This object is used to specify the type of test to run for the ISDN-PRI B channel. There are no results stored locally for a loopback test. Loopback of the individual B channels is supported. AAL2 Loopback is also supported on the D channel. In order to run these tests, the CO-IWF must first set the value of this object appropriate to the test that needs to be run. The CO-IWF should then set the value of isdnPriBChannelAdminStatus to 'testing'. The CO-IWF should verify that the test is in progress by checking that the value of isdnPriBChannelOperStatus is equal to 'testing'. Once testing is complete the CO-IWF must set the isdnPriBChannelAdminStatus to a value other than 'testing'.