PLANET WGSW-5242 - Manual (Page 114)

User’s Manual of WGSW-5242
114
4.8.2 Queue Settings
The Queue Setting page contains fields for defining the QoS queue forwarding types. The screen in Figure 4-8-1 appears.
Figure 4-8-1
Queue Settings screenshot
The page includes the following fields:
Object Description
• Scheduling Mode There are two available schedule mode:
• Strict Priority: the packets in the higher queue will always be served first until the
queue is empty.
• Weighted Round Robin: the packets will be served according to the queue weight.
• Queue Indicates priority queues.
Queue 1
is the lowest priority queue, and Queue 4 is the highest priority queue.
• Weight Indicates the weight (number of packets) to be served in the queue before moving to
serve next queue. A high priority queue should have a higher weight than a low priority
queue.
4.8.3 DSCP
TOS/DSCP priority is obtained through a 6-bit Type-of-Service (TOS) or Differentiated Service Code Point (DSCP) to 3-bit
priority mapping.
The Type of Service (TOS) octet in the IPv4 header is divided into three parts; Precedence (3 bits), TOS (4 bits), and MBZ (1
bit). The Precedence bits indicate the importance of a packet, whereas the TOS bits indicate how the network should make
tradeoffs between throughput, delay, reliability, and cost (as defined in RFC 1394). The MBZ bit (for “must be zero”) is currently
unused and is either set to zero or just ignored.