Complex sentence: This should be contrasted with stimulus protocol such as MiNET which carry only event data and are not aware of system state and so were commonly used in traditional telephony architectures that relied on centralized call control.
Split into simpler sentences: This should be contrasted with stimulus protocol such as MiNET which carry only event data and are not aware of system state. As a result, stimulus protocols were commonly used in traditional telephony architectures that relied on centralized call control.