1. FlexE - Channel Control Work in the IETF
Loa Andersson
Mach Chen
Jie Dong
Zongpeng Du

2. Multi-hop Flex Ethernet Channel
The definition of the MAC layer and PHY layer for FlexE has been defined by OIF in the FlexE 1.0.
The main features are:
multiple PHYs bonding, forming a virtual link with large bandwidth, and chopped into slots
Slot-based encoding on the PHYs, each MAC client has its particular slots (5Gbits/s per slot)
The most straightforward scenarios are:
Directly connected FlexE routers
Flexe routers connected over an OTN network
Another scenario is multi-hop FlexE channel, which will be the main topic of this slide; it means that FlexE can also be used in a pure Router network
In draft-izh-ccamp-flexe-fwk-00, this scenario is called “the back-to-back FlexE use case”
Interfaces are FlexE based
A FlexE client have specific slots on the interface, i.e., ensured bandwidth on the interface
Forwarding in the Routers can be Ethernet/MPLS/IP based
draft-izh-ccamp-flexe-fwk-00

3. Benefits of Multi-hop FlexE Channel
“Hard pipes” – paths with bandwidth the can not be infringed upon nor exceeded.
MPLS hard pipes were specified in RFC 7625 “Architecture of an IP/MPLS Network with Hardened Pipes”
“IP Hard pipes” is now under study – draft will be posted after the cut-off is lifted
In IP Networks we sometimes need to provide bandwidth guaranteed service
For (G)MPLS networks this is done by the use of MPLS-TE
FlexE is a potential solution for part of the IP “hard pipe” technology
FlexE provides guaranteed bandwidth, which is beneficial for latency of the service.
FlexE can be used to establish a multi-hop FlexE Channel, and to ensure the QoS E2E
FlexE offers a very stable hardware guarantee to the QoS
For some set of services FlexE can be used to improve QoS in IP networks

4. Potential impact from FlexE in work in IETF
The work will start in CCAMP (draft-izh-ccamp-flexe-fwk)
This draft is a convergence of ideas from several other individual draft
It gives a high level description of what FlexE is
The draft outlines
Use cases, e.g. ways to inter-connect FlexE capable equipment
Requirements, e.g.
FlexE signaling Architecture and Framework,
Solutions, extensions to IETF protocols
Applicability
The draft also introduces FlexE specific terminology

5. Potential impact from FlexE on work in IETF
CCAMP
Use Cases, Requirements, Framework, Architecture, extensions to RSVP-TE to establish signaled FlexE channels
MPLS
Coordination with CCAMP when the MPLS data plane is used
RTGWG
Potentially work on IP (unicast and multicast) Hard Pipes
PCE
Work in coordination with CCAMP on FlexE path computation
DETNET
FlexE impact on deterministic networking
OSPF and ISIS
Solutions for FlexE Traffic Engineering and capability announcements
TEAS
Coordination with CCAMP/MPLS on traffic engineering architecture and solutions

6. Thanks

7. Appendix: Flex-Ethernet Overview
An example to introduce FlexE concept:
The FlexE interface between Node 1 and Node 2 includes 4 physical links (4*100G), called FlexE Group. They are bonded together to form a virtual link with large bandwidth to serve FlexE Clients
In the Figure, there are two FlexE Clients. Their MAC frames are 64B/66B encoded, and the 64B/66B bitstream will be scheduled by the FlexE shim, and distributed sequentially into the calendar and sub-calendar. For a FlexE group composed of 4 bonded 100G PHYs, logically, the calendar contains 80 slots (5Gbits/s per slot)
Node1 and Node2 share the same calendar, which contains the information about which FlexE client a slot belongs to. The calendar is negotiated or configured before the data transferring, and is used for mapping the FlexE clients into the FlexE group and demapping the FlexE clients from the FlexE group
MAC
FlexE Shim
PHY
Node 1
Node 2
FlexE Group:
Bonded Ethernet PHYs
Forming a virtual link
FlexE Clients：
Virtual MAC interface, whose rate is not limited to the existing Ethernet PHY rates defined in IEEE
Illustration of FlexE Calendar Distribution
Illustration of Data Flow for FlexE Mux
Cited from OIF-FLEXE-01.0
Cited from OIF-FLEXE-01.0