DOCSIS 3.0 Broadband Intelligence Using IPDR to maximize new service opportunities

Transcription

1 DOCSIS 3.0 Broadband Intelligence Using IPDR to maximize new service opportunities Better Networks for Everyone Abstract When combined with DOCSIS 3.0, IPDR creates a powerful tool for Cable Service Providers. It is the most effective way to observe and manage networks, subscribers and traffic in an application agnostic manner. Providers can apply enhanced visibility to address new used cases in capacity management, service assurance and subscriber usage control. Further, IPDR enables broadband business intelligence - allowing new metrics and insights into business performance and overall subscriber experience. Presented in this whitepaper is an overview of the enhanced DOCSIS 3.0 management capabilities introduced by IPDR. This includes an overview of IPDR's advanced Service Definitions and protocol modes along with a description of new use-cases in service and network management. An investigation of how service providers can leverage Pipeline's unique capabilities to fully benefit from the rich intelligence data embedded in their DOCSIS 3.0 CMTS devices is also included.

2 design develop deploy Contents Introduction 3 The Motivation for IPDR in DOCSIS 3 Business Benefits of IPDR 4 New IPDR data enables new use cases 4 D3 Service Definitions 11 The evolution of IPDR in DOCSIS 10 Using Pipeline to maximize the D3 opportunity 11 Conclusion 12 About the Author 13 Figures Examples of new use cases enabled by IPDR 6 Excerpt from SAMIS Type-I SD 7 RF domain representation of DOCSIS upstream 9 Pipeline IPDR data capabilities summary 11 Pipeline s role in IPDR enabled infrastructure 12 2

3 DOCSIS 3.0 Broadband Intelligence Using IPDR to maximize new service opportunities Introduction Broadband Intelligence builds upon the technologies of DOCSIS 3.0 and IPDR to enable Business Intelligence for Cable Service Providers. Broadband intelligence uses the architectural principles of real-time event and stream processing of record flows from DOCSIS networks in order to provide cable operators with the capability to analyze and understand the relationships between their network, subscribers, services and overall business objectives. Version 3.0 of the DOCSIS standard was created to afford greater speeds to consumers and a to expand the opportunity for cable service providers to offer new services. Included with DOCSIS 3.0 (D3) is a powerful new tool for managing networks & subscribers using IP Detail Records (IPDRs). IPDR goes beyond what traditional network management protocols have attempted by introducing rich new data that opens the door to new levels of service assurance, network optimization, and broadband business intelligence. Though originally intended only for subscriber accounting management applications, IPDR in DOCSIS 3.0 has extended to address other use cases by offering access to a rich new data source providing new metrics. The Motivation for IPDR in DOCSIS IPDR was brought together with DOCSIS to address one critical issue of network data collection: scalability. SNMP, a general purpose network management protocol, could almost scale to the level of per CM monitoring in the million modem networks that, at the time, were just starting to come to fruition. However, as of DOCSIS 1.1, operators needed to scale to the level of 4, 6 or even 8 Service Flows per CM. SNMP had a number of limitations that prevented it from reaching that scale for the polling intervals required. IPDR/SP was a new protocol first introduced in the IETF (as CRANE) and later as part of the IPDR Forum (now maintained by the TMForum). IPDR/SP was developed specifically to address the limitations of existing network management protocols and to provide the internet Protocol with a detail record akin to the Call Detail Record (CDR) used for usage accounting in the telephony world. It uses persistent, reliable connections, efficient acknowledgments and a compact data encoding. In short, it was designed specifically to address the well-known and well-understood scalability problems of SNMP (especially when used for repeatedly acquiring time-series data). In DOCSIS 1.1 and DOCSIS 2.0 use of IPDR was limited to its original scope: usage metering and accounting. While the IPDR/SP protocol can support any type of management data, in the 3

