Different Dimensions Of Qos; Packet Filtering - Symbol WS5000 Series System Reference Manual

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WS5000 Series Switch System Reference Guide

1.3.4.1 Different Dimensions of QoS

Different methods of QoS are applied for distinction between users and applications. The two main categories
are:
• QoS via Queuing – A network shared by different users such as in a revenue-based, shared office
building or a public hotspot is implemented with Service Level Agreements (SLA) based on how much
each group of users pay for bandwidth. In this case, one or all points of aggregation, such as the switch
and some high-end routers or policy managers, can allocate different percentages of the total
bandwidth to different groups of users through the use of queues. Bandwidth allocation can also be
further divided and applied to different applications again using Queues.
• Application QoS via Packet Marking – A network or a portion of the allocated bandwidth can be shared
by different applications. Voice communication (for example) can be more latency-sensitive or more
mission-critical than others. In this case, a priority is assigned to the traffic by adding the appropriate
QoS marking or tags to network traffic to provide higher precedence while the data is passed through
points of aggregation—routers, switch(es), and gateways—and the medium of transfer. Packet marking
provides configurable upstream devices and helps QoS end-to-end.

1.3.4.2 Packet Filtering

Packet filtering allows or discards packets matching certain criteria defined by Classification Groups (CG) on
an output packet port. Classification groups on an output port are defined with allow decisions, discard
decisions or a combination of both. A CG defined with an allow condition is associated with a priority number
in the range of 0 – 7, seven being the highest priority. shows the types of packet filtering that the WS5000
Series Switch supports.
Table 1.3 Packet Filters Supported
Packet filter Filters
MACsource Source MAC addresses.
MACdestination Destination MAC addresses.
ethertype Ethernet specifier: Speed.
vlanid Virtual LAN IDs
userpriority User Priority
protocol Protocol Type
tos Type of Service
IPsource Source IP
IPdestination Destination IP
sourceport Source Port
destinationport Destination Port.
MCMask Destination multicast group MAC address.