Method and system for determining a mobile network operator identifier

A non-transitory computer-readable medium with a computer program comprising software instructions which, when implemented by a programmable device, implement steps for determining a mobile network operator identifier, the steps including:

• retrieving a response previously stored in a Call Detail Record (CDR) collected passively during call set-up in a telecommunications network where the call-set up is initiated by a first mobile device having an associated first mobile device subscriber number to connect to a second mobile device having a second mobile device subscriber number, the call set-up comprising sending a request to a portability server, the portability server sending a response formatted according to a predetermined format depending on a type of cellular technology;
• analyzing said stored response without performing an active query to a number portability database or any other external system during the analyzing step and extracting an identifier of the mobile network operator associated the second mobile device subscriber number, and
• storing, in a dedicated storing structure, an association between the mobile network operator identifier and the second mobile device subscriber number of the second mobile device.

A system for determining a mobile network operator identifier in relation to a mobile device subscriber number, and to a telecommunications network event, the telecommunications network event comprising a call set-up initiated by a first mobile device having an associated first mobile device subscriber number to connect to a second mobile device having a second mobile device subscriber number, the call set-up comprising sending a request to a portability server, the portability server sending a response formatted according to a predetermined format depending on a type of cellular technology, the system comprising at least one processor configured to implement:

• a retrieval module configured to retrieve said previously stored in a Call Detail Record (CDR) collected passively during said call set-up;
• an analyzing module configured to analyze said stored response without performing an active query to a number portability database or any other external system during the analyzing step and to extract an identifier of the mobile network operator associated the second mobile device subscriber number, and
• a storing module, configured to store, in a dedicated storing structure, an association between the mobile network operator identifier and the second mobile device subscriber number of the second mobile device.