User's Manual

46 ALFOplus 24GHz (North America) - Release 01.05.0x - MN.00395.E - 004
-P
max
=10
• Profile 2:
-S
min
= 20
-S
max
=40
-P
max
=10
These profiles can be set for the Yellow Frames (Y) and Green Frames (G) as well. These values represent:
•S
min
: represents the threshold after which the switch starts dropping packets
•S
man
and P
max
: are the thresholds that makes the curve of “Drop Percentage”/”Average Queue Oc-
cupation” change. After this point the dropping packets increase rapidly.
• “Red Gentle”: after the point represented by S
max
and P
max
: the Drop percentage can increase to
a 100% (RED) or can linearly increase. the choice of how to increase, directly or linearly to a 100%
is manage by disabling or enabling the RED Gentle.
7.3.5.1 Extended buffer capability on the radio queues
The SIAE switch has been provided with an extended buffer capability on the radio queues, which allows
to assign up to 128 Mbit (16MByte) to a single queue.
The following buffer configurations are available on the 8 output queues of the radio port:
• the length of each queue is configurable from 128kbit to 128Mbit
• radio port has a total available buffer of 184 Mbit (23 Mbyte), so the sum of all the queue lengths
of a single radio port does not have to exceed this value.
7.3.6 Scheduling methods
Once the priority is assigned, the traffic in the queues is then emptied by menas of either Strict Priority or
Weighted Fair Queue algorithms. With the Strict Priority the highest priority takes always precedence. With
WFQ the available bandwidth is shared between the different priorities with configurable weights. It is in
addition possible to configure at the same time some queues as Strict Priority and the remaining as WFQ.
Going into details:
• Strict Priority: first, all the packets from the highest priority queue are transmitted, then all the
packets from the second queue, and so on.
• Weighted Fair Queueing (W.F.Q.): the packets are sent on the radio following a rule based on the
weight assigned to each Queue.
Each queue “i” with WFQ is given a weight (importance) Wi.
WFQ guarantees a minimum service rate to queue “i”
Ri = R*Wi/(W1+W2+....+Wn) [Rate of the queue i]
Where:
R = rate of the servant (capacity available on the MW link)
W i= weight of the Queue taken in consideration
Wn = weight of the last Queue with WFQ enabled
This means that the rate of the queue is a fraction of the total bandwidth that depends
on the weight assigned to the Queue.
For example if the weights are set as Fig.15
.