So in reality this sentence:
When a call is made to the ported telephone number, the initiating service provider switch launches a query to its LNP call routing database to determine whether the telephone number has been ported.
When a call is made to the ported telephone number, the initiating service provider switch launches a query to an LNP call routing database to determine whether the telephone number has been ported.
The reason I say that is depending upon the decisions made by the "initiating service provider" they may or may not have their own LNP database. In the case of small (underfunded) service providers - most VoIP providers - they likely do not. Instead they choose to use the LNP Database Query Service of one or more larger providers. In this case they simply pay fractions of a penny for each query, or have some other business relationship in place.
In my case I researched this process roughly a year ago because callers to my ported number were randomly receiving a recording that the "Mobile number they were trying to reach had traveled beyond the service range" or some such thing. The ported number was never a mobile number, not originally or after the port.
Turns out the company that received my ported number was using the LNP database of the original provider. In addition there was evidently some LCR (Least Cost Routing) magic that added more confusion (namely the mobile number thing). This led me to believe that the original was always involved in the process of the call with the simple purpose of obtaining an LRN. In fact this is not always true but apparently is fairly common.