Number Lookup, also known as HLR (Home Location Register) lookup, is a telecommunications service that dynamically contacts a central database (on the mobile operator’s side) that contains details of each mobile phone subscriber authorised to use the core network. A lookup or number "dip" can be used to determine the validity of the number (MSISDN), the state of the number and information to aid with routing SMS and calls. See the Mobile Number Lookup service of the Location API available in Melrose Labs Identity and Location.
Melrose Labs Identity and Location
Melrose Labs: We deliver innovative services in cloud communications across mobile, fixed-line, satellite and internet. Our services increase the success of businesses and other organisations through better communication with their staff and customers.