In this context, universal short message services are network-based sms services implemented in the operator network to serve local subscribers. The practice abstract the low level details of the protocols used to exchange short messages in the network by using a single and simple API to post messages to subscribers without caring if they are registered as 3G or 4G subscribers.

This model can be extended t by using SMPP if we want to extend delivery to foreign networks as well.

Programmable SMS is popular in the CPaaS market, it allows 3rd parties to use the short messages API for external web sites or mobile applications.

In this configuration the SMS AEF publish its APIs to the CAPIF-CF and the CAPIF-CF is responsible to authenticate 3rd party users and grant them access to authorized APIs. The CAPIF-CF can also be provisioned with rate control policies to limit each user on API calls. The CAPIF-CF can be configured with an online or offline interface to a charging function to gain the ability to charge 3rd party users.

It is possible to share the SMS-AEF stack for use with internal services and 3rd party services if required.