4 Cable world IPDR became almost synonymous with SAMIS (Subscriber Accounting Management Interface Specification). SAMIS was the original DOCSIS IPDR/SP Service Definition or SD (a SD is the IPDR/SP equivalent of a MIB). While SDs can be defined for any set of management data, just like a MIB, the association of IPDR/SP with SAMIS was so strong that IPDR/SP risked being pigeon holed as being equivalent to SAMIS. When DOCSIS 3.0 came a long the million-node network was transforming into the 10-millionnode network and operators NMS experts were realizing that their scalability problems with SNMP were not going away. Thus, DOCSIS 3.0 began to apply IPDR/SP to a variety of other use cases generally for data sets that required regular, periodic polling (in SNMP) for trending or other long-term tracking. Now a formal DOCSIS 3.0 requirement, new data generated by IPDR/SP can be applied to a number of diverse Cable Service Provider use cases ranging from service assurance to fraud detection and automated subscriber consumption management. This whitepaper examines new metrics, data models, and use cases scenarios that include the following IPDR capability in DOCSIS 3.0 networks: Business intelligence Inventory management Customer care & diagnostics Security management Capacity management Network optimization Usage metering Policy management Service assurance 4

5 Business Benefits of IPDR Traditionally, the need for access to network data was limited to engineering and operations network management tasks. Today, however, competition and consumer demand for enhanced services and richer online experiences demand that business & product stakeholders within the service provider s organization now have access to network information in order to make educated data-driven decisions. For Cable Service Providers, the purpose of network visibility is to inform data-driven business, engineering, and operations decisions while detecting and enforcing policy in the network. The advanced SDs of DOCSIS 3.0 provide a rich new dataset to drive sophisticated forms of analysis - revealing the behavior of subscribers, network resources, and services. The advanced SD of IPDR/SP provide new data to service providers enabling them to answer key business questions, such as: How are my network assets performing? Am deploying my capital effectively? Using advanced SDs; providers now have visibility into traffic behavior on the HFC node level to make targeted decisions regarding capacity resources and service traffic volume trends down to the neighborhood, office, or subscriber premises. How profitable and efficient are my service tiers and product offerings? By comparing rich data sets describing service tier traffic and subscriber behavior data to subscriber tier revenue, providers can now understand the relationship between capacity resource costs and Key Performance Indicators (KPIs) for business such as product tier ARPU. What are my subscribers experiencing? For providers, service assurance and enhancing the subscriber experience have become key competitive differentiators. Where before consumers were impressed primarily with just increases in speed, subscribers are now performance and availability aware. If collected and applied properly, the new data enabled by IPDR s advanced SDs empowers operators with unprecedented insight into the subscriber experience, and exposes hidden opportunities to optimize both DOCSIS networks and services. New IPDR Data enables new use cases The DOCSIS 3.0 SDs beyond the initial SAMIS SD are sometimes referred to as the Advanced SDs as they provide a powerful set of solutions to existing and forward-looking management problems. The table below provides a summary of all DOCSIS 3.0 SDs defined and supported in qualified CMTS devices. Service Definition (SD) Description Example Use Cases Subscriber Account Management Interface Specification (SAMIS) Diagnostic Log Spectrum Measurement Provides per CM device, per Service Flow byte counts. Provides CMTS information and topology, QOS information, CPE information. Provides detailed diagnostic information on a single CM device from the perspective of the CMTS. Provide representation of per upstream RF spectrum equivalent to a simple spectrum analyzer in the CMTS. - Capacity planning - Usage metering - Business intelligence - Policy management - Service assurance - Network optimization - Customer care & diagnostics - Service assurance - Network optimization - Network optimization

6 - Service assurance CMTS CM Registration Status CMTS CM Upstream Status Information CMTS Topology CPE CMTS Utilization Statistics Provides detailed view into CM device status, registration state, and CMTS topology relationships as perceived by the CMTS. Provides per CM device upstream physical layer signal quality information. Provides CMTS topology to RF/HFC topology relationships showing connectivity of downstream and upstream channels to fiber nodes. Provides per CPE information per CM device for host(s) on the subscriber s network (MAC, IP, FQDN) Provides the CMTS MAC domain, channel identifier, and upstream or downstream interface attributes and counters. In the upstream, describes detailed IUC mini-slot counts. - Customer care & diagnostics - Capacity planning - Service assurance - Inventory management - Security management - Network optimization - Customer care & diagnostics - Service assurance - Capacity planning - Network optimization - Inventory management - Capacity management - Business intelligence - Service assurance - Customer care & diagnostics - Inventory management - Security management - Inventory management - Service assurance - Capacity planning Figure 1. Examples of new use cases enabled by IPDR Advanced IPDR Service Definitions Anatomy of a Service Definition Simply put, an IPDR SD (SD) is a data model for managed objects described using an XML schema. Thought of another way, a SD is to IPDR what a MIB is to SNMP. It is an extensible language used for the expression of objects and attributes that are of significance from a network and subscriber visibility perspective. DOCSIS 3.0 defines a collection of these SDs which are summarized in this section. Figure 2. Excerpt from SAMIS Type-I SD 6

