Reviews

Network Protocol Analyzers: A Window To The WAN

To view the Report card.

Wandel & Goltermann DominoWAN Internetwork Analyzer

The software can run on a notebook and communicate with the DA-310 via the standard parallel port. This is the approach also taken by the company's DominoLAN, which uses the same software, providing a consistent interface for WAN and LAN monitoring.

We particularly like this design philosophy. It's quite flexible and extensible but loses nothing in functionality. The module is small (it fits completely under standard notebook and is 1.3 inches high), light (only 3 pounds) and quite capable of being stuffed into a notebook carrying case for true portability. Up to eight stacked modules can be managed from one notebook for simultaneous monitoring of multiple LAN segments or WAN links. The DA-310 has replaceable modules for T1 (RJ-48C and bantam jacks), V-Series and ISDN Basic Rate Interface (BRI).

The Inte rnetwork Analyzer software provides the four basic functions of monitor, capture, examine and transmit. The monitor function provides statistics with some good graphic displays. The capture and examine views are consistent across the WAN and LAN interfaces.

As with all analyzer software tested, this is not a native Windows95 application. There is no support for long file names, a feature we find particularly useful when managing trace files. Wandel & Goltermann assured us that a Windows95 version is forthcoming.

There are additional toolbox applications that are quite useful. Most are DOS applications, but they appear to be well-behaved. We used the Frame Relay Monitor & Surveillance application (FRMOSU) to monitor and display DLCI-specific utilization graphs. DominoWAN makes excellent use of the Windows GUI with configurable child windows for viewing multiple captures (or for a different view of the same capture) and extensive context sensitive help.

We found the Internetwork Analyzer grap hics to be very helpful.

For example, in the T1 Interface Setup dialog box, selecting Test Mode while monitoring displays a block diagram of the test scenario.

The product's largest drawback is its lack of an expert system. At a minimum, Transport layer retransmissions should be flagged. The vendor has released the Domino Wizard for its LAN analyzer and is working on a Frame Relay Wizard for the DominoWAN.

Network General Corp. Sniffer Internetwork Analyzer Release 5.0

WAN analysis is made possible by the LM2000 line interface card (PC ISA) a nd associated software. The LM2000 software is distinct from the classic Sniffer application and provides extensive Level 1 and 2 tests and statistics. As with the SIA, this application runs under DOS, is text-only and makes extensive use of windows and function keys. The frame relay statistics screens are good, providing overall statistics for the frame relay link, a tabular display of DLCIs, detailed information per DLCI and a matrix display of status of virtual circuits. There also are detailed decodes of Level 2 and 3 protocols.

Although the LM2000 is similar to the SIA, it is a different product. The relationship is similar to the Analyzer versus Monitor functions of the classic Ethernet Sniffer product.

The LM2000 uses an external pod for access to T1 and fractional T1 circuits. You can configure some T1 parameters through software, but many are available only from the front panel of the T1 pod itself. For example, when monitoring DSOs, we were had to make our configurations from the pod. Anoth er limitation in Network General's WAN offering is the lack of support for asynchronous Point-to-Point Protocol (PPP). However, the company is testing this functionality in beta versions.

The single best feature of the SIA is its predictability. Anyone familiar with Network General's LAN offering will feel right at home: It works just as you'd expect. DLCIs are treated like any other addresses and filtering by DLCI is remarkably simple. You also can filter by data terminal equipment (DTE) or data communications equipment (DCE) from the address list. Expert symptoms and diagnosis are available for all Open Systems Interconnection (OSI) levels.