User Story
The customer has developed its own mobile application, that is available for end-users. The customer wants to provide an additional service for his clients: to check the quality of the sound during calls via this mobile application.

This will become an additional flexible tool for end-users, that will assure the sound quality check. Moreover it will help the administrator to check and troubleshoot possible issues with the sound quality.

The user will use iLBC codec for calls, so it's needed to record the call and play the record in iLBC codec.

Use Cases

Use case #1: Checking sound quality via IVR

Roles: End-user, IVR.

Preconditions:

• There is a Call Recording node instance present in a system configuration.
• There is ABC customer is the system. It has 111222333 account under it. The end-user has a mobile app installed on his phone and 111222333 account is registered in the app.
• 123456789 number is set up in the system for 'Sound quality check' service. It is configured that the speech for sound quality check will be recorded for 10 seconds (this option can be changed).
• The period of keeping records of such test quality calls is set up as 1 month (this option can be changed).

Scenario:

• The user wants to check the sound quality using the mobile application. So the user dials 123456789 number from his 111222333 account.

• The user hears the prompt 'Hi. You called sound quality verification service. Please say something after the tone.'
• The user speaks for 10 seconds. His message is being recorded.
• Another tone is played. After this the user hears the recorded speech, so the user can check the quality of the sound.
• The user hears the prompt 'This is the end of the recorded message. Good bye.'
• The record is saved in the system for 1 month.
• After 1 month the record is automatically deleted from the system.

Use case #2: Troubleshooting with the help of the record of the sound quality check (good quality)

Roles: End-user, IVR, Administrator.

Preconditions:

• There is a Call Recording node instance present in a system configuration.
• There is ABC customer is the system. It has 111222333 account under it. The end-user has a mobile app installed on his phone and 111222333 account is registered in the app.
• 123456789 number is set up in the system for 'Sound quality check' service. It is configured that the speech for sound quality check will be recorded for 10 seconds (this option can be changed).
• The period of keeping records of such test quality calls is set up as 1 month (this option can be changed).

Scenario:

• On April, 1 the user calls administrator and asks to give back money, that he spent for the call, as the quality of the sound was bad.

• The administrator asks whether the user has checked the sound quality.
• The user has not checked the sound quality, so the administrator asks him to do so.
• The user checks the sound quality by dialing 123456789 number from his 111222333 account.
• The user hears the welcome prompt. The user speaks for 10 seconds. His message is being recorded.
• After this the user hears the recorded speech. The record is saved in the system for 1 month.
• The administrator checks the record of sound quality check for 111222333 account, that was made on April, 1.
• The administrator listens to the record. He hears that the quality of the sound was good.
• The administrator informs the user that sound quality check record proves the quality is good, and there is no reason for chargeback.

Use case #3: Troubleshooting with the help of the record of the sound quality check (bad quality)

Roles: End-user, IVR, Administrator.

Preconditions:

• There is a Call Recording node instance present in a system configuration.
• There is ABC customer is the system. It has 111222333 account under it. The end-user has a mobile app installed on his phone and 111222333 account is registered in the app.
• 123456789 number is set up in the system for 'Sound quality check' service. It is configured that the speech for sound quality check will be recorded for 10 seconds (this option can be changed).
• The period of keeping records of such test quality calls is set up as 1 month (this option can be changed).

Scenario:

• On April, 5 the user calls administrator and informs that the quality of the sound is bad. The user informs that on April, 3 he did sound quality check and the quality was bad too.

• The administrator checks the record of sound quality check for 111222333 account, that was made on April, 3.
• The administrator listens to the record. He hears that the quality of the sound was indeed bad.
• The administrator informs the user that they will analyze the reasons of such a poor quality.
• The administrator investigates the sound issues on their side.

Other requirements / constraints

The requested feature is an analogue of Skype Echo/Sound Test Service. This service will prompt the user to record a message, and then play it back for him – so the user will know right away if the sound is working.

The user will use iLBC codec for calls so such calls should be properly recorded and avaialble for re-playing. That doesn't enforce format of  internal storage but just add expclicit requirement on supported codec set.