As we’ve said, if your serial links are not congested, you do not need to implement queuing.
However, if the load exceeds the transmission rate for small periods of time, you can use a Cisco
IOS queuing option to help the congestion on a serial link.
To effectively configure queuing on a serial link, you must understand the types of queuing
available. If you choose the wrong type of queuing, you can do more harm on the link than help.
Also, this is not a one-time analysis of traffic patterns. You must constantly repeat your analysis
of your serial link congestion to make sure you have implemented the queuing strategy correctly.
Figure 30.2 shows the queuing options available from Cisco.
FIGURE 3 0 . 2
Queuing options
The following steps and Figure 30.2 describe the analysis you should make when deciding on
a queuing policy:
1.
Determine whether the WAN is congested.
2.
Decide whether strict control over traffic prioritization is necessary and whether automatic
configuration is acceptable.
3.
Establish a queuing policy.
4.
Determine whether any of the traffic types you identified in your traffic pattern analysis can
tolerate a delay.