Steven Chen Issue: India 2015
Article no.: 10
Topic: Get connected through a SDN-ized metro network
Author: Steven Chen
Title: VP, Product Management & Marketing
Organisation: UTStarcom
PDF size: 503KB

About author

Mr. Steven Chen has more than 18 years experience in telecommunication special in optical transport and broadband access area. He joined UTStarcom in 2003, working in product management, marketing, research & development groups. From Mar. 2012, he is serving as Vice President of Product management & marketing.
Before joining UTStarcom, he worked for ECI telecom optical division more than six years. Mr. Chen holds an MBA and B.S, System Engineering degrees.

Article abstract

SDN technology revolutionizes the way that service providers operate and meet rapidly evolving requirements of their customers, takes the network and services to the next level. By deploying SDN solution which can be a simple software upgrade to the existing equipments such as packet optical transport, MSAN and WIFI products your network can transition to the level of flexibility matching the transformation to cloud computing in IT, and hence be ready to efficiently deliver tomorrow’s network services. 

Full Article

Introduction
The rapid growth of mobile and cloud-based services, on-demand media streaming and social networking, as well as fast emergence of new applications and services, sets new requirements not only for considerably higher volumes of traffic, but also makes it essential for operators to be able to adapt their telecom infrastructure and respond very fast to deliver these dynamic changing services to users at anywhere and anytime. The ever-increasing number and importance of data centers are also pushing telecom operators to build more dynamic and automated metro network to support on-demand, instantaneous connectivity from data center cloud to end users.
‘Big data’ drives the rapid growth of network bandwidth demand that leads to considerable CapEx increase; however the revenue increase keeps at low levels for many years because fierce competition among telecom operators. In this hyper-competitive market, service providers are being forced to look for technologies and solutions that can help them bring new services to market, meanwhile grow their revenues, and reduce costs.
Software Defined Networks (SDN) is an emerging network technology that is rapidly gaining acceptance that allows the static networks of the past to evolve similar to the IT evolution to cloud computing. It is based on a network build of simple packet switching and transport nodes that are controlled by a central controller node that is able to program the packet switching and forwarding behavior of these nodes to match the requirements of the diversity of network services delivered on the network in real time.
SDN solution
SDN technology revolutionizes the way that service providers operate and meet rapidly evolving requirements of their customers, takes the network and services to the next level. By deploying SDN solution which can be a simple software upgrade to the existing equipments such as packet optical transport, MSAN and WIFI products your network can transition to the level of flexibility matching the transformation to cloud computing in IT, and hence be ready to efficiently deliver tomorrow’s network services.
The SDN solution should be based on an open structure and integrated with latest new technologies as following listed:
• Deploying an open SDN structure
SDN solution decouples of the control plane from the data plane, leading to virtualization of underlying network infrastructure (NFV). The centralized automated network operation through orchestration of virtualized network resources utilizes global knowledge of a network.

Fig 1. Smooth Transition to a SDN-ized Metro Network
A distributed hierarchical SDN Controller architecture provides a reliable solution for orchestration of abstracted underlying network resources, and management of open APIs for vertical integration of applications, and includes 2 major components:
1. The Central Controller performs automated network-wide topology management, status/traffic management, resource management, path routing calculation and other orchestrations based on its global network picture, and interfaces with external applications. The Central Controller also provides a set of standard open APIs which comply with OpenDayLight. The SDN vendor can provide a set of in-house designed APPs at startup. In addition, third party APPs can be developed based on the open API.
2. The Sub-Controller interfaces with a group of network elements and exchanges control commands and other data with underlying network infrastructure within its management domain. Currently SDN controller should support SNMP, TR069 and Qx interfaces to be compatible with existing network elements in the metro network. In future the SDN controller must also support the OpenFlow interface to control SDN white boxes.
• Software-defined Universal Packet Platform (SUPP)
With SDN solution operator can deploy highly efficient and flexible Software-defined Universal Packet Platform (SUPP) and access infrastructure, and optimize utilization of existing network resources. The SUPP product integrates OSI L2/L2.5/L3 forwarding functions into one hardware platform to dramatically reduce the complexity of Metro network. The SUPP provides pure OSI L3/L2.5/L3 packet switching and native packet flow-based forwarding. At the same time it supports flexible Ethernet-based services such as COE(connect oriented Ethernet)/VPWS, L2VPN and L3VPN including static and dynamic provisioning.