7 SAMIS - Subscriber Account Management Interface Specification Use Case(s): Capacity management, usage metering, business intelligence, policy management, service assurance network optimization The SAMIS SD was the first SD defined for DOCSIS networks to answer the need for accurate and reliable Service Flow usage metering. Originally introduced as an optional CMTS feature in the DOCSIS 1.1 specification, the SAMIS SD has evolved considerably over time to become a normative requirement for DOCSIS 3.0. Along with service flow byte counts on a per CM basis, the original SAMIS SD for DOCSIS 1.1 and 2.0 also included ancillary data to describe the topological context and status of the CM device. As of DOCSIS 3.0, there are now two SAMIS SDs defined: Type-I and Type-II. Both are described below: The SAMIS-TYPE-I SD is akin to the DOCSIS 2.0 version in that it is verbose and includes twenty-eight record elements to be included with each CM Service Flow record. These objects include the Service Flow statistics and configuration, as well as the CM s topological relationship with the CMTS, its registration status, and other CMTS status information. The SAMIS-TYPE-II SD defines twenty record element objects to be included for each CM Service Flow. It is a SD more compact schema defining the Subscriber Account Management (SAMIS) Type 2 IPDR data record. SAMIS- TYPE-2 is based on the optimized streaming model where only updated fields are included in each streamed record. The TYPE-2 record does not include the details on CM or CMTS status found in its TYPE-I counterpart. Diagnostic Log Use Case(s): Customer care & diagnostics, service assurance, network optimization There are three new SDs that deal with diagnostic logs (aka flap lists ). The first of these is the DIAG-LOG SD. This SD is primarily of interest due to two counters it contains that relate to flapping or a cable modem repeatedly going up and down. The first DIAG-LOG counter is the RegCount which increments each time the CM re-registers with the CMTS. This is useful for detecting modems that try to register, but generally don t reach a fully online state. It can be used for detecting any number of potential problems such as registration problems or downstream sync problems. CMs having these types of errors are, at best, intermittently fully online. The other counter of interest is the RangingRetryCount, which counts how many times the CM has retried DOCSIS ranging (e.g. power adjustment, etc). High values of this counter can indicate upstream RF problems (e.g. common path distortion, laser clipping, etc). This data is available on an ad hoc basis by polling the CMTS. The second of these is the DIAG-LOG-EVENT SD. This SD is very configurable. It allows configuring a set of registration events that are of interest for monitoring. When one of the configured events occurs an IPDR record is sent with the CM MAC, the time the event occurred, type of event that occurred and any associated event text. The set of registration events that can be monitored per this SD are: initial ranging, start EAE, DHCP start/complete, configuration download start/complete, registration start/complete, etc. The concept here is that this SD, by providing the raw events for the Diagnostic Log, could facilitate a Diagnostic Log external to the CMTS to be created. 7

