NG-c (The control-plane part of NG)

Last updated on May 16, 2023

Introduction

NG-c (Next Generation Control-plane) is the control-plane part of the Next Generation Network (NGN), which is a packet-based network that is designed to offer high-quality services such as voice, video, and data to users. The control-plane part of NGN is responsible for managing the network, including routing, signaling, and traffic management. In this article, we will explain in 2000 words the NG-c architecture and its components.

NG-c Architecture

The NG-c architecture comprises various components, including the Operations Support System (OSS), the Resource and Admission Control Function (RACF), the Gateway Control Function (GCF), the Policy Decision Function (PDF), the Charging and Billing Function (CBF), and the Home Subscriber Server (HSS). We will discuss each of these components in detail.

Operations Support System (OSS)

The OSS is responsible for managing and controlling the NGN. It provides the network operators with tools to monitor, configure, and control the network. The OSS comprises various functions, including the Fault Management Function (FMF), Configuration Management Function (CMF), Performance Management Function (PMF), and Security Management Function (SMF).

The FMF is responsible for detecting and reporting faults in the network. It alerts the network operators and suggests corrective actions to resolve the faults. The CMF is responsible for managing the configuration of the network elements. It ensures that the network elements are correctly configured and that the configuration changes are implemented correctly. The PMF is responsible for monitoring the performance of the network. It collects performance data and generates reports to help the network operators optimize the network's performance. Finally, the SMF is responsible for managing the network's security. It identifies security threats and takes appropriate measures to protect the network from attacks.

Resource and Admission Control Function (RACF)

The RACF is responsible for managing network resources such as bandwidth, CPU cycles, memory, and storage. It ensures that the network resources are optimally utilized and that the network does not become congested. The RACF comprises various functions, including the Admission Control Function (ACF), the Resource Management Function (RMF), and the QoS Management Function (QMF).

The ACF is responsible for admitting or rejecting new sessions based on the network's available resources. It ensures that the network resources are not overloaded and that the network's quality of service (QoS) is maintained. The RMF is responsible for managing the network resources dynamically. It allocates and releases resources based on the network's demand. The QMF is responsible for managing the QoS of the network. It ensures that the network's QoS is maintained by prioritizing traffic based on its importance.

Gateway Control Function (GCF)

The GCF is responsible for managing the gateway functions of the NGN. It ensures that the gateways are correctly configured and that the traffic is correctly routed through the gateways. The GCF comprises various functions, including the Interworking Function (IWF), the Media Gateway Control Function (MGCF), and the Signaling Gateway Control Function (SGCF).

The IWF is responsible for converting the traffic between different networks, such as from PSTN to IP and from IP to PSTN. The MGCF is responsible for controlling the media gateway, which is used to convert the traffic between different media types, such as voice, video, and data. The SGCF is responsible for controlling the signaling gateway, which is used to convert the signaling messages between different protocols, such as from SIP to ISUP.

Policy Decision Function (PDF)

The PDF is responsible for managing the policies of the NGN. It ensures that the network policies are correctly configured and that the traffic is correctly routed according to the policies. The PDF

comprises various functions, including the Policy Enforcement Function (PEF) and the Policy Information Function (PIF).

The PEF is responsible for enforcing the network policies. It monitors the traffic and applies the policies to control the traffic flow. The PIF is responsible for storing and retrieving the policy information. It provides the policy information to the PEF and other network functions that require it.

Charging and Billing Function (CBF)

The CBF is responsible for managing the charging and billing of the NGN. It ensures that the users are correctly charged for the services they use and that the billing information is accurately recorded. The CBF comprises various functions, including the Charging Function (CHF) and the Billing Function (BLF).

The CHF is responsible for collecting the charging information from the network elements. It measures the usage of network resources by the users and calculates the charges based on predefined charging rules. The BLF is responsible for generating the bills for the users. It collects the charging information from the CHF and creates the bills according to the billing rules.

Home Subscriber Server (HSS)

The HSS is responsible for storing and managing the subscriber information of the NGN. It ensures that the subscriber information is correctly stored and that the authentication and authorization of the subscribers are correctly performed. The HSS comprises various functions, including the Authentication Function (AF), the Authorization Function (ZF), and the Subscription Data Function (SDF).

The AF is responsible for authenticating the subscribers when they access the network. It verifies the identity of the subscribers and ensures that they have the necessary permissions to access the network. The ZF is responsible for authorizing the subscribers' access to the network resources. It checks the subscribers' permissions and grants access to the authorized resources. The SDF is responsible for storing the subscribers' information, such as their profiles and service subscriptions. It provides the subscriber information to other network functions that require it.

Conclusion

NG-c, the control-plane part of NGN, plays a crucial role in managing and controlling the network. It comprises various components, including the OSS, RACF, GCF, PDF, CBF, and HSS, which work together to ensure the smooth operation of the NGN. The OSS provides tools for network management, while the RACF manages network resources and admission control. The GCF handles gateway functions, the PDF manages network policies, the CBF handles charging and billing, and the HSS stores and manages subscriber information. Together, these components form a robust control-plane architecture that enables the NGN to deliver high-quality services to users.