SD-WAN Classes Test

The Citrix SD-WAN configuration provides a default set of application-classification, rule-filtering, and class-assignment settings that can be applied to any virtual path service in the SD-WAN environment. Using classes, administrators classify a specific type of traffic on the virtual path. To handle the traffic over the virtual path, the classes are associated with the rules based on the current and expected traffic requirements. Each virtual path can have up to 17 (0-16) classes whereas each class is designated as Real-time, Interactive or Bulk. This, at a high level defines the overall priority of the class in terms of schedule time. By default:

• Real-time (RT) classes are used for VoIP or VoIP like applications, such as Skype or ICA audio. In general, we refer to voice only applications that use small UDP packets, that are business critical. Therefore. these classes are given the highest priority and gets up to 50% of the overall scheduler time. Each class can be weighted with respect to the other RT classes, for example, we could have two RT classes one that weighted to 70% and the other to 30%.
• Interactive (INT) classes are use for broadest category, and refer to any application that has a high degree of user interaction. Some of these applications, for example video conferencing, is sensitive to latency, and requires high bandwidth. Other applications like HTTPS, may need less bandwidth, but are critical to the business. The INT classes take the next priority to the RT classes and can consume the rest of the scheduler time as the traffic demands.
• Bulk (BLK) classes are used for high bandwidth traffic that can tolerate high latency. Applications that handle file transfer and need high bandwidth are categorized as bulk class. These applications involve very little human interference and are mostly handled by the systems themselves. The BLK classes take the lowest priority and can be considered scavenge classes. They can be weighted but they can be completely starved of bandwidth if the INT/RT traffic is consuming all of the scheduler time.

Administrators customize the classes and associate rules to have control over the traffic flow and also reduce manual workload when the network issue is reported. The efficiency of the classes can be measured by tracking the traffic handled by them. If any setbacks are detected in the traffic flow handled by any of the classes and are not addressed in time, data loss, delays and jitter may occur on the network. This in turn, may cause traffic congestion and slowness on the network and may lead to processing bottleneck. To avoid such anomalies, administrator should continuously monitor the data/packet transmission for each class configured on the Citrix SD-WAN appliance. This can be easily achieved using the SD-WAN Classes test.

This test auto-discovers the classes configured on the target Citrix SD-WAN appliance, and reports the type of each class. Additionally, this test reports the amount of data transmitted for each class, the amount of data that was pending and the amount of data dropped at regular intervals. In the process, this test also reveals the number of packets dropped during the transmission. Using the statistics reported by this test, administrators can find out how well the data/packet transmission handled using each class.

Target of the test : A Citrix SD-WAN

Agent deploying the test : A remote agent

Outputs of the test : One set of results for each class configured on the target SD-WAN appliance.

Configurable parameters for the test

Parameter	Description
Test Period	How often should the test be executed. By default, this is set to 5 minutes.
Host	The IP address of the target SD-WAN appliance for which this test is to be configured.
Port	Refers to the port at which the target SD-WAN listens to. By default, this will be NULL.
Timeout	Specify the time duration (in seconds) beyond which this test should time out in the Timeout text box. The default is 10 seconds.

Measurements made by the test

Measurement	Description	Measurement Unit	Interpretation
Class type	Indicates the type of this class.		The numeric values that correspond to each of the above-mentioned values are as follows: Measure Value Numeric Value Realtime 0 Interact 1 Bulk 3 Other 4 Note: By default, this measure reports one of the Measure Valuess listed in the table above to indicate the type of the class. The graph of this measure however, represents the same using the numeric equivalents alone.
Wait time	Indicates the time duration between transmitting packets for this class.	Seconds	A low value is desired for this measure. A sudden/consistent increase in the value of the measure is indicative of delay in packet transmission.
Data transmitted	Indicates the amount of data transmitted for this class during the last measurement period.	MB
Data pending to transmit	Indicates the amount of data to be transmitted for this class during the last measurement period.	MB
Data dropped	Indicates the amount of data dropped for this class during the last measurement period.	MB	Ideally, this value should be zero. A non-zero value of this measure indicates the data loss and traffic congestion on the network.
Packets transmitted	Indicates the number of packets transmitted for this class during the last measurement period.	Packets
Packets pending to transmit	Indicates the number of packets to be transmitted during the last measurement period.	Packets
Packets dropped	Indicates the number of packets dropped during the last measurement period.	Packets	Ideally, this value should be zero. A non-zero value of this measure may indicate the traffic congestion on the network.