8 Virtually identical to the DIAG-LOG-EVENT SD is the DIAG-LOG-DETAILED SD. The main difference between these two SDs is that the latter provides counters for the configured events while the former just provides each individual event as it occurs. The DIAG-LOG-DETAILED SD can also be polled or the entire table can be provided on a periodic basis whereas the DIAG-LOG-EVENT SD can only be captured on an event-by-event basis. The counters incorporated into the DIAG-LOG-DETAILED SD allow the operator to narrow down the root cause of cable modem flapping for CMs that show up in the DIAG-LOG. It does this by counting the occurrence of various registration events. For example, if the number of times the CM started a configuration file download and the number of times a CM completed a configuration file download are different then there may be problems with the CM s connectivity to the configuration file server. Spectrum Measurement Use case(s): Network optimization, service assurance The SPECTRUM-MEASUREMENT SD provides the ability to perform upstream in-channel spectrum analysis capability. This allows an operator to not only determine how much noise and interference is occurring within the channel, but also where in the channel the interference is located. This data can be polled from the CMTS or delivered on a periodic basis. The spectrum measurements provide data on the energy within the channel (excluding any CM transmissions). The data is represented as a set of frequency bins with a corresponding measurement of the amount of energy found in that frequency range. (The CMTS is mandated to support at least a 25kHz bin spacing for the frequency bins.) All spectrum measurements occur prior to demodulation (if a CM signal is present) and while the effect of ingress filtering is not included in the measurement, the effect of the receive-matched filter may be. Figure 3. RF domain representation of DOCSIS upstream channel based on IPDR data 8

9 CMTS CM Registration Status Use case(s): Customer care & diagnostics, capacity management, service assurance, network optimization The CM-REG-STATUS SD provides information on the state of the CM s connectivity to the CMTS as well as topology information critical to locating the CM within the cable network. For example, it includes the MAC domain interface as well as the CMTS MAC Domain CM Serving Group, which is the set of all channels that the CM can use to receive or transmit data. In addition it provides both IPv4 and IPv6 address information for the CM. All CMs supported by the CMTS have an associated CM-REG-STATUS record and the entire set of CM information can either be provided periodically or polled from the CMTS. This SD can be used to monitor changes in CM registration status or IP addressing and it can also be used in conjunction with other SDs to perform topology-aware analysis of management data. For example, it could be combined with data in the TOPOLOGY SD and the SAMIS-TYPE-2 SD to provide equivalent usage-to-topology mapping that is found in the more verbose SAMIS-TYPE-1 SD. This type of approach trades reduced network bandwidth and CMTS load (by using the less redundant SAMIS-TYPE-2) for increased back-office complexity. (Pipeline 4.0 supports either approach.) CMTS CM Upstream Statistics Use case(s): Customer care & diagnostics, capacity management, service assurance, network optimization The CMTS-CM-US-STATS SD is focused on monitoring the RF performance of a CM on each of the upstreams it transmits on. To this end it provides metrics such as receive power (at the CMTS), signal-to-noise, micro-reflections, codeword error data, etc. An operator can utilize these metrics to identify CMs that are transmitting at a power level that is out-of-spec relative to the operator s plant standards or to determine which CMs are experiencing excessively high codeword error rates. This data can be used to inform customer service representatives handling calls about intermittent or on-going service problems reported by an individual subscriber. Further, by tying this data to other IPDR/SP topology data sources this could also be utilized to drive directed plant maintenance. CMTS Topology Use case(s): Inventory management, capacity management, business intelligence, service assurance The TOPOLOGY SD isn t particularly interesting in isolation. It provides the association between a Node s MAC Domain CM Serving Group and the channels that comprise it. That is to say, for each MAC Domain CM Serving Group associated with each Node this SD provides the list of channel ids (both upstream and downstream) that are part of the Serving Group. The real power of this SD is when it is combined with other SDs. In the past, to perform any number of FCAPS network management tasks in a topology-aware way required integration of the NMS with the Node Combining Plan. This required substantial back-office integration, which was daunting enough that few operators have this type of capability. With this data now present in the network elements (namely the CMTSes) via a single protocol and a coherent data model, it makes the task of creating these topology-aware back-office systems much more achievable. 9

