What's the difference between short messages inside and outside the network and Monternet?

For example, if you are a mobile user, then the network refers to the user network composed of all mobile users, while other users such as Unicom and Telecom are outside the network. Monternet short message service refers to consumption by sending short messages to some value-added service ports. For example, opening a QQ member with a mobile phone is Monternet SMS service.