Planning 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:
a. Choose
Monitor > Monitoring Policies
and
c
reate an Interface Health template.
b. Choose
Inventory > Grouping > Port
, select the interfaces and click
Add to Group
, then select
WAN Interfaces
as the group.
Step 1 Choose
Dashboard > General
.
Step 2 To view the usage statistics for the WAN interfaces on the routers connecting remote branches to the WAN, choose
Dashboards > Network Interface
and if it is not already there, add
the
Top N WAN Interfaces by Utilization
dashlet (see
Adding Dashlets
in the
Cisco Prime Infrastructure 2.2 User Guide
).
For each interface, this dashlet shows the site, the IP of the device hosting the WAN interface, the interface name, maximums and average utilization, and the utilization trend line for the past 24 hours.
Step 3 To see the utilization statistics for the past month, set the
Time Frame
on the
Filters
line to
Past 4 Weeks
.
Step 4 Find the WAN interface for the branch to which you are adding users. In the
Interface
column, click the interface’s name to display that interface’s dashboard. The interface dashboard shows the following for this single interface:
-
Interface Details
-
Top Applications by Volume
-
Number of Users Over Time
-
Class Map Statistics
-
Interface Tx and Rx Utilization
-
Top N Clients (In and Out)
-
DSCP Classification
-
Top Application Traffic Over Time
Step 5 Concentrate on
Top Application Traffic Over Time
, which gives a color-coded map of the top ten applications with the heaviest traffic over this interface.
Step 6 To get a better idea of the longer-term performance trend, click the
Clock
icon next to the 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 7 For a quick report of the same data as the interface dashboard, 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
.
Table 15-1
shows the ISP profile used to test against (it is very similar to the Caida.org Internet profile).
Table 15-1 Internet Profile - Traffic Profile per 1Gbps
|
|
|
|
|
|
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
|