Allied Telesis AT-S63 - Manual (Page 113)

AT-S63 Management Software Features Guide
Section II: Advanced Operations 113
Classifier Criteria
The components of a classifier are defined in the following subsections.
Destination MAC Address (Layer 2)
Source MAC Address (Layer 2)
You can identify a traffic flow by specifying a source and/or destination
MAC address. For instance, you might create a classifier for a traffic flow
destined to a particular destination node, or from a specific source node to
a specific destination node, all identified by their MAC addresses.
The management software does not support a classifier based on a range
of MAC addresses. Different MAC addresses must be considered
separate traffic flows, with their own classifiers.
Ethernet 802.2 and Ethernet II Frame Types (Layer 2)
You can create a classifier that filters packets based on Ethernet frame
type and whether a packet is tagged or untagged within a frame type. (A
tagged Ethernet frame contains within it a field that specifies the ID
number of the VLAN to which the frame belongs. Untagged packets lack
this field.) Options are:
ˆ Ethernet II tagged packets
ˆ Ethernet II untagged packets
ˆ Ethernet 802.2 tagged packets
ˆ Ethernet 802.2 untagged packets
802.1p Priority Level (Layer 2)
A tagged Ethernet frame, as explained in “Tagged VLAN Overview” on
page 257, contains within it a field that specifies its VLAN membership.
Such frames also contain a user priority level used by the switch to
determine the Quality of Service to apply to the frame and which egress
queue on the egress port a packet should be stored in. The three bit binary
number represents eight priority levels, 0 to 7, with 0 the lowest priority
and 7 the highest. Figure 4 illustrates the location of the user priority field
within an Ethernet frame.