2 packet flow, Illustration, Packet flow – RCA THOMSON SpeedTouchTM (Wireless) Business DSL Router User Manual

Page 76: Chapter 6, Meters, queues and ipqos, Classification metering

Advertising
background image

Chapter 6

Meters, queues and IPQoS

E-NIT-CTC-20041213-0013 v0.5

74

6.4.2 Packet flow

Illustration

The figure below illustrates the packet flow in case label based metering is used.

Stage

Description

1

A packet arrives in the resource management module and gets
classified based upon a rule set. The packet gets a label assigned.
In case the label refers to a meter the packet gets forwarded to the
meter module. If not, the packet is forwarded back to the LAN or to
the WAN after queuing and scheduling.

2

Packets in excess of the drop rate will be dropped or counted
depending on the settings of the dropaction parameter.

3

If the mark rate is exceeded the packet will be marked or counted
depending on the settings of the markaction parameter. If a packet is
marked, the tos byte can be set or the internal class can be changed.
If classification has been enabled the internal class will be set.

4

The class is set. This will place packets in a specified queue.

5

Based upon the destination (LAN/WAN) the packet gets forwarded to
the proper interface.

6

In case the packet will be sent out to the WAN side, the packet gets
assigned to the corresponding queue.

7

Finally the ATMQoS parameters are taken into account and the
packet is ready to be sent to the WAN.

Packet

Data

Meter

Classification

Meter

Drop

Packet is

dropped

Mark

Tos marking

Set tos byte

Classification

Set Class

Action

Action

Queue

scheduling

Map class to

queue

ATM QoS

1

2

3

4

5

6

Drop

Count

Count

Mark

yes

no

no

no

yes

yes

yes

no

no

yes

LAN

7

WAN

Classification

Metering

Advertising