How to configure Application Performance Analysis
Application Performance Analysis is an always-on feature, meaning that Observer is always collecting metadata about the performance of numerous applications on your network. It cannot be disabled, only configured.
Prerequisite(s):  
If you are unfamiliar with Application Performance Analysis, see Understanding Application Performance Analysis before beginning.
 
The "always-on" nature of Application Performance Analysis is when both Observer and the probe are both at 17.2.0.0 or later. In certain circumstances your Observer may not match the version of your probe. This table describes what happens in those situations.
Observer 17.2.0.0 and newer
Probe 17.2.0.0 and newer
Always on. Cannot be disabled.
Observer 17.1.1.4 and older
Probe 17.2.0.0 and newer
Probe collects and sends APA data to Observer even though the feature appears disabled in Observer.
Observer 17.2.0.0 and newer
Probe 17.1.1.4 and older
APA may be turned off. Since the probe collects the trending data and the probe does not have the new always-on functionality, therefore Observer can be configured to have the older probe honor the functionality it does have, which is the ability to turn APA on or off.
1. On the Home tab, in the Capture group, click Network Trending > Network Trending.
2. Click the Settings button. The Network Trending Settings window appears.
3. Click the Application Performance Analysis group tab.
4. Settings can be changed in each tab.
 
Figure 48: Configure your network trending settings here
 
 
 
General tab
The General tab allows you to set TCP retransmission settings and whether to track certain discovered servers.
 
Table 19. General tab
Setting
Description
Default selection or value
Track only servers using IP addresses with associated ports defined in “Protocol Definitions and Server Application Discovery”
Enable this setting to track only defined servers. See Discovering server applications on the network.
Disabled
Count rerouted as resent
Choose this if you want rerouted TCP transmissions to be considered resent, instead.
Disabled
Retransmission too fast
Set this value if necessary, but the default is appropriate in most cases. This value defines when a retransmission is too fast.
180 (ms)
Resent minimum time
Set this value if necessary, but the default is appropriate in most cases. This value defines the minimum amount of time needed for a resent to be considered such.
100 (ns)
 
Applications tab
The Applications tab allows you to configure TCP, UDP, and SCTP applications to monitor.
 
Table 20. Applications tab
Setting
Description
Default selection or value
Track servers using the following applications (tracking all applications when unchecked)
Allows APA to track servers using the protocols in the protocol list. Enabling this option allows changes to be made in this tab.
Enabled
Protocol (list)
When “Track servers using the following protocols” is enabled, the protocols in this list are tracked in APA.
N/A
Add button
Click the Add button to add an application protocol to the list of tracked servers.
N/A
Remove button
Remove an application protocol from the list by selecting one or more and clicking Remove. You can use SHIFT-click to select a range or CTRL-click to select multiple items.
N/A
 
Subnet Ranges tab
The Subnet Ranges tab allows you define on what subnets your application servers are located.
 
Table 21. Subnet Ranges tab
Setting
Description
Default selection or value
Limit tracked server connections to defined IP subnet ranges
Allows IP subnet ranges to be defined in this tab. This setting must be enabled for any settings in this tab to be active.
Disabled
Type
Choose the IP type of the target address range. Your options are IP (IPv4) or IPv6.
IP (IPv4)
Servers are located in this subnet
Enable this setting if servers are located in the leftmost subnet range (the subnet range on the left side of the arrow icon). If left disabled, all tracked server connections from this subnet are seen as clients.
Disabled
Filter traffic between two subnets
Enable this setting if you want to track server connections between two unique subnet ranges. If left disabled, server connections are tracked between one subnet and any others.
Disabled