Broadband Network Gateway: A new access portal for the web
Capacity takes a look at the Broadband Network Gateway and its role in ISP network models.
What is the Broadband Network Gateway?
The Broadband Network Gateway (BNG) allows subscribers to connect to a broadband network through an access portal. It creates and manages subscriber sessions, aggregating traffic from various subscriber sessions from an access network, and routing it to the network of the Internet Service Provider (ISP) or Network Service Provider (NSP).
The BNG is typically deployed by the service provider and it is present at the first point of aggregation in the network. Cisco’s first aggregation point, for example, is its ASR 9000 series router, which is configured to act as the BNG. Because subscribers connect directly to this router, the BNG is able to manage subscriber access and other security functions.
The BNG therefore not only acts as a router, but is also said to effectively communicate with the authentication, authorisation and accounting (AAA) server and consequently perform session management and billing functions. Furthermore, the service provider is able to provide more customised broadband packages for its subscribers as the BNG identifies the different needs of each customer.
What is the BNG's role in ISP network models?
The BNG is essentially designed to deliver information from the subscriber to the ISP, but the manner in which this occurs is dependent on the model of the network. For the NSP model, the ISP (or retailer) provides the subscriber with direct broadband connectivity. The BNG acts as the router and it connects the core network via uplinks.
For an Access Network Provider model the process differs. In this instance, a network carrier (or the wholesaler) will own the network infrastructure and provide the broadband connection to the subscriber. However, because the wholesaler will not own the broadband network itself, it instead connects to one of the ISPs that does manage the broadband network. The BNG’s role is then to pass subscriber traffic on to one of several ISPs, a process which is implemented either by Layer 2 Tunnelling Protocol (L2TP) or Layer 3 VPN.
Which technology providers are already using BNG?
Ericsson introduced its BNG gateway last year on its SSR 8000 Smart Services Router, which is designed to provide service providers with the ability to offer personalised, high-quality services.
Ericsson’s BNG is said to offer a variety of interfaces and optimises advanced services for an enhanced user experience, as well as reducing the operational cost of operator’s fixed broadband IP networks.
While Ericsson’s BNG offers 100G capacity to support the increasing demand of cloud and high-definition streaming services, this March Huawei launched what it claims to be the industry’s largest capacity BNG board.
The Huawei BNG has a capacity of 240G and is designed to meet the demand from operators for larger capacity networks in order to be able to guarantee premium service transmission and improved end-user experience.
Huawei’s BNG board is said to be able to sustain a sizeable amount of point-topoint protocol over Ethernet (PPPoE) and IP over Ethernet (IPoE) subscribers, transmit multiple services at any one time as well as provide IPv4 and IPv6 dual-stack access thanks to its extensive capacity.
How will BNG develop in the coming years?
In a statement Huawei said that the BNG field has entered a 200G access board era. With the arrival of the ultra-broadband network in recent years, traffic has significantly increased, as has the demand for faster and larger bandwidth.
According to a report by solutions provider Alcatel-Lucent, the bar is being raised and a move is being made towards the removal of the boundaries and limitations of today’s broadband services and CPEs.
Customers want a richer, more personalised experience when using the internet that utilises all that it has to offer.