Operator

A mobile operator in North America with 127 million subscribers.

Campaign Scope

60 tariff plans monitored during one quarter

Case Description:

Issue arose after VoLTE roaming was implemented with multiple partners. Affected call types: local, home, and international. Operator's monitoring systems failed to detect the discrepancy.

Root cause: 

• Limited testing was carried out.
• Testing focused on VoLTE scenarios.
• No testing was carried out on legacy services.
• Changes implemented to bill VoLTE impacted billing of legacy services.