Table Of Contents
This document defines a performance-management (PM) architecture that will allow service providers (SPs) deploying code-division multiple access (CDMA) data services to track the ongoing performance of their network from end to end. The solution should provide visibility not only into the Cisco domain, including IP platforms such as the Packet Data Service Node (PDSN) and Layer 2 switches, but also into the radio domain of the wireless infrastructure.
The PM architecture focuses on the interactions between Cisco and third-party network-management systems and Cisco network elements (NEs).
The managed Cisco NEs in a typical packet service CDMA network include:
•Cisco Catalyst® Ethernet Switches (Catalyst 6509)
•Cisco Packet Data Serving Node (PDSN)
•Cisco routers (Cisco 3662, 7xxx, and so on)
•Cisco MGX™ 8850 Edge Concentrator
•Other NEs in the future
The following topics are covered in this document:
•Cisco CDMA Operations Administration Maintenance and Provisioning (OAM&P) architecture
The Cisco Performance Management philosophy provides the following benefits to CDMA SPs:
•Assessment of quality of service (QoS) as experienced by customers
•Ability to offer key differentiators based on service-level agreement (SLA) monitoring
•Comprehensive network performance analysis
•Cost savings with elimination of overprovisioning
•Sharp decline in unplanned network outages
The Cisco CDMA OAM&P Architecture
End-to-End Network View
Cisco CDMA NEs, including the PDSN and its neighbor Catalyst Switches, are managed through the CiscoWorks2000 for Mobile Wireless bundle (CW4MW), which is a suite of EMS applications that enhances the delivery of wireless next-generation services leveraging Cisco mobility platforms such as the PDSN. It includes:
•Mobile Wireless Fault Mediator— This Telco-grade fault solution provides intelligent device discovery, alarm filtering and correlation of the PDSN and GGSN and their neighboring Catalyst switches. In addition, MWFM seamlessly integrates with Network and Service-layer Fault OSS to provide a complete network monitoring solution.
•CiscoWorks2000—The CiscoWorks2000 line of products provide solutions targeted at the wide-area and local-area operations of communications networks.
Cisco MGX 8850 platforms switch the traffic between the radio network and Cisco PDSNs. They are managed by the Cisco WAN Manager solution.
Figure 1 shows a typical Cisco PDSN network alongside the radio infrastructure. The service-layer PM application is located in the Network Operations Center (NOC) area and is provided by Cisco ecosystem partners.
Figure 1 CDMA OAM&P View
Cisco Mobile Wireless PM Architecture
A Telecommunications Management Network (TMN)-based network diagram is presented in Figure 2. Network and service-level PM solutions such as Metrica/(NPR) collect performance statistics either from the element-management system (EMS) or directly from NEs and provide monitoring and analysis functions. As described in the following sections, CiscoWorks2000 also provides PM and troubleshooting capabilities with CiscoView, Cisco Internetwork Performance Monitor (IPM) and nGenius Real-Time Monitor applications.
Initially, the different PM solutions collect statistics directly from the Cisco devices. The dotted lines indicate future interfaces between management systems.
Figure 2 TMN-Based Performance Management Diagram
The PM process involves several steps:
•Gather performance data on those variables of interest to network administrators
•Analyze the data to determine baseline levels
•Determine appropriate performance thresholds for each important variable such that crossing of these thresholds indicates a network problem worthy of attention
Management entities continually monitor performance variables. When a performance threshold is exceeded, an alert is generated and sent to higher-level management systems such as the Cisco Info Center for further processing.
Table 1 shows the types of statistics that are available from Cisco devices and the applications that provide the overall PM functionality.
Table 1 Performance Metrics from platforms and applications
The ATM/Frame Relay, IP, and wireless statistics that can be collected from Cisco devices are discussed in the next chapter.
Performance Monitoring and Reporting
Performance monitoring is used for observing and collecting data on a specified set of attributes associated with network resources to measure network performance.
This section defines the statistics that can be collected from the Cisco devices in the mobile wireless environment and then describes Cisco PM solutions at the element-management layer.
Cisco Performance Statistics
Cisco MGX-8850 Statistical Data
The ATM performance statistics available from Cisco devices in a typical CDMA environment are given in Table 2. This statistical data is stored in the NE Management Information Base (MIB) table; it can be retrieved via MIB variable polling of the Simple Network Management Protocol (SNMP) agent.
Table 2 Cisco MGX-8850 Statistical Data Provided by WingZ Application
Cisco WAN Manager collects the data directly from the MGX 8850, while WingZ aggregates it in summary reports and provides the statistics given table 2. Additional information on WingZ is provided later in the document.
