CBR Service Classes 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.

After service class configuration, administrators may want to check how well the branch repeater accelerates the traffic to and from each service class, how effective the compression algorithm mapped to each service class is, and whether any data or connection is left unaccelerated. This analysis will enable administrators to identify those service classes for which many connections are still unaccelerated and those that use poor compression algorithms. To perform this analysis periodically, the CBR Service Classes test can be used. For each service class configured in the branch repeater, this test monitors the accelerated traffic on the service class and reports the following:

  • For which service class has the branch repeater not accelerated the maximum data and connections?
  • For which service class has the branch repeater being unable to compress data traffic significantly?

Such service classes are candidates for configuration tuning.

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

Current accelerated connection

Indicates the current number of accelerated connections for this service class.

Number

 

Total accelerated connection

Indicates the total number of accelerated connections for this service class since system startup.

Number

A high value is desired for this measure.

Total accelerated data

Indicates the total amount of data that was accelerated for this service class during the last measurement period.

KB

A high value is desired for this measure.

Total non-accelerated connections

Indicates the total number of non-accelerated connections for this service class since system startup.

Number

A low value is desired for this measure.

Compare the value of this measure across service classes to know for which service class the maximum number of connections has not been accelerated. The reasons for this will have to be investigated. If ineffective traffic shaping policies or compression rules are responsible for the gradual deterioration in the acceleration rate of the service class, then such policies will have to be revamped to improve performance.

Total non-accelerated data

Indicates the total amount of data that was not accelerated for this service class during the last measurement period.

KB

Compare the value of this measure across service classes to know for which service class the maximum amount of data has not been accelerated. The reasons for this will have to be investigated. If ineffective traffic shaping policies or compression rules are responsible for the gradual deterioration in the acceleration rate of the service class, then such policies will have to be revamped to improve performance.

Accelerated data before compression

Indicates the amount of data that was accelerated for this service class before compression during the last measurement period.

KB

 

Data transmitted after compression

Indicates the amount of data that was transmitted for this service class after compression, during the last measurement period.

KB

Compare the value of the Data transmitted after compression and the Data transmitted before compression measures for a service class to figure out how effective compression was. If compression did not reduce the data transmitted for any service class, it is an indication that a poor compression algorithm has been employed by that service class. You will then have to reconfigure the compression ratio that applies to that service class.

Data transmitted before compression

Indicates the amount of data that was transmitted for this service class before compression, during the last measurement period.

KB

Data received after compression

Indicates the amount of data that was received for this service class after compression, during the last measurement period.

KB

Compare the value of the Data received after compression and the Data received before compression measures for a service class to figure out how effective compression was. If compression only mildly reduced the data received for any service class, it is an indication that a poor compression algorithm has been employed by that service class. You will then have to reconfigure the compression ratio that applies to that service class.

Data received before compression

Indicates the amount of data that was received for this service class before compression, during the last measurement period.

KB