10 Another less obvious use of the Topology SD is for auditing. DOCSIS 3.0 channel bonding requires topology information to be configured into the CMTS and mis-configuration can lead to service issues. The Node Combining Plan usually drives CMTS configuration of RF network topology and this SD reflects the CMTS configuration thus allowing the actual configuration to be compared against the intended configuration in the Node Combining Plan. CPE Customer Premises Equipment Use case(s): Customer care & diagnostics, inventory management, security management The CPE SD tracks the association of CPE IP addresses to CMs. Every time a new (i.e. not in the CMTS DHCP gleaning/arp tables) CPE appears to the CMTS it triggers the transmission of an IPDR record. This record contains the CM MAC address and the associated CPE MAC and IP (v4 or v6) address for the new CPE. This data is primarily useful to detect address spoofing and can be utilized to detect cloned CMs as well. The full CPE SD table can also be polled from the CMTS with an ad-hoc session. CMTS Utilization Statistics Use case(s): Inventory management, service assurance, capacity management The CMTS Utilization SD provides detailed information regarding the current utilized capacity of both upstream and downstream interfaces. In the upstream, the Utilization SD expresses interface capacity in terms of mini-slots allocated in terms of DOCSIS Interval Usage Codes (IUCs). In this way, the utilization of the upstream interface (channel) can be monitored with a level of precision more meaningful within DOCSIS networks than the more generic iftable equivalent traditionally used with SNMP. Likewise, in the downstream (channel), the CMTS Utilization SD expresses CMTS interface allocation in terms of total bytes of capacity and total bytes used. The Evolution of IPDR in DOCSIS While SAMIS has evolved since it was introduced in DOCSIS 1.1 its basic elements have largely remained the same throughout the DOCSIS 2.0 spec life cycle. For better or for worse, the stability that the industry has enjoyed with SAMIS has run its course. The changes of DOCSIS 3.0 Topology with bonded channels, etc. meant that SAMIS had to change and the desire of operators to make SAMIS less redundant First off, SAMIS now comes in two flavors SAMIS-TYPE-1 and SAMIS-TYPE-2. The SAMIS-TYPE-1 SDs is the most like the DOCSIS 1.1/2.0 SD. The main difference is that it no longer provides the downstream and upstream interfaces associated with the CM, while this makes sense given the many to 1 relationship between channels and CMs in a DOCSIS 3.0 world, it makes coexistence of legacy SAMIS workflows and DOCSIS 3.0 workflows more challenging. SAMIS-TYPE-2 is a more succinct version of SAMIS-TYPE-1. It omits all CM IP address information (assuming this data will be obtained by the CM-REG-STATUS SD) leaving only the CM MAC address as an identifier. Otherwise it provides much the same counters not only as SAMIS-TYPE-1 but also D2.0 SAMIS. 10

11 Using Pipeline to Maximize DOCSIS 3.0 Opportunity This whitepaper has described the new levels of visibility enabled by IPDR through the introduction of new SDs and protocol modes. However, service providers require the right software tools in order to take advantage of this capability embedded in their CMTSs and harvest this rich new data. The Applied Broadband Pipeline Broadband Intelligence System (BIS) was designed from the ground-up for this purpose. The market leading IPDR solution for DOCSIS, Capability Capability Overview Data Collection Data Transformation Data Remediation Semantic Routing Stream Processing Analytics & Reporting Get the data, really fast. Proven to be the world s highest performance and most reliable IPDR collection layer, Pipeline is capable of processing billions of record events per day using a small hardware footprint resulting in a 10:1 reduction in overall power, cooling, and rack-space. Abstract network complexity. Transform data streams from multiple sources and vendors over DOCSIS 1.1, 2.0, and 3.0 networks into portable formats and protocols enabling easy integration with all OSS/BSS applications and legacy systems. Remedy known issues with bad data at the edge. CMTS IPDR exporters are capable of generating erroneous data as a function of software defects in their system. Filter and repair known bad data at the edge, preventing known data issues from propagating deep into northbound applications. Data anywhere, anytime. Direct routing of CMTS source record streams from CMTS sources to multiple destinations delivering real-time data to an unlimited number of northbound applications without the added cost and complexity of a centralized database or enterprise service bus. Turn data into information. Stream processing and analysis providing real-time correlation and aggregation of service flows, subscriber events, and network topology to refine and distill data into information for use with metered billing, service analytics, and usage policy detection. Know now what you didn t know before. Powerful reporting and revolutionary visualizations fuel analytics and enable fresh new insights into the behavior of subscribers and capacity. Why? To make informed engineering, business, and policy decisions for a better network and happier subscribers. Policy Awareness DOCSIS Awareness Your network, your rules. Understand subscriber usage and bandwidth demand driven by your business rules and key performance indicators (KPIs). Gain insight into how your policies and best practices conserve bandwidth, enhance subscriber experience, and sustain a profitable network. Built from the ground up for DOCSIS 1.1, 2.0, and 3.0 networks. DOCSIS is both a powerful and complex broadband access technology. The aggregation, correlation, and analysis of DOCSIS IPDR events in real time requires deep domain expertise and algorithms unique to the technology. Figure 4. Pipeline IPDR data capabilities summary 11

