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 > Group Management > Port Groups
, select the interfaces and click
Add to Group
, then select
WAN Interfaces
as the group.
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:
-
Interface Details
-
Interface Tx and Rx Utilization
-
Top N Applications
-
Top N Clients
-
Number of Clients Over Time
-
DSCP Classification
-
QoS Class Map Statistics
-
oS Class Map Statistics Trend
-
Top Application Traffic Over Time
Step 7
C
oncentrate 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
.
The following table 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
|