HP Network Direr Software Products manual Network Topology

626CHAPTER 15: PRIORITIZING NETWORK TRAFFIC

As these standards each define a single field in which to store the marking, it means that simple classification devices can still be used as part of a network-wide traffic prioritization solution provided that the following conditions are met:

■Simple classification devices must be able to classify on the user priority field, the DiffServ field or both.

■Complex classification devices must be able to mark packets appropriately based upon their traffic type. This must be done using a marking mechanism that the simple classification devices are able to classify. Whilst it is possible to use different marking schemes at different locations in the network 3Com recommends that, if possible, one is selected and used throughout the network.

■Packets sent across the network must first pass through a complex classification device (such as a 3Com SuperStack 3 Switch 4400) so that they can be marked appropriately. This enables simple classification devices to prioritize packets.

For traffic prioritization to work on an end-to-end basis in your network it is recommended that you structure your network as shown in Figure 343.

Figure 343 Network Topology

	Boundary Nodes
Device Capable of		Device Capable of
Complex Classification		Complex Classification

	k
in
L
N
A
W

Interior Nodes

Device Capable of	Device Capable of
Complex Classification	Complex Classification