3com 3C319 Manuale Utente
Using Class of Service Advanced Options
7-7
Class of Service Advanced Options Settings
This section provides a detailed description of each
Advanced Values field shown on the Class of Service
Advanced Options screen (
Advanced Values field shown on the Class of Service
Advanced Options screen (
).
The Advanced Options section of the Class of Service
Advanced Options Screen shown in lower part of
Advanced Options Screen shown in lower part of
is not currently available for token ring
installations.
FIFO Packet Threshold
This setting controls the number of non–Class of Service
packets the network driver will allow in the FIFO ahead
of any Class of Service packets. A smaller number
decreases the time between Class of Service packets
but can adversely affect performance. A value of 12
is recommended.
packets the network driver will allow in the FIFO ahead
of any Class of Service packets. A smaller number
decreases the time between Class of Service packets
but can adversely affect performance. A value of 12
is recommended.
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.
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 two (2, 4, 8) but the
optimal value may vary depending on the PC and
application.
applications use three UDP streams for the video data.
The value must be a power of two (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.
may only want to conference with four other people at
a time.
A value of 16 is recommended 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.
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.