Riverstone Networks WICT1-12 - Manual (Page 610)

30-6 Riverstone Networks RS Switch Router User Guide Release 8.0
Configuring WAN Interfaces WAN Configuration
levels of bandwidth allocated than less time-sensitive traffic such as file transfers or e-mail. Simply adding more and
more bandwidth to a network is not a viable solution to the problem. WAN access is extremely expensive, and there is
a limited (albeit huge) supply. Therefore, making the most effective use of existing bandwidth is now a more critical
issue than ever before.
The fact that IP communications to the desktop are clearly the most prevalent used today has made it the protocol of
choice for end-to-end audio, video, and data applications. This means that the challenge for network administrators
and developers has been to construct their networks to support these IP-based audio, video, and data applications along
with their tried-and-true circuit-based applications over a WAN.
In addition, these audio, video, and data traffic transmissions hardly ever flow at a steady rate. Some periods will see
relatively low levels of traffic, and others will temporarily surpass a firm’s contracted Committed Information Rate
(CIR). Carrier-based packet-switched networks such as Frame Relay and ATM are designed to handle these temporary
peaks in traffic, but it is more cost- and resource- efficient to employ effective QoS configuration(s), thus relaxing the
potential need to up your firm’s CIR. By applying some of the following sorts of attributes to interfaces on your
network, you can begin to shape your network’s QoS configuration to use existing bandwidth more effectively.
Source Filtering and ACLs
Source filtering and ACLs can be applied to a WAN interface. However, they affect the entire module, not an individual
port.
For example, if you want to apply a source MAC address filter to a WAN serial card located in slot 5, port 2, your
configuration command line would look like the following:
Port se.5 is specified instead of se.5.2 because source filters affect the entire WAN module. Hence, in this example,
source-mac 000102:030405
would be filtered from ports se.5.1, se.5.2, se.5.3, and se.5.4 (assuming that you are
using a four-port serial card).
ACLs work in a similar fashion. For example, if you define an ACL to deny all http traffic on one of the WAN
interfaces, it will apply to the other WAN interfaces on that module as well. In practice, by making your ACLs more
specific, for example by specifying source and destination IP addresses with appropriate subnet masks, you can
achieve your intended level of control.
Weighted-Fair Queueing
Through the use of Weighted-Fair Queueing QoS policies, WAN packets with the highest priority can be allotted a
sizable percentage of the available bandwidth and “whisked through” WAN interface(s). Meanwhile, the remaining
bandwidth is distributed for “lower-priority” WAN packets according to the user’s percentage-of-bandwidth
specifications. Refer to the Riverstone RS Switch Router Command Line Interface Reference Manual for more detailed
configuration information.
Note Weighted-Fair Queueing applies only to best-effort traffic on the WAN card. If
you apply any of the WAN specific traffic shaping commands, then weighted fair
queuing will no longer be applicable.
rs(config)# filters add address-filter name wan1 source-mac 000102:030405 vlan 2
in-port-list se.5