RCA THOMSON SpeedTouchTM (Wireless) Business DSL Router - Manual (Page 80)

Chapter 6
Meters, queues and IPQoS
E-NIT-CTC-20041213-0013 v0.5
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Maxpackets
As we will see further on there is a
maxpackets
parameter in the IPQoS settings
which sets the max number of packets that can be placed in all queues (0..5) at one
time. If the maxpackets parameter for each seperate queue is set to 100 this would
mean that the maximum number of packets in that queue would be 100. If this is set
for the 5 queues this would mean that a total of 500 packets could be placed in the
queues.
The
maxpackets value can not be more than 250, so we could never place 500
packets in the queues. For example:
 The total size for queuing is 250 packets.(IP QoS maxpackets)
 Each of the 6 queues can hold a maximum of 100 packets. (queue maxpackets)
 Each of the 6 queues has 13 packets reserved incase they are empty. (queue
respackets)
 The rest of the total size (250-(6*13)) will be used by means of priority.
If 100 packets are placed in the EF queue this would leave us with 98 packets that
can still be placed in an other queue.
250 (maxpackets) -100 (EF queue)=150
150 - (5*13respackets)=85 packets that can be place in a queue
The total number of packets that can still be placed in 1 queue will now be
85+13=98
100(EF)+98+(4*13)=250
This is used to avoid queue starvation. If no reserved packets would be defined, one
queue could use up all availlable queue space.
Maxbytes
Respackets
maxpackets value Description
number (0..255) The maximum number of packets in the subqueue.
maxbytes value Description
number (0..64) The maximum size in kilo bytes (KB) of the subqueue.
respackets value Description
number (0..250) The reserved number of packets in the subqueue. This
is the space reserved in the subqueue to allow
packets.