Cisco CiscoWork QoS Policy Manager 4.1.2 User Guide
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User Guide for QoS Policy Manager 3.0
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Chapter 2 Planning for Quality of Service
What Types of Quality of Service Does QPM Handle?
First In, First Out (FIFO) Queuing: Basic Store and Forward on Routers
First In, First Out (FIFO) queuing is the basic queuing technique. In FIFO
queuing, packets are queued on a first come, first served basis: if packet A arrives
at the interface before packet B, packet A leaves the interface before packet B.
This is true even if packet B has a higher IP precedence than packet A since FIFO
queuing ignores packet characteristics.
queuing, packets are queued on a first come, first served basis: if packet A arrives
at the interface before packet B, packet A leaves the interface before packet B.
This is true even if packet B has a higher IP precedence than packet A since FIFO
queuing ignores packet characteristics.
FIFO queuing works well on uncongested high-capacity interfaces that have
minimal delay, or when you do not want to differentiate services for packets
traveling through the device.
minimal delay, or when you do not want to differentiate services for packets
traveling through the device.
The disadvantage of FIFO queuing is that when a station starts a file transfer, it
can consume all the bandwidth of a link to the detriment of interactive sessions.
This phenomenon is referred to as a packet train because one source sends a
“train” of packets to its destination and packets from other stations get caught
behind the train.
can consume all the bandwidth of a link to the detriment of interactive sessions.
This phenomenon is referred to as a packet train because one source sends a
“train” of packets to its destination and packets from other stations get caught
behind the train.
You do not need to define any queuing parameters for FIFO queuing.
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