STE (Service Technology Enabler) is aimed to provide simple interface to external applications require VAS services given by underlying VAS or network nodes. The interface shall be based on HTTP Representational State Tranfer (REST) or SOAP. The REST is more prefereable because its simplicity, as natural as HTTP request via web browser. It is also known as light weight web service compared to SOAP based. The Therefore, VASGW acts as web service provider to application layers.

STE requires 4 interfaces to exchange data between applications and VAS or network nodes.
  1. Application Interface (IA)
    This interfaces the external application (i.e. STE users) and underlying VAS nodes providing requested services.
  2. Signaling Interface (IS)
    Signaling interface connecting STE with signalling nodes over STP.
  3. VAS Interface (IV)
    - Support SMPP 3.4 interface to connect to XL SMSC
    Support customized TLV optional parameters without additional cost
  4. Billing Interface (IB)
    - Support Diameter base protocol (RFC 3588) as based for Diameter Credit Control Application (DCCA)
    - Support Diameter Credit-Control Application (RFC 4006) as interface to Billing System
    Extensible command code and/or new AVP without additional cost
    - Support SOAP/XML to interface with external application with HTTP 1.1 as transport protocol

STE shall implement VAS application servers that complied with JSR-240 JAIN SLEE standards. Standardization on application is required for the sake of publicity and openess thus removing dependency to any proprietary product.

Telco application is moving to software components based architecture to increase its efficieny, smaller 
footprint while stringent telco application grade of service is maintained that is service with low latency and high availability. 

JSR-240 is currently the only open standard for such telco application server .