Liaison statement
The Disaggregated Architecture of BNG in BBF TR-384

Dear colleagues,

We would like to inform IETF that BBF has approved a new technical report
TR-384, titled “Cloud Central Office Reference Architectural Framework”, which
provides a common cloud platform reference architecture for restructuring the
Central Office. Operators will have the opportunity to run a single network
with all varieties of access technologies, and flexibly deploy innovative
services with shortened time-to-market.

TR-384 shows a way of disaggregating the traditional Broadband Network Gateway
(BNG), i.e. the IP service edge of a fixed network, into various network
functions and separates service control plane and user plane. Further, the BNG
service control plane and its user plane can be separately deployed, with the
service control plane centralized and virtualized providing significant
benefits such as centralized session management, flexible address allocation,
high scalability for subscriber management capacity, and cost-efficient
redundancy, etc., while the user plane distributed and localized. The User
Plane Management module in the BNG service control plane centrally manages the
distributed BNG user plane as well as the setup, deletion, and maintenance of
interfaces between the BNG control plane and the user plane. The details
regarding the interfaces need to be further investigated.

Currently in IETF, the standards work on the interfaces of the disaggregated
BNG has started. For example, the draft “Information model of control plane and
user plane separation BNG”:
https://datatracker.ietf.org/doc/draft-cuspdt-rtgwg-cu-separation-infor-model/.

In addition, the draft “Requirements for the protocol of the control plane and
user planes separation BNG”:
https://datatracker.ietf.org/doc/draft-cuspdt-rtgwg-cusp-requirements/

We look forward to continued IETF progress on the drafts for interfaces of the
disaggregated BNG which will give operators a complete view of the BNG
disaggregation. It also can provide a standardized way to manage multiple
vendors in the BNG access devices and improve the cooperation and
interconnection of different vendors’ devices. Therefore, the standards works
are very important to the BNG disaggregation’s deployment and development.

Please find the link to BBF TR-384 “Cloud Central Office Reference
Architectural Framework”
https://www.broadband-forum.org/technical/download/TR-384.pdf

Sincerely,

Michael Fargano,
Broadband Forum Technical Committee Chair