No other factor matters more to the way a user perceives your server’s performance than the network that connects your server to the user’s computer. The delay, or latency, between when a request is made and the time it’s received can make all the difference. A high degree of latency means that it doesn’t matter if you have the fastest server on the planet: The user experiences a delay and perceives that your servers are slow.
Generally speaking, the latency that the user experiences is beyond your control. It’s a function of the type of connection the user has and the route the request takes to your server. The total capacity of your server to handle requests and the amount of bandwidth available to your servers are factors under your control, however. Network bandwidth availability is a function of your organization’s network infrastructure.
Network capacity is a function of the network cards and interfaces configured on the servers. The capacity of your network card can be a limiting factor in some instances. Most servers use 10/100 network cards, which can be configured in many ways. Someone might have configured a card for 10 Mbps, or the card might be configured for half duplex instead of full duplex. If you suspect a capacity problem with a network card, you should always check the configuration.
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 PhysicalDisk\% Disk Time and Processor\% Processor Time. If the disk time and processor time values are low but the network values are very high, you might have a capacity problem. Solve the problem by optimizing the network card settings or by adding a network card. Remember, planning is everything—it isn’t always as simple as inserting a card and plugging it into the network.