Performance Monitor and Networks

I discussed Windows NT Performance Monitor basics in "The Windows NT Performance Monitor," March 1997, and "More Windows NT Performance Monitor," April 1997. You can download these articles from the Windows NT Magazine Web site (http://www.winntmag.com). In this article, I'll discuss how you can use Performance Monitor to analyze and optimize your network, and I'll show you how Performance Monitor can help you troubleshoot your network.

After you open a Performance Monitor session, you need to add the counters to track network activity. Performance Monitor adds counters as you add software components to your system. The more network protocols and services you install, the more counters Performance Monitor uses. I'll discuss the NetBEUI, TCP/IP, Network Interface, Network Segment, and Server counters.

NetBEUI
If you're running NetBEUI, you can add several counters. Screen 1, page 220, shows how to add the NetBEUI and NetBEUI Resource counters.

The NetBEUI counter. The NetBEUI object measures network performance. You might have multiple instances of this object, as Screen 2, page 220, shows. For example, if the NetBEUI protocol is bound to the network card and your dial-up adapter, you'll have more than one instance. The default NetBEUI counter is Bytes Total/sec. This counter measures the total bytes your computer sends and receives on the NetBEUI protocol. It measures the data bytes but not the related control information.

When you optimize your network, you need to consider the type of network traffic. All network traffic travels as frames. You can classify network frames as datagram traffic or session traffic. Datagrams are packets whose delivery to a remote computer isn't acknowledged or guaranteed. The network typically uses a datagram when the browser service calls an election to name a computer as Master Browser. The logon process and name resolution (finding the network address that goes with a computer name) also use datagrams. The network generates a session to guarantee error-free data transfer over an established connection. The total bytes transmitted and received can be broken down into Datagram Bytes and Frame Bytes. The Frame Bytes counter includes datagram and session traffic.

The NetBEUI Resource counter. The NetBEUI Resource counter shows NetBEUI system resource use. You can monitor the Times Exhausted counter to identify network problems. This counter shows the number of times the system used network resource buffers. In the Times Exhausted counter, you can monitor the instances of Links, Connections, Addresses, and Address Files. These counters are cumulative. Increasing values tell you the system is approaching its resource limit. You must modify your Registry settings to correct this problem. (For information about modifying Registry settings, see Paula Sharick, "Registry Secrets," October 1995; Christa Anderson, "Care and Feeding of the Registry," December 1996; and Mark Russinovich, "Inside the Windows NT Registry," April 1997.)

Other counters. Additional NetBEUI counters include Frames Rejected/sec, Failures Adapter, and Failures Resource Local. The Frames Rejected/sec counter tallies frames that the computer rejected because of errors and that must be resent. The ratio of Frames Rejected to Frames Received should be fairly low, but the number of frames rejected might not be zero, because network collisions can necessitate resending. The Failures Adapter counter shows the number of dropped connections because of an adapter failure (you want the count to be zero). This cumulative counter shows the total since the Performance Monitor session started. You wouldn't routinely monitor this counter, but it's useful for checking network card malfunction. On a server, the Failures Resource Local counter shows the number of attempted connections that have failed because of the local computer's low resource availability. This cumulative counter displays zero unless the server can't handle the system's demands.

TCP/IP
TCP/IP has an odd feature: Even if you have TCP/IP installed, you must load the Simple Network Management Protocol (SNMP) Service to see the TCP/IP counters. Go to Control Panel, Network. Select the Services tab, and add the SNMP Service, as Screen 3 shows. You must then restart your computer.

After your restart your computer, you'll see several new counters, including TCP, IP, Network Interface, Internet Control Message Protocol (ICMP), and User Datagram Protocol (UDP). When you load the SNMP Service, your system installs essential DLLs that enable the counters.

SNMP supplies network-management information, but you don't need the service unless your organization is running third-party SNMP management software, such as HP OpenView. If you don't need SNMP, remove it to save resources. The TCP/IP counters remain when you remove the SNMP Service.

   Previous  [1]  2  Next