CBR Level Service Class Test

Service classes are user-defined groups of IP addresses and port numbers that allow the Branch Repeater to accelerate or not accelerate a particular group of connections or a single connection.

Once a service class is created, acceleration (also known as flow control) and compression can be enabled or disabled for that particular service class.

Post service class configuration, it is good practice to observe the accelerated traffic to and from each service class, so that you can check the effectiveness of the acceleration/compression rules that you have set per service class. This is where the CBR Level Service Class test helps. This test auto-discovers the service classes configured in the branch repeater, monitors the volume of traffic sent and received by each service class, captures packet drops that occur when QoS thresholds are violated by a service class, and enables administrators to determine the following:

How well the branch repeater accelerates/compresses traffic to/from service classes;
Service classes for which acceleration/compression rules may have to be fine-tuned

Target of the test : A Citrix Branch Repeater

Agent deploying the test : An external agent

Outputs of the test : One set of results for each service class configured in the Citrix Branch Repeater being monitored.

Configurable parameters for the test
Parameter	Description
Test Period	How often should the test be executed.
Host	The IP address of the host for which this test is to be configured.
Port	Refers to the port at which the specified host listens to. By default, this will be NULL.
SNMPPort	The port at which the monitored target exposes its SNMP MIB; The default value is 161.
SNMPVersion	By default, the eG agent supports SNMP version 1. Accordingly, the default selection in the SNMPversion list is v1. However, if a different SNMP framework is in use in your environment, say SNMP v2 or v3, then select the corresponding option from this list.
SNMPCommunity	The SNMP community name that the test uses to communicate with the firewall. This parameter is specific to SNMP v1 and v2 only. Therefore, if the SNMPVersion chosen is v3, then this parameter will not appear.
UserName	This parameter appears only when v3 is selected as the SNMPVersion. SNMP version 3 (SNMPv3) is an extensible SNMP Framework which supplements the SNMPv2 Framework, by additionally supporting message security, access control, and remote SNMP configuration capabilities. To extract performance statistics from the MIB using the highly secure SNMP v3 protocol, the eG agent has to be configured with the required access privileges – in other words, the eG agent should connect to the MIB using the credentials of a user with access permissions to be MIB. Therefore, specify the name of such a user against this parameter.
Context	This parameter appears only when v3 is selected as the SNMPVersion. An SNMP context is a collection of management information accessible by an SNMP entity. An item of management information may exist in more than one context and an SNMP entity potentially has access to many contexts. A context is identified by the SNMPEngineID value of the entity hosting the management information (also called a contextEngineID) and a context name that identifies the specific context (also called a contextName). If the Username provided is associated with a context name, then the eG agent will be able to poll the MIB and collect metrics only if it is configured with the context name as well. In such cases therefore, specify the context name of the Username in the Context text box. By default, this parameter is set to none.
AuthPass	Specify the password that corresponds to the above-mentioned Username. This parameter once again appears only if the SNMPversion selected is v3.
Confirm Password	Confirm the AuthPass by retyping it here.
AuthType	This parameter too appears only if v3 is selected as the SNMPversion. From the AuthType list box, choose the authentication algorithm using which SNMP v3 converts the specified username and password into a 32-bit format to ensure security of SNMP transactions. You can choose between the following options: MD5 - Message Digest Algorithm SHA - Secure Hash Algorithm SHA224 - Secure Hash Algorithm 224 bit SHA256 - Secure Hash Algorithm 256 bit SHA384 - Secure Hash Algorithm 384 bit SHA512 - Secure Hash Algorithm 512 bit
EncryptFlag	This flag appears only when v3 is selected as the SNMPversion. By default, the eG agent does not encrypt SNMP requests. Accordingly, the this flag is set to No by default. To ensure that SNMP requests sent by the eG agent are encrypted, select the Yes option.
EncryptType	If the EncryptFlag is set to Yes, then you will have to mention the encryption type by selecting an option from the EncryptType list. SNMP v3 supports the following encryption types: DES - Data Encryption Standard 3DES - Triple Data Encryption Standard AES - Advanced Encryption Standard AES128 - Advanced Encryption Standard 128 bit AES192 - Advanced Encryption Standard 192 bit AES256 - Advanced Encryption Standard 256 bit
EncryptPassword	Specify the encryption password here.
Confirm Password	Confirm the encryption password by retyping it here.
Timeout	Specify the duration (in seconds) within which the SNMP query executed by this test should time out in this text box. The default is 10 seconds.
Data Over TCP	By default, in an IT environment, all data transmission occurs over UDP. Some environments however, may be specifically configured to offload a fraction of the data traffic – for instance, certain types of data traffic or traffic pertaining to specific components – to other protocols like TCP, so as to prevent UDP overloads. In such environments, you can instruct the eG agent to conduct the SNMP data traffic related to the monitored target over TCP (and not UDP). For this, set this flag to Yes. By default, this flag is set to No.
EngineID	This parameter appears only when v3 is selected as the SNMPVersion. Sometimes, the test may not report metrics when AES192 or AES256 is chosen as the Encryption type. To ensure that the test report metrics consistently, administrators need to set this flag to Yes. By default, this parameter is set to No.

