Speedtouch IPQoS, Configuration Manual

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Chapter 4
IP QoS Framework Overview
E-NIT-CTC-20041213-0013 v0.5
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4.2 Resource Management
Introduction
The RM module reserves memory for four independent traffic classes. Resources are
reserved for each RM-class, both in the upstream and in the downstream direction (8
reservations in total). The figure below shows the Resource Management
reservations.
For incoming data towards the IP host, this module copies the VLAN user priority
field into the packet internal class indication. The module also sets (or raises) the
internal class indication based upon the ATM VP/VC QoS category for reassembled
frames.
As a result, incoming low priority UBR (Unspecified Bit Rate) traffic will not be able to
consume all resources because resources are reserved for VBR (Variable Bit Rate)
and CBR (Constant Bit Rate) data. Similarly, low priority VLAN frames won't be able
to consume all resources because resources are reserved for high priority (based
upon the VLAN user priority field) VLAN frames.
resource
reservation
0 1 2 3
UPSTREAM
0 1 2 3
DOWNSTREAM
Dynamic Memory Pool