How to Plan the Network Capacity Changes
Cisco Prime Infrastructure with Assurance allows you to view and report a variety of key performance indicators that are critical for maintaining and improving your network’s operational readiness and performance quality. This information is especially critical in adapting to ever increasing network loads.
 Note |
To use the features described in this chapter, your Prime Infrastructure implementation must include Assurance licenses. These features are supported on ASR platforms only. |
In the following workflow, we take the role of a network administrator who has just been told that a large staff expansion is planned for a branch office. This change will add more users to the branch LAN, many of whom will be using WAN applications. We want to monitor the branch’s key interfaces for usage and traffic congestion, so we can see if more users on the branch LAN will mean degraded WAN application performance for those users. To be certain we have an adequate picture, we will need to look at both short- and long-term performance trends for all the WAN applications the branch uses.
Before You Begin
- Set up the
Top N
WAN Interfaces by Utilization dashlet:
-
Choose Monitor > Monitoring Policies and create an Interface Health template.
-
Choose Inventory > Group Management > Port Groups, select the interfaces and click Add to Group, then select WAN Interfaces as the group.
-
- Enable SNMP polling.
Procedure
| Step 1 |
Choose Dashboard > Overview > General. |
| Step 2 |
To view the usage statistics for the WAN interfaces on the routers connecting remote branches to the WAN, choose Network Interface |
| Step 3 |
If it is not already there, add the Top N Interface Utilization dashlet. For each interface, this dashlet shows the Device Name and IP of the device hosting the WAN interface, the interface name and speed, and Transmit/Receive maximum, average and last-polled utilization. |
| Step 4 |
To see the utilization statistics for the past month, click the Clock icon next to the Top N Interface Utilization dashlet title to change the Time Frame on the Filters line to Past 4 Weeks. |
| Step 5 |
In the Top N Interface Utilization dashlet, find the WAN interface for the branch to which you are adding users. |
| Step 6 |
In the Interface column, click the interface’s name to display the Dashboard > Performance > Interface page for that interface. The page shows the following dashlets for this single interface:
|
| Step 7 |
Concentrate on the Top Application Traffic Over Time dashlet on this page. This dashlet gives a color-coded map of the top ten applications with the heaviest traffic over this interface. |
| Step 8 |
To get a better idea of the longer-term performance trend, click the Clock icon next to the Top Application Traffic Over Tim dashlet title to change the Time Frame to Past 24 Hours, Past 4 Weeks, or Past 6 Months. To zoom in on particular spikes in the graph, use the Pan and Zoom handles in the lower graph. |
| Step 9 |
For a quick report of the same data as the interface page, choose Reports > Report Launch Pad. Then choose Performance > Interface Summary. Specify filter and other criteria for the report, select the same interface in Report Criteria, then click Run. |
What to do next
The following table shows the ISP profile used to test against (it is very similar to the Caida.org Internet profile).
|
TCP |
UDP |
HTTP |
RTP |
Total |
|
|---|---|---|---|---|---|
|
Connection Rate (flows per second) |
5,000 |
5,000 |
800 |
10 |
10,000 |
|
Concurrent Flows |
150,000 |
150,000 |
50,000 |
300 |
300,000 |
|
Packet Rate |
150,000 |
40,000 |
50,000 |
15,000 |
199,000 |
|
Related Bandwidth (bps) |
900Mbps |
100Mbps |
295Mbps |
25Mbps |
1GBps |
|
Packet Size (derived) |
750 |
313 |
738 |
208 |
658 |
|
Number of Parallel Active Users |
60,000 |
Derived from the number of flows |
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