Network Bottleneck Symptoms

The simplest way to measure effective bandwidth is to determine the rate at which your server sends and receives data. Network bandwidth availability is a function of the organization's network infrastructure. Network capacity is a function of the network cards and interfaces configured on the servers.

Network Interface: Bytes Total/sec : To determine if your network connection is creating a bottleneck, compare the Network Interface: Bytes Total/sec counter to the total bandwidth of your network adapter card. To allow headroom for spikes in traffic, you should usually be using no more than 50 percent of capacity. If this number is very close to the capacity of the connection, and processor and memory use are moderate, then the connection may well be a problem.

Web Service: Maximum Connections and Web Service: Total Connection Attempts : If you are running other services on the computer that also use the network connection, you should monitor the Web Service: Maximum Connections and Web Service: Total Connection Attempts counters to see if your Web server can use as much of the connection as it needs. Remember to compare these numbers to memory and processor usage figures so that you can be sure that the connection is the problem, not one of the other components.

To determine the throughput and current activity on a server's network cards, you can check the following counters:

· Network\Bytes Received/sec
· Network\Bytes Sent/sec
· Network\Bytes Total/sec
· Network Current Bandwidth

If the total bytes per second value is more than 50 percent of the total capacity under average load conditions, your server might have problems under peak load conditions. You might want to ensure that operations that take a lot of network bandwidth, such as network backups, are performed on a separate interface card. Keep in mind that you should compare these values in conjunction with Physical Disk\% Disk Time and Processor\% Processor Time. If the disk time and processor time values are low but the network values are very high, there might be a capacity problem. Solve the problem by optimizing the network card settings or by adding an additional network card. Remember, planning is everything—it isn't always as simply as inserting a card and plugging it into the network.