Analysis Service Elements

Analysis service elements are intelligent agents that continuously monitor activity on a WAN access circuit. ASE’s, whether embedded in a DSU/CSU or standalone equipment, do not interfere with the packet-processing of network elements (routers and FRAD’s), and do not generate a constant stream of management traffic from network management agent to NMS. Unlike conventional SNMP agents, ASE’s are proactive monitors: they generate alarms whenever user-defined thresholds for a set of performance-related events are crossed. This reduces, and in some cases eliminates, management overhead associated with the "polling" of network elements by a conventional SNMP NMS.

ASE’s maintain a revolving buffer of two days worth of network statistics. These statistics can be collected to form the historical database at any time convenient to the network (for example, at off peak times). The buffer can also be queried in real-time by a central management system, to verify physical access circuit integrity and to observe traffic traversing the access circuit. Traffic captured in real-time by ASE’s can also be collected to perform higher layer protocol decoding, post-capture filtering and interpretive display operations similar to a LAN protocol analyzer. Real-time traffic capture and collection is designed to impose very little overhead to the WAN circuit, and provides moment-by-moment insight into WAN circuit activity.

Network Performance Database

The collective data gathered from ASE’s forms a highly detailed and long-term network performance database containing physical access circuit, link layer and payload analysis data. The highly-detailed data collected by ASEs are stored in a two-day database "buffer", while aggregated data is summarized and retained in this database, limited only by allocated database storage. This Microsoft SQL Server 6.5 database is accessed through a toolset provided by any Visual UpTime™ console application.

Visual UpTime™ System Console Applications

The heart of the Visual UpTime™ WAN Service Level Management System is the MIC and PAM. The PAM (MIC) collects and processes network operational data, and prepares the data for reporting and display. The console application manages the network performance database and supports toolsets for monitoring, troubleshooting and analyzing WAN services.

Figure 3. Visual UpTime™ WAN Service Level Management (conceptual)

The subject company for this case study used an integrated version of the console application called a Management Integrated Console (MIC) to configure, monitor and troubleshoot their Frame Relay WAN. We used the distributed client-server management product, in which a Performance Archive Manager (PAM) provides client access to the management toolset from Platform Applicable Clients (PACs). Both the PAM and MIC are pre-installed and come ready to use on a Pentium PC operating under Windows NT Server 4.0. Platform Applicable Clients are available for many UNIX OS’s and any Microsoft Windows 32-bit OS. The toolsets available from the MIC or PAC console application are identified in Table 1.

Network Configuration	a toolset used to identify WAN networks and network elements such as sites and access lines that comprise the WAN network to be managed
Performance Monitoring	a toolset used to identify WAN performance events to be monitored and to configure ASE threshold values for these events
Event Processing	a toolset used to provide real-time event and alarm display and to manipulate logged ASE-generated events and alarms,
Troubleshooting and Statistical Analysis	a toolset used to view real-time and historical statistical information by access line, access channel, and PVC/Protocol,
Network Traffic Capture and Decoding	a toolset for accessing the protocol analysis or "packet-sniffing" functionality of the ASE, and
Planning and Reporting	a toolset for creating reports from the long-term database maintained by the PAC/PAM or MIC.

Table 1. Visual UpTime™ Toolsets

We examine these toolsets in detail as we describe the manner in which the subject company uses the Visual UpTime™ WAN Service Level Management System.

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