Huawei's approach to an Open Central Office:

Bringing Data Center Economies to Telecom Industry

Authors: Dr. John Strassner, Ayush Sharma, Sandeep Dhingra

Table of Contents

1. Introduction .................................................................................................................................... 3

2. Problem Statement.......................................................................................................................... 3

3. Architecture..................................................................................................................................... 3

4. Business Benefits ............................................................................................................................. 4

1. Introduction

Huawei’s Central Office Initiative is a comprehensive architecture, realized by a series of Proof-of-Concept

demonstrations, for bringing data center economies of scale to telecommunications. Our novel Central Office

solution uses Open Standards and Open Source as a foundation of its architecture that enables virtual functions,

such as vCPE, vIMS and vBNG, as well as services, such as CDN and 4K TV, to be implemented in a robust,

scalable, and extensible manner. Central Office is a transformation enabler; this facilitates new functionality to

be gradually phased into a system to support the business needs of the organization, regardless of whether that

functionality is in the access layer or (for example) the metro layer.

2. Problem Statement

The explosion of different types of services, each with its own different requirements, mandates better resource

utilization and more freedom in orchestrating network services. A traditional telecom central office can be

viewed as a sophisticated switching center, connecting subscriber residential, mobile, and business traffic. A

traditional Central Office co-locates a complex collection of equipment that typically have rigid interconnections.

This makes changing existing services, and especially introducing new services, a complex and lengthy process.

More flexible control of network resources and services is needed.

Key problems faced by Service Provides include creating service agility, reducing OpEx, and reducing CapEx.

Central Office provides a holistic combination of SDN and NFV to solve these problems. SDN offers

programmability, while NFV concentrates on separating monolithic functions into a set of agile services. The

Huawei Central Office initiatives uses SDN and NFV to move the functionality of a traditional telco central office

to a cloud-enabled data center. This transforms switching to a hosted service, which enables the assets

previously dedicated for switching to be used for other, more strategic purposes. It also provides cloud elasticity

for local and regional business customers. For example, dynamic service function chaining, and incorporation of

virtualized functions, support service agility, lower time-to-market, and provide access to new revenue streams.

3. Architecture

Huawei's Central Office initiative, based on software

defined data center technologies, combines the benefits

of SDN and NFV to bring scalability, flexibility, and

extensibility to the functionality required by the modern

day Central Office. Virtualized infrastructure is managed

by SDN; NFV enables services to be composited by

separating traditional monolithic network functions into

agile services that are chosen based on context-aware

policy rules. A conceptual architecture of Huawei's

Central Office initiative is shown in Figure 1.

Figure 1. Huawei Central Office Conceptual Architecture

The bottom two layers connect physical and virtual infrastructure through a set of cloud interfaces to the

“brains” (i.e., the model-driven autonomic framework) of the Central Office. Central Office abstract physical and

virtual compute, storage, and networks, enabling a seamless transition to using data center technologies.

The Cloud System Interfaces exemplify Huawei’s commitment to openness. Open standards, such as Open Flow

and Netconf, are combined with open source, such as ONOS, to provide a comprehensive and holistic solution.

The “southbound” interfaces of the Cloud System enable different types of virtualized systems (e.g., bare metal

KVM systems) or packaged solutions (e.g., FusionSphere), to be used. Central Office enables different control

systems, such as an ONOS controller, to be used without changing the other components in the architecture.

Similarly, the “northbound” interfaces of the Cloud System connect the raw functionality provided by physical

and virtual components to a cloud system, such as OpenStack.

The heart of the Central Office system is its model-driven autonomic framework. The model is used as a

common vocabulary, enabling the syntax and semantics of different types of operational, management, and

performance data to be understood. This is complemented by analytics and Big Data functionality that is

implemented as an integral part of the system’s control loop. Analytics is used to understand and predict where

problems can occur, and proactively fix them before SLAs are violated. Big Data mechanisms are used to

efficiently extract appropriate data, trends, and semantics from the wealth of data available to the Central

Office system. More importantly, this improves the speed at which the services and resources provided by the

Central Office can adapt to changing user needs, business goals, and environmental conditions. Value-added

services, such as service orchestration, realtime traffic analysis, and other OSS/BSS functions, will be provided by

Huawei. These are based on the open and modular Central Office platform; hence, third party applications can

plug into this platform to provide their own solutions.

The next two layers creates resource and service building blocks from the infrastructure. These building blocks

form reusable templates that help construct a range of functions for building business services (e.g., load-

balancing, firewall, DPI, and traffic steering). Policy rules are used to direct how these building blocks are used to

create more powerful business services (e.g., L3VPN, vE-CPE, vCDN, and 4K TV) for consumption.

The final layer of Central Office provides graphical and textual user interfaces to access its functionality. Both

use the same RESTful APIs. In addition, a novel policy language interface that provides traditional as well as

intent-based policies will be added in the near future. All will be connected to developer communities.

4. Business Benefits

Huawei is combining Open Standards and Open Source with modern DevOps practices to provide a robust and

extensible platform for using business needs to drive network resources and services, contextually. This enables

time-to-market, agility, and OpEx reduction to be directly addressed in a coordinated and scalable manner.

A major strength of Huawei’s Central Office platform is its ability to support phased roll-out of business services.

It can facilitate the gradual transformation of the traditional central office into a dynamic, cloud-based, data

center. Huawei Central Office seamlessly integrates legacy, NFV, and SDN technologies under a policy-driven

management and orchestration model-driven framework. This takes advantage of a growing ecosystem of

developers and partners.

Huawei plans to demonstrate progressive use cases in the next few months, starting with L3VPN and virtual

enterprise CPE. Significantly, these will be demonstrated on COTS severs using Open Standards and Open Source.

The first such demonstration will be in the Open Networking Summit in June 2015.

Looking ahead, Huawei will remain committed to open innovation and cooperation, creating greater value for

our customers, advancing the ICT industry, and ultimately contributing to the building of a better connected

world.