Contemporary Control Systems Compact Managed Switches Software Manual for Web Browser - Manual (Page 36)

TD020851-0MG
36
4.4.7.3 Configure TOS/DiffServ Priority
When configuring the TOS/DiffServ priority, a detailed screen of three tables appears.
Each table — upper, middle and lower — is discussed and illustrated individually in turn.
At the bottom of the screen there are two links to the other types of QoS.
Upper Table — Configure TOS/DiffServ Priority
The user must first decide which service to be used: TOS or DiffServ. This choice is
made in the top-right portion of the upper table shown in the default screen of Figure 31
which displays a screen for an 8-port model. Screens for 16- and 24-port models
function the same — but simply display more ports.
The IP header contains an eight-bit field originally known as the
Type of Service (TOS)
field — but TOS priority had little acceptance. Subsequently, these eight bits were
redefined to become the more popular Differentiated Services (DiffServ) field.
Regardless of the type of QoS chosen, each port (disabled by default) must be
individually enabled to establish its QoS service.
After the choice of service has been made and the port behaviours determined, these
parameters must be registered by clicking the “Apply” button immediately below the
table before editing the other tables or leaving this screen or refreshing this screen.
Otherwise, the upper-table settings will be lost.
Figure 31 — Configure TOS/DiffServ Priority for an 8-port Switch