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Liaison statement
Converged Core and single CUPS architecture

Additional information about IETF liaison relationships is available on the IETF webpage and the Internet Architecture Board liaison webpage.
State Posted
Submitted Date 2018-10-03
From Contact Lincoln Lavoie
To Groups i2rs, RTG, rtgwg
To Contacts Susan Hares <>
Jeffrey Haas <>
Chris Bowers <>
Jeff Tantsura <>
Alvaro Retana <>
Deborah Brungard <>
Martin Vigoureux <>
Cc Deborah Brungard <>
Susan Hares <>
Routing Area Working Group Discussion List <>
David Sinicrope <>
Chris Bowers <>
Martin Vigoureux <>
Alvaro Retana <>
The IETF Chair <>
Russ White <>
Jeff Tantsura <>
Interface to the Routing System Discussion List <>
Response Contact
Purpose For information
Attachments LIAISE-225_ietf-cups_FINAL CORRECTED
Liaisons referring to this one Potential RTGWG work related to the disaggregated BNG architecture
In March 2018, BBF sent a liaison to the IETF regarding ‘The Disaggregated
Architecture of BNG in BBF TR-384’. This liaison was for information only and
by no means meant that the BBF had already selected a protocol for use.

The Wireless-Wireline Convergence (WWC) work area of the BBF has embarked on an
effort to specify 5G Fixed Mobile Convergence in collaboration with 3GPP. More
specifically, the BBF is sending to 3GPP requirements on the converged 5G core
interfaces to be addressed in the release 16 timeframe. A part of this
collaboration the BBF work is expected to result in changes to CUPS interfaces
in order to support some BNG functionality. This was not clear to us at the
time of the previous liaison. 3GPP is working on extensions to PFCP as defined
in 3GPP Release 15 (references TS23.214 and TS 29.244 from 3GPP). For
information, 3GPP is conducting a study for Release 16, where there is a
proposal to have a Service Based Interface for N4. Reference TR 23.742 from

The BBF has yet to perform a study on the feasibility of using a single
protocol to allow multi-dimension inter-operability and satisfy the
requirements of both TR-384 and our FMC work. The BBF is studying the two use
cases “BNG disaggregation” and “FMC interworking” to determine if common
requirements and therefore opportunities for engineering re-use. That key
consideration will influence how we view any solutions that independently
emerge in the industry.

We trust this information is useful and welcome further dialog with respect to
the above.