However, if could happen that the technician that designed these configurations made a mistake, and designed a SetParameterValues to configure the same parameter twice with different values. TR-069 A.3.2.1 specifies that in this case, the CPE should not modify any of the parameters included in the SetParameterValues, instead, it should return an error. If the protocol is not correctly implemented in the CPE and the CPE does not return an error, it will be unknown which of the two different values has been applied in the CPE, since there is not a specific order established that the CPE should follow to apply changes sent in the same SetParameterValues.
The case of incorrect provisioning
For example, this router shows an error in test 5.58 from ATP-069. This test case has been designed to detect this problem. dBm069 shows that this test has failed:
When selecting this test case, the "Execution Datails” window shows that an error has been detected when the ACS sends the SetParameterValues, and also when reading the values afterwards with the GetParameterValues.
Clicking in this window on the SetParameterValues line, we can see at the "Test Log” window that a SetParameterValues has been sent trying to configure the same parameter twice with different values
The details of the SetParameterValuesResponse show that the CPE has accepted the SetParameterValues, instead of reporting an error:
The CPE should not have modified the values of any of the parameters sent in that SetParameterValues. The next GetParameterValuesResponse shows that the parameters have been modified. This is an error in the implementation of TR-069 protocol in the CPE that can cause interoperability problems.
List of consequences for user, technical staff, Service Provider