IP/Ethernet Testing (Ping, FTP, RFC2544, Web) DOCSIS Confidential & Proprietary Information of VeEX Inc 37

38 Where can more RF bandwidth come from? Digital only systems Expand the plant to 1GHz Use unusable old analog broadcast channels Digital Simulcast migrating selected analog channels Node Splits Switched Digital Video for SD & HD content DOCSIS 3.0 requires a minimum of 4 to 16 downstream channels CMs are able to receive 4 DS channels spread across a 60MHz window DOCSIS Confidential & Proprietary Information of VeEX Inc 38

39 Bandwidth Management Reclaim Analog bandwidth for more digital spectrum More QAM channels for Digital Broadcast, VoD, SDV and DOCSIS Node splits Reduce the homes passed per HFC node, reducing contention/home for Unicast services Switched Digital Video (SDV) Transmit only the content being actively watched Efficient channel use Manage channel lineup, fill the gaps, and mitigate noise to utilize available spectrum 1GHz upgrade Make new spectrum for new CPE above 860 MHz Today 870MHz Soon 1GHz DOCSIS Confidential & Proprietary Information of VeEX Inc 39

40 How much can we gain with spectrum changes? Extending the US band from 65 MHz to 85 MHz New DOCSIS technology becoming available FM band is compromised Large network investment required Creating an upstream band 900 to 1000 MHz Adaptation of DOCSIS (RF up converter) Ingress noise issue mostly solved 862 to 1000 GHz considered an extension of DS band Huge investment in diplex filters and return amplifiers New upstream band above 1000 MHz Adaptation of DOCSIS (RF up-converter) Ingress noise issue solved Quality concern regarding passives and cables Investment in diplex filters and return amplifiers 250 Mbps 500 Mbps 1000 Mbps DOCSIS Confidential & Proprietary Information of VeEX Inc 40

41 Acknowledgements Information Sources DOCSIS Confidential & Proprietary Information of VeEX Inc 41

42 Acronyms/Abbreviations Common terms in DOCSIS systems DOCSIS Confidential & Proprietary Information of VeEX Inc 42

43 Thank You Questions? Tony Holmes Tel: (510) For more info on VeEX products Please contact our Caribbean Value Added Reseller (VAR) Confidential & Proprietary Information of VeEX Inc. 43