Diameter is a replacement of SS7, we all know. But why can’t we use SS7 in an LTE network? SS7 allows operators to set up calls, track users as they roam and deliver messages. Diameter delivers these functionalities AND it is an IP based protocol that can deliver more than SS7. Diameter is used to exchange policies, e.g. bandwidth allocation, QOS information about a roaming subscriber. It is used to handle subscriber related data between the MME and HSS. Diameter is also used to handle real-time charging. Moreover, protocol extensions of Diameter allow the flexibility to add even more functionality to it.
Ashruti Singh Senior Product Marketing Manager- SAP Mobile Services