12 Figure 5. Pipeline s role in an IPDR enabled Cable Service Provider management infrastructure Conclusion This whitepaper has introduced the reader to the new DOCSIS 3.0 SDs and provided a brief overview of the types of network and service use cases that provider s can now benefit from. In short, IPDR in DOCSIS 3.0 provides not only additional tools for managing a DOCSIS network, but also additional complexity. Complexity is inherent when attempting to manage a system as powerful and flexible as DOCSIS 3.0. But leveraging these Advanced SDs effectively will go a long way to addressing a number of the key network management challenges that come with the territory when deploying a system as complex as DOCSIS 3.0. Applied Broadband s Pipeline is the key to abstracting new complexities and scale while maximizing the value of DOCSIS 3.0 deployments and the new service models it enables. 12

13 About the Author Andrew W. Sundelin, Senior Architect Prior to Applied Broadband, Andrew was an early employee and Principal Architect at WildBlue Communications, a provider of high speed networking services over satellite. At WildBlue, he worked on adapting the DOCSIS MAC layer for satellite use and protocol optimization (e.g. HTTP and TCP) in a high delay environment. As an industry expert Andrew has worked extensively in network policy design, Quality of Service (QoS) implementation, capacity management, service quality assurance, and abuse mitigation systems and technologies. Andrew was a contributing author to the PacketCable Multimedia specification. Prior to these roles, Andrew was a system architect at CableLabs from At CableLabs, Andrew lead the specification team that wrote DOCSIS 1.1 as well as leading both the DOCSIS 1.0 MAC and the PacketCable QoS groups. Andrew has served on the SCTE High-Speed-Data MAC working group, as technical advisor for the CableLabs DOCSIS Certification Board, and has worked within both the IETF and IEEE on topics related to both wired and wireless DOCSIS. Andrew holds a B.Sc. in Computer Science and Russian Studies from Brown University and has completed all the course work for an MS in Telecommunications at the University of Colorado, Boulder.. About Applied Broadband Applied Broadband is a industry leading Broadband Intelligence and Service Assurance company for Cable Service Providers. We specialize in software implementation of policy-based networks, network optimization, and capacity management engineering practices and tools. Our customers are the many of the world s leading providers of voice, video, and data in the cable, satellite, and wireless marketplaces. The Applied Broadband team helped with the specification of DOCSIS 3.0 and to usher Cable s adoption of IPDR and is the leading provider of IPDR collection and mediation technology to the Cable industry. The Applied Broadband Pipeline Broadband Intelligence System addresses Cable operators need to collect, analyze, and distribute massive amounts of IPDR data for visibility into their networks, devices, services and subscribers overall experience. Pipeline provides a unified IPDR collection layer serving as an enabling foundation of visibility into the cable operators subscriber devices, services, and networks. The use cases and business benefits for Pipeline information based on IPDR data within a cable service delivery network are numerous. Applied Broadband is uniquely positioned to help its customers remain agile in the increasingly competitive broadband marketplace. We have worked with several companies, both large and small, in developing and launching numerous voice, video, and data broadband services and technologies. Our commitment to research and development along with innovative and practical software engineering has helped us to evolve several components, methodologies and models to address different customer scenarios. These reduce the cost, time-to-market, and risk of deployment, while enhancing the end subscriber s service experience. Applied Broadband, Inc Broadway, 2nd Floor Boulder, Colorado p f e sales@appliedbroadband.com 13