Congestion Management Technique Comparison - HP FlexNetwork MSR Series Configuration Manuals

Figure 20 RTPQ
Packets to be sent

Congestion management technique comparison

Congestion management techniques offer different QoS capabilities to meet different application
requirements, as explained in
Table 3 Congestion management technique comparison
Type
FIFO
PQ
CQ
RTP queue
Other queuing
Classify
mechanisms: PQ,
CQ, and WFQ
Table
Number of
Advantages
queues
•
1
•
Provides strict priority service
for mission-critical applications
4 and guarantees low delay for
real-time traffic, such as voice
traffic.
•
•
16
Dequeued
first
Schedule
3.
No need to configure,
easy to use.
Easy to operate,
delay.
Bandwidth assignment in
percentages for different
applications.
Bandwidth reassignment
to increase bandwidth for
each class when packets
of certain classes are not
present.
63
Packets sent
Interface
Sending
queue
Disadvantages
•
All packets are treated equally.
The available bandwidth, delay
and drop
determined by the arrival order
of packets.
•
No restriction on traffic from
connectionless
(protocols without any flow
control mechanism, UDP, for
low
example). This problem results
in bandwidth loss for traffic of
connection-oriented protocols
(TCP, for example).
•
No delay
time-sensitive
applications, such as VoIP.
•
Need to
processing speed.
•
If packets always exist in
high-priority queues, packets in
low-priority queues cannot be
sent.
Need to configure, low processing
speed.
probability are
protocols
guarantee for
real-time
configure, low