The implementation of pure MLP which is used in Location Based Platforms (LCS client) is rare, the LCS Client could communicate with the GMLC through the OSA/Parlay. It is already showed on figure 2.1.
OSA/Parlay[4] is an open application programming interface (API) for application access to telecom network resources. OSA/Parlay technology integrates telecom network capabilities with IT applications via a secure, measured, and billable interface. OSA/Parlay APIs are network independent, and applications can be hosted within the telecom network operator's own environment, or by external third party service providers. API is developed by The Parlay group which is a consortium of vendors, service providers and operators. 3GPP has adopted API specifications as Open Service Access (OSA).
Parlay X is a web-services API. It is standardized jointly by ETSI, Parlay and 3GPP. Parlay X is a simplified web service interface to telecom network functionality. It may be used in conjunction with the base OSA/Parlay APIs, or on its own.
The basic architecture of Parlay/OSA and Parlay X is showed on the following figure.
(souce: ETSI ES 202 504-16 v1.1.1 page 8)
Figure 6 shows that OMA/MLP is used between the Parlay X Gateway and GMLC. It is also used between the Parlay Gateway and GMLC/MPC.