3Com TokenLink VelocityTM XL PCI Network Interface Card manual Configuring Class of Service

Configuring Class of Service 4-27

Concurrent UDP Streams This option controls the number of simultaneous multimedia UDP packet streams the network driver can handle at any time. For many applications, the number of UDP streams is the same as the number of connections.

For example, for videoconferencing with three people, applications use three UDP streams for the video data. The value must be a power of 2 (2, 4, 8) but the optimal value may vary depending on the PC and application.

A video server may support 32 connections, but a client may only want to conference with four other people at a time.

The default value of 16 is the recommended setting for most applications.

Low-Priority Ratio When Class of Service support is enabled, high-priority packets are always transmitted before low-priority packets. If a certain high-priority application sends out enough packets, no low-priority packets may be sent.

To prevent this problem, the driver uses a ratio value to periodically send out a low-priority packet (if one is waiting to be sent).

For example, if a value of 1000 is entered, one low-priority packet would be sent for every 1000 high-priority packets. The default value of 25 is the recommended setting for most applications.

Natural Packet Interval This field is not applicable. Any value entered in this field is ignored.

Disable Switch Packet Prioritization This option is not currently enabled. Any setting is ignored.

Disable Receive Packet Buffering This option is not currently enabled. Any setting is ignored.