Fig 2. Software-defined Universal Packet Platform (SUPP)
The SUPP product inherits the advantages of traditional transport network, providing hierarchy OAM for on-line service performance monitoring and making the trouble-shooting and fault localization much more predictable and reliable. Full hardware redundancy and network sub-50ms protection provide Five-nines reliability. MPLS-TP based technology not only provides end-to-end QoS commitment but also scalability to different SLA requirements of customers. By support sync Ethernet and IEEE 1588v2 the SUPP product ensures that all the requirements related to network clock and time synchronization are met for 3G, HSPA, and LTE mobile backhaul network.
Powerful network management system (NMS) supports all classical functions of a network management including topology management, device management, fault management, performance monitoring, security management, and network provisioning. While it implements geographical redundancy (carrier’s choice) to support business continuity and high availability.
By deploying SDN controller operators can easily provide automated end-to-end service provisioning, bandwidth on demand, network design and optimization on a network-wide scale for a converged virtualized network which can incorporate packet optical transport solutions, broadband access products and integrate 3rd party equipment via Southbound interfaces.
• 100GbE implementation in the metro
Explosive growth in mobile broadband data traffic, data centers, and cloud-based applications are the catalysts behind significant traction of 100G deployments in the Metro networks. Service operators are accelerating the deployment of 100G but also looking carefully to manage their CAPEX and OPEX effectively.
Metro networks typically have shorter distances (over 95% are less than 40km) but much bigger number of nodes. 100G Coherent optical modules, used in the core and submarine applications, are simply too expensive, too big, and consume too much power for these type of networks.
The Software-defined Universal Packet Platform (SUPP) product shall deploy the next generation optical modules based on CFP2 form factor which is designed to fill this gap with much lower power and smaller profile. For instance, the maximum power specified for CFP2 module is about 8W, thus the total equipment power consumption is much less than legacy OTN equipments which use 100G Coherent optical modules.

Fig 3. 100G solution
By introducing 100G to metro network, the SUPP enables operator to drive up expensive OTN and reduce the quantity of traditional 10G equipments in the metro, thus allows service providers to simplify their metro networks and realize immediate cost, space, power and operational benefits. The implementation of 100G in the metro also brings better network latency and improved scalability that it has seen in deploying the technology in its long-haul network.
• Implementing L3VPN by centralized SDN controller
One of the most popular carrier services for Enterprise customers are Layer 3 IP VPN services. These IP VPN services enable the Service Provider to provide a wide variety of additional services to its customers because MPLS based IP VPNs are aware of the Layer 3 addresses at the customer locations, yet still provide the privacy inherent in Layer 2 VPN services.
With SDN controller the centralized software-based network control plane is decoupled from forwarding data plane, and enables a global view of the network, so that it’s natural to move the IP/MPLS control plane to the SDN controller. As illustrated in Figure 4 the SDN controller exchanges dynamic routing information with PE nodes and computes the routing path for the L3VPN.

Fig 4. IP/MPLS L3VPN with centralized controller
The centralized L3VPN solution based on SUPP with SDN controller provides a high reliability, secure IP VPN implementation with flexible networking modes, excellent scalability, and convenient support for MPLS QoS and MPLS TE.
The SDN based L3VPN solution obviously provides clear cost reduction by avoiding costly specialized IP service routers. While SDN Controller can take on complexity of L3 VPN provisioning and management by SDN controller which has a full picture of whole network and can easily support load balancing over multiple paths, improved QoS management and capacity and congestion management. SDN controller can set up on-demand L3VPN services such as telepresence session, business UC sessions, videocast and video distribution. At the same time the centralized L3VPN solution can drive IP VPNs deeper into the network by implementing in LTE/5G mobile network, and deeper enterprise branch roll-outs, remote educational network and inter-cloud connectivity.
• NFV mini-cloud to realize ‘all-in-one’ to simplify metro networks
NFV helps telecom operator to reduce the number of equipments with multi-vendors multi-technologies in its metro network, and migrate the network to the common platform of standard low cost computing servers, realize pay-as-growth network expansion in future.

Fig 5. All-in-one with centralized controller
Based on SOO SDN controller in Metro network the above NFV solution takes advantages of the position of powerful server of controller and implements the network function virtualization including WLAN access control (AC), L3VPN, telco CDN, DPI, wireless gateway, and even other functions provided by 3rd party software.
As a result, customers and operators gain unprecedented programmability, automation, and network control, which enable them to build highly scalable, flexible networks that readily adapt to changing business needs.

Summary
The future of networking will rely more and more on software, which will accelerate the pace of innovation for networks as it has in the computing and storage domains. SDN promises to transform today’s static networks into flexible, programmable platforms with the intelligence to allocate resources dynamically, the scale to support enormous data centers and the virtualization needed to support dynamic, highly automated, and secure cloud environments. The SDN solution provides a versatile and cost effective platform to take your network into the future and confidently deliver these next generation services based on SDN and NFV, thus helps operator to realize CapEx and OpEx saving, revenue increasing in the metro.