Riverstone Networks WICT1-12 - Manual (Page 622)

30-18 Riverstone Networks RS Switch Router User Guide Release 8.0
WAN Rate Shaping WAN Configuration
Note If Be is defined in a rate shaping template, a good rule of thumb is to set its value
roughly equal to Bc / 2.
Use the
wan apply
command to apply the template to a WAN port. Specify Ethernet flows within the
wan apply
command using one of the following identifiers:
Destination IP address Any Ethernet flow attempting to reach this destination IP address is rate shaped according
to the template.
Source IP address Any Ethernet flow with this source IP address is rate shaped according to the template.
Port number Any Ethernet flow originating from this physical port is rate shaped according to the
template.
VLAN name Any Ethernet flow that is a member of this VLAN is rate shaped according to the template.
In the example below, the previously defined WAN rate shaping template (WanTemp1) is applied to a Clear Channel
T3 WAN port, and the Ethernet flows to be rate shaped are identified by a source IP address:
In the example above, notice that a subnet mask is specified with the source IP address. Adding the subnet mask causes
the rate shaping template to be applied to all flows from the subnet 134.141.153.0. To apply rate shaping to a single
source IP address, enter the IP address only, but do not specify a subnet mask.
The
wan apply
command also allows you to set the following parameters that affect rate shaping behavior:
burst-queue-depth The depth (in packets) of the queue used to buffer packets when Bc or Bc + Be are
exceeded.
no-shape-high-priority Specifies that Ethernet traffic from the high-priority queue does not take part in rate shaping
and transmits on the WAN port without bandwidth restrictions.
shape-control-priority Normally, control-priority traffic (ARP, OSPF, and so on) are not subjected to rate shaping.
However, control-priority traffic is included in the rate shaping process if this parameter is
specified.
Note Rate shaping control-priority traffic is not recommended.
30.13.2 The WAN Rate Shaping Algorithm
The first step in rate shaping traffic through a WAN port is to allot some percentage of the WAN port’s bandwidth (in
Kbps) to each Ethernet flow. This allotted bandwidth is called the Committed Information Rate (CIR). Generally, the
total of the CIRs for all rate shaped flows should not exceed the total bandwidth of the WAN port. However, depending
on the characteristics of each flow, some oversubscribing of WAN port bandwidth is usually permissible.
rs(config)# wan apply rate-shape-parameters WanTemp1 port t3.3.1 source-ip-address
134.141.153.0/24