Measurements made by the test
Measurement	Description	Measurement Unit	Interpretation
Data transmitted	Indicates the rate at which data was sent by this service class.	KB/Sec	WAN links have low bandwidth when compared to LAN links. Moreover, any attempt made to send or receive traffic faster than the link throughput can result in congestion. Therefore, the branch repeater should make sure that just about enough data is sent and received by the IP addresses and ports grouped under a service class to prevent congestion and optimize throughput. If the values of these measures exceed or are dangerously close to the bandwidth limit of the WAN links used by a service class, it signals a potential congestion or slowdown of traffic over one/more of those WAN links. It also indicates that you may have to reconfigure the branch repeater with more robust traffic shaping policies to prevent such unpleasant eventualities.
Data received	Indicates the rate at which data was received by this service class.	KB/Sec
Packets transmitted	Indicates the number of packets transmitted by this service class.	Number	WAN links have low bandwidth when compared to LAN links. Moreover, any attempt made to send or receive traffic faster than the link throughput can result in congestion. Therefore, the branch repeater should make sure that just about enough data packets are sent and received by the IP addresses and ports grouped under a service class to prevent congestion and optimize throughput. If the values of these measures exceed or are dangerously close to the bandwidth limit of the WAN links used by a service class, it signals a potential congestion or slowdown of traffic over one/more of those WAN links. It also indicates that you may have to reconfigure the branch repeater with more robust traffic shaping policies, acceleration rules, and compression algorithms to prevent such unpleasant eventualities.
Packets received	Indicates the number of packets received by this service class.	Number
Data dropped during transmission	Indicates the rate of traffic not sent by this service class over all its WAN links due to QoS threshold settings.	KB/Sec	QoS (quality-of-service) is a set of policies and priorities assigned to the application traffic prioritized under traffic shaping policies in BR devices. A QoS threshold allows a sender to deliver only as much data as the branch repeater allows it to send, and this data is placed on the link at exactly the right rate to keep the link full but not overflowing. By eliminating excess data, the branch repeater is not forced to discard it. Without the branch repeater, the dropped data would have to be sent again, causing delay. You can compare the value of these measures across service classes to identify that service class, the WAN links of which have dropped the maximum data. This could be owing to any of the following reasons: The bandwidth of the WAN links used by the service class is low. Hence, very rightly, a high QoS threshold has been set that allows only limited data to be sent/received over those WAN links; as a result, a large amount of data gets automatically excluded from transmissions/receptions over those WAN links, thus maximizing the speed of the links; The branch repeater has been misconfigured with a high QoS threshold that forces the WAN links used by this service class to send/receive much less data than what it can handle; this causes a lot of data to be unnecessarily dropped from transmissions/receptions, affecting the quality-of-experience in the process. In this case, you may have to fine-tune the QoS policy.
Data dropped during reception	Indicates the rate of traffic not received by this service class due to QoS threshold settings.	KB/Sec
Packets dropped during transmission	Indicates the number of packets not sent over all the WAN links used by this service class due to QoS threshold settings.	Number	QoS (quality-of-service) is a set of policies and priorities assigned to the application traffic prioritized under traffic shaping policies in BR devices. A QoS threshold allows a sender to deliver only as much data as the branch repeater allows it to send, and this data is placed on the link at exactly the right rate to keep the link full but not overflowing. By eliminating excess data, the branch repeater is not forced to discard it. Without the branch repeater, the dropped data would have to be sent again, causing delay. You can compare the value of these measures across service classes to identify that service class, the WAN links of which have dropped the maximum packets. This could be owing to any of the following reasons: The bandwidth of the WAN links used by the service class is low. Hence, very rightly, a high QoS threshold has been set that allows only limited number of packets to be sent/received over those WAN links; as a result, many data packets gets automatically excluded from transmissions/receptions over those WAN links, thus maximizing the speed of the links; The branch repeater has been misconfigured with a high QoS threshold that forces the WAN links used by this service class to send/receive fewer data packets than what it can handle; this causes a many data packets to be unnecessarily dropped from transmissions/receptions, affecting the quality-of-experience in the process. In this case, you may have to fine-tune the QoS policy.
Packets dropped during reception:	Indicates the number of packets not received by this service class due to QoS threshold settings.	Number