OmniSwitch os6900 User Manual

Configuring QoS Traffic Policing and Shaping
OmniSwitch AOS Release 7 Network Configuration Guide June 2013 page 25-27
Port Groups and Maximum Bandwidth
If a port group condition (see “Creating Port Groups” on page 25-58) is used in a maximum bandwidth
policy, the bandwidth value specified is shared across all ports in the group.This also applies to flows that
involve more than one port. For example, if a policy specifies a maximum bandwidth value of 10M for a
port group containing 4 ports, the total bandwidth limit enforced is 10M for all 4 ports.
Note the following when configuring ingress maximum bandwidth policies:
• If a policy condition applies to ports that are located on different slots, the maximum bandwidth limit
specified is multiplied by the number of slots involved. For example, if a rule is configured to apply a
maximum bandwidth limit of 10M to ports 1/1, 3/10, and 4/5, then the actual bandwidth limit enforced
for all three ports is 30M.
• The maximum traffic received by a destination port is also dependant on how many slots are sending
traffic to the destination port. However, each slot is restricted to sending only 10k.
• If a policy condition applies to ports that are all on the same slot, then the maximum bandwidth value
specified in the rule is not increased.
• Ingress bandwidth limiting is done using a granularity of 64K bps.
• The show active policy rule command displays the number of packets that were dropped because they
exceeded the ingress bandwidth limit applied by a maximum bandwidth policy.
• Although bandwidth policies are applied to ingress ports, it is possible to specify a destination port or
destination port group in a bandwidth policy as well. Doing so, effects egress rate limiting/egress
policing on the ingress port itself. The limitation of bridged port traffic only on OmniSwitch 10K desti-
nation ports applies in this case as well.
The following subsections provide examples of ingress maximum bandwidth policies using both source
and destination port groups.
Example 1: Source Port Group
In the following example, a port group (pgroup) is created with two ports and attached to a policy condi-
tion (Ports). A policy action with maximum bandwidth is created (MaxBw). The policy condition and
policy action are combined in a policy rule called PortRule.
-> policy port group pgroup 1/1-2
-> policy condition Ports source port group pgroup
-> policy action MaxBw maximum bandwidth 10k
-> policy rule PortRule condition Ports action MaxBw
In this example, if both ports 1 and 2 are active ports, the 10000 bps maximum bandwidth is shared by
both ports. In other words, maximum bandwidth policies for port groups define a maximum bandwidth
value that is a total bandwidth amount for all ports, not an amount for each port.
Example 2: Destination Port Group
In the following example, a port group (pgroup2) is created with several ports and attached to a policy
condition (Ports2). A policy action with maximum bandwidth is created (MaxBw). The policy condition
and policy action are combined in a policy rule called PortRule2.
-> policy port group pgroup2 1/1 1/25 2/1
-> policy condition Ports2 destination port group pgroup2
-> policy action MaxBw maximum bandwidth 10k
-> policy rule PortRule2 condition Ports2 action MaxBw

OmniSwitch os6900 Specifications

General

Brand	OmniSwitch
Model	os6900
Category	Switch
Language	English