Liaison statement
LSout to IETF on the Optical Cloud Networks (OCN)

1. Overall description:

Background of ETSI ISG F5G Advanced architecture [1]

The next generation of fixed network needs support the growing number of cloud
services requiring high bandwidth and/or low latency connections. Built on
previous generations of fixed networks, the 5th generation is being defined by
ETSI Industry Specification Group (ISG) F5G to provide the evolution required
to match and further enhance fixed networking services. ETSI ISG F5G fixed
networks will play an essential role in the evolution of the “fibre to
everything” vision. Fixed networks have always offered the highest bandwidths
and availability. The development of a full fibre solution will help to support
the most demanding applications.

The F5G Advanced Architecture [1] has been specified to improve and evolve the
E2E optical fixed network architecture. The improvement and evolution include:
1) Network technologies such as Wi-Fi® 7; FTTR, 50G-PON, fgOTN, 800G OTN. 2)
Computing for enhancing networks and services. 3) Coordinated slice management.
4) Northbound interface to support Network as a Service (NaaS). 5)
Service-aware Fibre networks by the addition of Optical Cloud Network (OCN)
features including E2E service management, premium private line services, and
mission critical cloud services.

The Optical Cloud Network (OCN) Architecture [2]

ETSI GR F5G-0018 F5G Optical Cloud Networks Architecture describes the
architecture and the technical requirements of the Optical Cloud Network (OCN),
including its underlay Optical Transport Network (OTN) (new standards in OTN
including fine grain OTN (fgOTN), ETSI ISG F5G refers to this as (fg)OTN)
infrastructure and the control interfaces used to control the optical services
and connections. It also specifies the key functions of the Optical Service
Protocols (OSP) which are running on the OCN control interfaces.

The emerging trends in the F5G Advanced architecture is the support of cloud
services:

a. The majority of F5G-A services are deployed in the Cloud Data Centres,
taking full advantage of shared cloud infrastructure. In the OCN Architecture
provides the network infrastructure enabling efficient, guaranteed, reliable
cloud service networking. b. The F5G Advanced network requirements of these
cloud services cover a wide range of network characteristic including
supporting the highest quality service experience.

In general, network access to cloud services can be categorized into the
following: • Optical Access network for both residential and SME broadband
users. • Access networks for large enterprises need a variety of bandwidths.
OTN has been enhanced with a wider bandwidth range for these applications. On
the lower end of the range, fain grain network services 10Mbps to 1.25Gbps
supported by fgOTN and on the higher end with the support of 800Gbps and beyond
network services. ETSI ISG F5G has developed the OCN architecture to support
the connectivity access to the above-mentioned cloud services.

The OCN architecture supports the following network features:
1. Using network automation technologies via control protocols to automatically
select the Cloud Data Centre and the service connection provisioning. 2.
Different cloud application services may require different bandwidths ranges
from Mbps to Gbps. User may have different bandwidth needs, so the OCN
architecture supports flexible (fg)OTN containers with hitless bandwidth
adjustment. 3. OCN supports the service traffic isolation, which isolates user
traffic from each other, so no degradation in service quality. 4. The OCN
architecture provides scalable connection control and management, to support
the increasing number of service connections. 5. The OCN architecture supports
at least 99,999 % service availability. 6. The OCN architecture minimizes the
number of network layers, interfaces and protocols.

The OCN architecture uses Optical Service Protocol(s) (OSP) to support two
functions: • OSP connection control: Used for automatic creation, modification
(including hitless bandwidth adjustment) and deletion of (fg)OTN connections,
as well as fast (fg)OTN connection recovery from a network failure to satisfy
the service recovery performance requirements. • OSP service control: Use to
govern the service traffic between two OTN edge nodes, where the service
traffics are mapped into or de-mapped from (fg)OTN connection(s). The OSP
service control is to collect necessary service layer address information (e.g.
IP addresses), and to configure the (fg)OTN edge nodes, so that the service
traffic efficiently reaches the respective service destinations with the needed
service quality.

For the full details of the OCN architecture and the required protocol
functionality please refer to [2].

2. Actions:

It is not the intention of ETSI ISG F5G to develop the above-mentioned
protocol(s). The ETSI ISG F5G thinks the IETF is the most natural standards
organization to define those protocols. Therefore, the ETSI ISG F5G would like
the IETF to consider defining these protocols, which can then be referenced to
by future versions of the ETSI ISG F5G OCN architecture. Existing protocols
defined by IETF could be reused and extended to support the OSP connection and
service control functions. The ETSI ISG F5G is willing to cooperate on the
topic and is looking forward for the IETF’s reply.

3. Date of next meetings of the originator:

F5G-F2F#20, Nov 12-14, 2024, Jingdezhen, Jiangxi Province, China
F5G-F2F#21, Feb 25-28, 2025, Sophia-Antipolis, FR