Generic IP Statistical Data
The standard IP statistics for Cisco platforms are defined in various MIBs, such as RFC 1213, CISCO-ENTITY-MIB, and so on. Table 3 provides a sample of statistics available from MIB groups such as IF, IP, ICMP, and TCP. Performance-monitoring applications retrieve them from the SNMP agent.
Table 3 Generic IP Statistical Data
Cisco PDSN-Specific Statistical Data
In addition to IP generic statistics, Cisco PDSNs also provide CDMA operating data to allow PM applications to periodically read throughput and traffic volumetrics.
Tables 4 through 6 describe statistics available from the CISCO-CDMA-PDSN-MIB. This MIB is implemented within Cisco PDSN Releases 1.0.1 and 1.0.2. A new MIB (and variables) will be introduced with PDSN Release 1.1 and later.
Table 4 PDSN System and Data Session Statistics
PM Categories Statistics Description Throughput
Total number of flows currently using simple IP, MoIP, or proxy MoIP service
Total number of data packets (or octets) sent/received to/from mobile user
Number of existing IP flows for an established session
Average data rate per session1
Total number of A10/A11 session failures occurring since PDSN agent restarted
Total number of incoming/outgoing data packets dropped by PDSN
Number of seconds granted/remaining before registration is considered expired
The current number of sessions established in the system
Average duration of data session1
1 Future implementation
Table 5 Packet Control Function Statistics
Table 6 R-P Registration Statistics
The following table lists the statistics for the RAN PDSN Interface (R-P) registration, which are similar to those for the R-P registration update.
When the performance data is available from the Cisco platforms, the following applications can provide IP PM functionality at the element-management layer, as represented in Figure 2 earlier in the paper. CiscoWorks2000 applications will provide visibility into IP and wireless metrics, while the Cisco WAN Manager solution offers ATM/Frame Relay statistics monitoring and analysis.
Cisco Performance Monitoring Solutions for IP and Wireless
CiscoView is a Web-based device-management application that provides dynamic status, monitoring, and configuration information for the broad range of Cisco internetworking products. CiscoView displays a physical view of a device chassis, with color-coding of modules and ports for at-a-glance status. It provides real-time monitoring of key information that relates to device performance, traffic, and usage, with metrics such as utilization percentage, frames transmitted and received, errors, and a variety of other device-specific indicators.
Figure 3 Figure 3: CiscoView
Specific to the CDMA context, CiscoView will display in charts PDSN performance metrics such as:
•Current sessions ratio
•Current PCF ratio
•Simple IP flows
•Mobile IP flows
•Proxy MoIP flows
•Session failures count
The user has the option to set polling rate at which the statistics are retrieved.
Cisco Internetwork Performance Monitor
Cisco Internetwork Performance Monitor (IPM) is a network response time and availability troubleshooting application. (See Figure 4.) This application empowers network engineers to proactively troubleshoot network-wide performance to diagnose congestion and latency problems utilizing real-time and historical statistics.
Figure 4 Cisco IPM
With Cisco IPM, network managers have the tool they need to identify performance problems, locate performance bottlenecks, diagnose latency and jitter, and identify performance trends in the network.
Cisco IPM enables network managers to perform path and hop performance analysis, thereby simplifying the identification of network devices that are contributing to network-performance problems. Cisco IPM can determine the possible network paths used between two network devices and display the response time for each of the router hops in each path.
Cisco IPM measures network performance based on the "synthetic traffic generation" technology within the Cisco IOS® Software, which is known as the Service Assurance agent (SA agent). The use of synthetic traffic by Cisco IPM gives the network manager a high degree of flexibility in selecting the end points in a network between which network performance will be measured. This flexibility makes Cisco IPM a highly effective performance troubleshooting tool
Cisco nGenius Real-Time Monitor
The Cisco nGenius Real-Time Monitor (RTM) is a new Web-enabled system that delivers multiuser Web access to network-wide, real-time Remote Monitoring (RMON) information for monitoring, troubleshooting, and maintaining network availability. (See Figure 5.)
Figure 5 Cisco nGenius Real-Time Monitor
The RTM Traffic Monitor and Packet Analyzer applications graphically report and analyze device-, link-, and port-level RMON collected traffic data from the following RMON-enabled devices:
•Catalyst Switches (Catalyst 5000 and 6000)
•Internal network analysis modules
•External Cisco SwitchProbes
The powerful graphic capabilities within this application offer both real-time analysis of traffic behaviors and network usage information as well as proactive trending data for network planners and managers.
