Data Analyzer Overview

The data analyzer is supplied with the ACC Base System product. It is a software based tool that allows real-time capture and analysis of X.25 traffic on one or more X.25 links simultaneously. It also allows analysis of ISDN traffic on the “D” channel signal and X.25 traffic on the “B” channel. It runs within an HP-UX based HP 9000 system. Although the data analyzer is designed to monitor X.25 or ISDN traffic from the ACC products, it can be attached to any RS-232 or V.35 X.25 connections with line speeds up to 1222 Kb/s.

Each X.25 connection to be monitored on an 8-Channel HP-PB or EISA card requires two ACC multiplexer ports, thus a single 8-channel ACC multiplexer card can support up to four analyzer sessions. Two ports are required on the 8-channel PCI card only if a non-ACC X.25 link is being monitored. The analyzer can provide up to 8 concurrent sessions by using the ports on two or more 8-Channel ACC cards. For ISDN traffic analysis, each connection requires only one sub-channel.

The Data Analyzer is composed of three major components:

Figure 1-1 “Overview of ACC based Data Analyzer” shows the relationships between these components, as well as the unique 'software-only' input configuration with respect to the 4-Channel and 8-Channel PCI ACC products. Configuration information is set up either in the ACC TTGEN configuration file, or dynamically by means of the convenient runc command.

Only one copy of the capture daemon runs in each HP 9000 system. It handles all analyzer sessions. The control of these sessions comes from one or more invocations of the Display program. The pdisplay program is designed to work on any HP-UX TTY device. Several copies of the pdisplay program can independently control several analyzer sessions simultaneously, or one pdisplay program may control multiple sessions.

Figure 1-1 Overview of ACC based Data Analyzer

The pcapture program can monitor all traffic on a particular X.25 link, or it can selectively monitor only traffic belonging to certain Virtual Circuits (VCs) on a link. The VCs of interest are identified by their Logical Channel Number (LCN); up to six filter LCNs may be specified for each X.25 analyzer session. By using this filter option, the size of the capture file can be minimized.

The pdisplay program also provides a filtering mechanism to select events from the capture file by LCN. Both these filtering mechanisms are independent. The pdisplay program also provides many options for displaying the captured X.25 or ISDN traffic (see “display” for a detailed description of the display command).