Performance and Diagnostic Tools

The TeVista suite includes the Enterprise Manager and the Network Asset Manager, which provide graphical inventories of network locations and devices. Also included are the Total Visibility Management and the Trouble Shooter components--performance and diagnostic applications that use TeVista's Visibility Agents as well as SNMP MIB II as data sources. I installed the entire suite in our Real-World Labs® using Syracuse University's 10,000-node network to get a sense of how many problems I could solve.

Total Visibility is the primary performance application within the TeVista suite. It uses Visibility Agents to collect real-time and historical packet performance, data tracking, in and out packets/octets and errors, which can be sorted by node, conversation, subnet and protocol. In most cases the data is displayed in tables with sortable columns, but a couple of graphical maps are available that show which devices have had successful or failed conversations. The graphs don't provide an effective display on their own, but you can create filters for data collection and isolate the conversations for select devices, which makes it much easier to focus on a single device.

Similar to 3Com Corp.'s DRMON (Distributed RMON), which used 3Com NICs to run separate data collectors, providing RMON visibility into switched networks, TeVista's proprietary Visibility Agent is "light" enough to sit on every desktop. Indeed during my tests using 300-MHz desktops, CPU utilization remained below 1 percent with a data sampling frequency of 10 seconds.

Total Visibility can aggregate Visibility Agents, letting you look at multiple switched segments as though they are one. And Total Visibility duplicates the multicast and broadcast traffic to avoid over reporting those statistics.

In addition to the information gathered by the proprietary Visibility Agents, TeVista also collects ping availability, SNMP MIB statistics and RMON data. The RMON data-collection instances are readable, and you can create new collections too.

TroubleShooting

The Trouble Shooter application is a real-time diagnostic tool displaying usage statistics. I was pleased to find a hierarchical, explorer-like view of all the objects in the database categorized by type, group and address. But this view should be in the Network Asset Manager, not the Trouble Shooter. The stats regarding packet utilization of each device or group were easy to access, but I had to edit the properties of the devices in a subapplication of the Trouble Shooter--the LAN Wizard. This makes no sense.

A second function of the Trouble Shooter is called LAN Hints. The idea behind it is to provide suggestions about possible errors. But I'm not quite sure if it worked. It may be that that we didn't have any problems on our network--we only received reachability errors that suggested the device was no longer transmitting.

The Conversation Explorer within the Trouble Shooter let me choose a node and show all the conversations that node was having. As long as the node had only 12 or so conversations, the information displayed was interesting. With more than this number of conversations, however, this tool is not useful: The conversations, shrunk to fit on the screen, look like nothing more than an interesting fractal. Another Conversation function painted the TOPn conversations across a sphere--not unique, but useful. Conversations also were tracked by protocol and sorted by address and number of octets within the Data List portion of Trouble Shooter.

Network-node availability is configured within TeVista with the Pinger Control application. It's as straightforward as it sounds--the definition of a response threshold and ping frequency with logging and alarming of the threshold violations. It lacks sophisticated triggers and event correlation, but for a simple, "Is it there?" or "Has it been there?," it works.

TeVista's packet-decode capability is below par--way below what protocol analyzers can do. In my tests, it showed Layer 2 and 3 headers with hex dumps of the rest of the packet. In one case the decode correctly identified SNMP packets but insisted that the packets were corrupt. Yet I knew there was nothing wrong with them. Packets can be output to a formatted text file, but not in a format readable by Network Associates' Sniffer, WildPackets' EtherPeek or any other common protocol analyzer.

Network Inventory Glitches

All the TeVista network-management applications are lame at creating an inventory of the network, but I was particularly disappointed that TeVista's Network Asset Manager, which automatically ping-sweeps subnets, registering IP, SNMP and Visibility agents, came up with shoddy results. First, only a single community string per scan is supported so, no matter what, multiple scans have to bombard the network. Even though our network has common devices from Cisco Systems, Extreme Networks, Hewlett-Packard, Nortel Networks, Juniper Networks and 3Com, none were correctly identified. I had to define all the devices manually.

Vendor Information TeVISTA 2.0 Network Monitoring and Asset Management Software, $14,995. Available: Now. Chevin, (866) 838-4782, (301) 816-0009; fax (301) 816-0231. www.chevin.com

Second, navigating discovered inventory was a joke and made me realize that this product would never work in a large environment. Nodes are displayed in a seemingly random flat order with no controls for reordering by any useful attribute, such as host name or IP address. The program should provide an explorer-like hierarchal display with groupings by device type, function and political or business function. In addition, placing devices in or removing them from the inventory into organizational groupings is very tedious. Each device had to be selected, right-clicked and deleted, and once in, can't be moved.

As the number of devices increases in the flat display, the icons become too small to read. This is a malady common to all network-management applications, but the better ones let you zoom on a portion of the screen or provide those hierarchal displays. One saving grace: TeVista does include pop-up information displays on mouse hovers.

I took exception to a statement made in Chevin's documentation that claimed the throughput of Ethernet is effectively 2 Mbps when a segment is running at 50 percent utilization. This is pure bunk: Nearly 100 percent utilization is possible in full-duplex situations, and buying more switches with more bandwidth is easier and cheaper than installing agents.

Data collection off the wire RMON or proprietary agents (like TeVista's Visibility Agent) are good for backbones or segments that aggregate server traffic. If this is your need, TeVista is worth considering. But as a general-purpose network-management application, there are better products available.