Cisco Performance Monitoring/Analysis Solutions for ATM
Cisco WAN Manager
The Cisco WAN Manager (CWM) manages the Layer 2 switch infrastructure of the Cisco MGX 8850. CWM is an element-management system with WAN network visibility that enables operations, maintenance, and management of multiservice WAN networks. CWM provides comprehensive configuration, connection, fault, performance, and security management through graphical user interfaces (GUIs) and flow-through interfaces.
Performance and Capacity Management
CWM Statistics Agent software collects comprehensive network statistics for cost allocation, performance management, and capacity planning. The Statistics Agent uses Trivial File Transfer Protocol (TFTP), which is optimized for bulk data transfer, and can upload in excess of three million usage statistics per hour per agent. The data is then stored in a standard Sequenced Query Language (SQL) database for historical reporting and trend analysis.
Statistics Collection Manager
The Statistics Collection Manager (SCM) provides a forms-based interface to establish and modify statistics collection policies for the network. You can configure statistics collection policies such as which statistics to collect, and collection interval periods for a node, port, or private virtual circuit (PVC). SCM provides extensive error-handling and logging capabilities that enable reliable collection of statistics for performance or billing applications. (See Figure 6.)
Figure 6 Statistics Collection Manager
WingZ Report and Summary Report
CWM Statistics Reports are generated through a graphical reporting package based on the Informix WingZ Report application. CWM also provides node utilization reports not based on WingZ. These reports are obtained through the Summary Report application.
Both the WingZ Report and the Summary Report applications provide a point-and-click GUI to generate reports based on information collected by the statistics agents. For each report, the user identifies certain criteria, such as network object, type of statistics, granularity, report interval, and graphical format, depending on the report application selected.
For the WingZ Report, the report agent queries the Informix database and generates a report in the desired format, such as line, bar, three-dimensional (3-D), or tabular chart, thus scalability of statistics collection is an important differentiator of CWM.
The second phase of PM is performance analysis, an analysis of the performance data collected during the performance-monitoring stage. This analysis provides information on whether network congestion is occurring and helps the management system to determine if performance is adequate for existing services and planned new services.
Cisco recommends that wireless service providers take advantage of the breadth of feature-rich PM applications available from the Cisco ecosystem partners. The philosophy behind this approach is described below.
Cisco Systems, Inc. has worked with best-of-breed application vendors and systems integrators to define and deliver integrated solutions that will help wireless service providers speed time to market and revenue for Internet Protocol (IP)-based New World networks and services.
Cisco and its partners are dedicated to defining and delivering solutions and business processes for New World Operations Support Systems (OSSs) deployed in the mobile wireless environment. The partnership brings together product and implementation services from alliance partners with best-in-class application software from third-party vendors to complete the integrated, end-to-end OSS offerings. The partners will also offer postimplementation support and testing to help service providers measure the effectiveness of their New World communications infrastructures.
Cisco ecosystem partners have developed performance systems with analysis that include real-time historical plotting of the following data:
•PDSN, link, and path availability
•Throughput, congestion, and errors
ADC Metrica is an ecosystem partner that has developed a PM solution specifically for CDMA networks. The solution will monitor, analyze, and control performance management of the radio domain, the CDMA data portion, the Layer 2 switch infrastructure, and the IP cloud.
Metrica/NPR, which is part of the Metrica Service Assurance family of products, consists of a set of equipment interfaces, a database, and reporting modules. Interfaces are available for major equipment suppliers, including facilities for mapping each vendor's counters onto a generic network-wide data model. Other NPR components allow for calculation of daily, weekly, and monthly summary data based on a rich set of analysis functions. Standard reporting modules are provided to allow textual and graphical reporting of raw and summary data. Included are modules for traffic forecasting and an ad hoc point-and-click query interface.
For additional information on the ADC Metrica/NPR solution, refer to the following Web page: http://www.adc-oss.com/products/npr.htm
This white paper documents how Cisco Systems meets the key requirements of New World mobile wireless service providers for their performance-management needs by providing:
•TMN-based open management architecture
•Relevant performance statistics available from Cisco CDMA platforms
•Off-the-shelf CiscoWorks2000 applications to monitor the generic IP performance
•Best-of-breed approach that takes advantage of the Cisco ecosystem philosophy
•PM solution to support CDMA multivendor and multitechnology networks
Most importantly, Cisco wireless operations solutions have been developed and designed based on the unique insights, experience, and technical prowess of the leading practitioner of IP networking. The solutions are integrated with, and complemented by, the industry's most acclaimed infrastructure technology solutions, as well as by a comprehensive portfolio of support services.
Rayes, A., and K. Sage. "Integrated Management Architecture for IP-Based Networks." IEEE Communications, April 2000.
For a complete list of Cisco device MIBs, refer to: http://www.cisco.com/public/sw-center/netmgmt/cmtk/mibs.shtml