4. Differences between solutions

For the convergence between IP and PSTN (telephone) networks to be successful, the solution for end-to-end QoS requires that an agreement be established between service providers to determine IP performance parameters and QoS objectives, enabling the deployment of mechanisms that support these objectives and signaling protocols.

NGN and IMS (IP Multimedia Subsystem) describe functions on its control plane in network architecture, and can be classified as either service control or network control [10] .

The service control function is based on SIP, and all standards groups support it, but there are also other service control protocols (SS7 for telephony). The network control function includes resource and admission control, service decision rules (policy),...