Network Requirements

The network is rarely a bottleneck in most installations. However serious consideration must be given to it during the capacity planning stage. If the clients do not get adequate network bandwidth to send and receive messages from Oracle Internet Directory, the overall throughput will seem to be very low. For example, if we have configured Oracle Internet Directory to service 800 search operations every second, but the computer running the Oracle directory server is only accessible through a 10 Mbps network (10-Base-T switched ethernet), and we have only 60 percent of the bandwidth available, then the clients will only see a throughput of 600 search operations a second (assuming each search operation causes 1024 bytes to be transferred on the network). The following table shows the maximum possible throughput (in operations every second) for two types of operations (one requiring a transfer of 1024 bytes the other requiring a transfer of 2048 bytes) for two types of networks, 10 Mbps & 100 Mbps, at different rates of bandwidth availability:

Table 20-12  Maximum Possible Throughput for Two Types of Operations

Percent Available Bandwidth	Operations/sec 1024 bytes		Operations/sec 2048 bytes
	10 Mbps	100 Mbps	10 Mbps	100 Mbps
30	300	3000	150	1500
40	400	4000	200	2000
50	500	5000	250	2500
60	600	6000	300	3000
70	700	7000	350	3500
80	800	8000	400	4000
90	900	9000	450	4500

In some cases, it may also be important to consider the network latency of sending a message from a client to the Oracle directory server. In some WAN implementations, the network latencies may become as high as 500 milliseconds, which may cause the clients to time out for certain operations. In summary, given a range of networking options, the preferred choice should always be for highest bandwidth, lowest latency network.

Going back to the example of Acme Corporation, their peak usage rate is 936,000 lookups every hour which results in an equivalent number of lookup operations to the directory. This requires about 260 directory operations every second. Assuming that each operation results in a transfer of 2 KB of data on the network, this would imply that we should have a 100 Mbps network or at least 60 percent bandwidth available on a 10 Mbps network. Since the 100 Mbps network will typically have a lower latency, we will chose that over the 10 Mbps network.