BNG CUPS model

May 5, 2023
BNG CUPS model
Control and User Plane Separation (CUPS) is a technology that separates control and user planes in communication networks. This means that network management and data transfer occur on different physical and logical elements, which increases the flexibility and scalability of the network.

The Stingray SG concept supports the trend of the transition from the classic BNG device to the disaggregated BNG (DBNG) concept through the UP and CP separation. Let’s consider its benefits in more detail.


Multi-Service BNG

In the classic implementation of network infrastructure, a broadband service gateway is a multiservice device (Multi-Service BNG) that manages authorization, subscriber access to the Internet, authentication, bandwidth allocation, IP address allocation and accounting. With the development of Internet capabilities, the requirements are getting higher: adequate processing of the increasing volume of traffic is also necessary, taking into account the future growth of the Internet provider, and support for VoIP, IPTV, OTT, streaming video, gaming, and others.


If the control and user-level functions are on the same device, this is inefficient for both levels.

For user experience, speed is important, and for control – the number of connected devices and integration interfaces. Because of this, it is necessary to determine in advance the necessary resources for MS-BNG, which can be used efficiently. This limits scaling and increases development costs.

Disaggregated BNG (DBNG)

To distribute the load and normalize the usage of the BNG device, the concept of disaggregated BNG (DBNG) has appeared. It involves the separation of control and user plane (CUPS) levels so that the architecture meets the increased number of subscribers and bandwidth requirements. CUPS also simplifies operation by supporting a single management interface on the CP to manage all UP.

Separating UP and CP allows to change the approach to network expansion.

Typically, the control level and the user level have different performance and scaling requirements: for the user level, the bandwidth for each user is important, and for the control level, the number of connected devices and integration interface requirements. In the case of MS-BNG, to process a large amount of traffic, it is necessary to make special hardware platforms that have a certain lifetime and limited development potential. Separation of control from traffic allows to allocate the necessary resources for maximum scaling and development of functionality.


CUPS in VAS Experts products

The VAS Experts traffic monitoring and analysis system uses the fastDPI process in the User Plane role to perform the following tasks:

  • Traffic Management
  • Collection of statistics on subscriber traffic
  • Applying QoS Policies
  • Routing and Forwarding – BGP, OSFP
  • Lawful Interception – Traffic mirroring
  • Local management

In the Control Plane role, a fastPCRF process is used to perform the following tasks:

  • Session Management of IPoE, PPPoE subscriber authentication
  • AAA client – subscriber authorization, and authentication
  • Accounting – subscriber traffic accounting
  • Assigning and managing IP addresses – assigning IP addresses / prefixes via DHCPv4, DHCPv6
  • WLAN-GW Access – Controller for access point management

We considered the main scenarios of BRAS components interaction from VAS Experts in the article about BRAS state diagram.

We use cookies to optimize site functionality and give you the best possible experience. To learn more about the cookies we use, please visit our Cookies Policy. By clicking ‘Okay’, you agree to our use of cookies. Learn more.