China Unicom SDN Practice in WAN
Lv Chengjin/Ma Jichun, China Unicom What Will Operator SDN Do?
Two development directions
Software- 1. Cloudify traditional services defined Operator networking (SDN) 2. Develop new network services
Data center (DC) SDN
Highly integrated with cloud services, DC SDN focuses on support for traditional service evolution.
DC SDN technologies in data centers are mature, and cloud providers' and vendors' solutions are numerous and diverse. WAN SDN
WAN is the basic capability of operators. SDN focuses on developing new services.
The implementation solutions are complex and different between operators. Problems to Be Tackled by WAN SDN
Operator WAN complexity •Individual networks have large capacities, accommodate a great number of subscribers, Complex networks run various types of services, and use complex techniques. •Devices are numerous and come from various vendors, posing high requirements on inter-vendor Complex devices interworking.
Complex services •The controllability of common services is low, posing high requirements on solution adaptability.
SDN implementation feasibility •There are a relatively few cases of SDN being successfully deployed on large Insufficient cases WANs. •The live network service process is complex and highly tailored, which makes it Highly tailored difficult to generalize.
Deployment policies are important
SDN policies for China Unicom's IP bearer network: Use new service development to promote network reconstruction and gradually implement SDN on the entire network. From IP Bearer Network to Industry Internet
China Unicom IP Bearer Network A China Unicom Industry Internet (CUII) Changes in the technical environment:
Customer group Enterprise Mature cloud computing: Enterprise IT infrastructure VICs cloudification
Services Rapid IoT development: Increasing demand for
MPLS VPN leased lines connections
Characteristics Usage scenario changes:
Virtual private network Cloud interconnection: DC → DC
security isolation Cloud access: Enterprise → DC, device → DC
IP statistical Requirement changes: multiplexing Performance Efficiency Price Fast provisioning Light load Low latency Differentiation High reliability Flexible Short lease adjustment Introducing SDN to Implement New Services
Self-Services Various Service Attributes Selected Indicator Supported Attributes • Order online: Place an order online. Bandwidth Assured, best effort • Quality on-demand: Match customer service guarantee requirements against quality assurance levels Latency Shortest, best effort Service rollout on service requirements. Monthly/day, self-defined • Visualized interface: The map mode can be time Service access selected to display network topology and VLAN,VXLAN routing paths. mode Service priority High, medium, low level Intelligent Path Selection Customer service Diamond, gold, silver, • Shortest delay: The minimum transmission assurance level copper latency is implemented.
Service Source Node Sink Node Bandwidth Utilization Traffic Curve Operation • High availability: E2E route separation is Adjust Service1 北 北 北 北 10Mb 50% View bandwidth
Adjust supported. Service2 北 北 北 北 100Mb 80% View bandwidth
Real-Time Provisioning • Dynamic configuration: Configurations are rapidly delivered and implemented. • Flexible duration: The service provisioning time and service duration can be selected as needed. SDN Implementation Architecture
General Roadmap API Portal Industry Internet Unified service SDN Solution orchestration and Inter-network Service Orchestration and Service management and inter- Openness Platform Layered Independent domain architecture networks and service services Apps provide APIs and domains, each with GUIs. complete functions The controller
Public Public Internet OSS/ controls devices. Hierarchical App ...
decoupling to ensure BSS Internet scalability Industry Multi-vendor Controller Professional networks are Intra-network support independently and intra- The controller and implemented, and domain network devices are capabilities are gradually services Network decoupled, and integrated device multi-vendor devices are supported. SDN Control Solution Selection
Service layer
Refine service requirements and design products API GUI
Abstract service model and unify Service App parameters
Define external interfaces Control Controller Apps are self-developed, ensuring service flexibility
Controller layer Bearer network Adapt the control model to multi- vendor devices Forwarding
TE tunnel Deliver service paths L3VPN/VLL
Collect configuration and topology information The controllers are mature products of partners Model Driven
Northbound interface model of the controller Objectives: Define functions and Defined China Unicom L3VPN shield differences. YANG YANG model models Service model definition: YANG Topology management YANG model SR-TE YANG model
Southbound interface model of HA model the controller Objectives: Control devices of multiple vendors. Device interface: NETCONF Service Model (YANG Model)
Topology L3VPN Model L3VPN Model SR-TE Model Management HA Model Extension Model
Creates, deletes, Creates, deletes, and queries VPN- queries, and SVC instances. modifies tunnel Queries Modifies and instances based on information about Creates, deletes, extends QoS China Unicom's TE all network and queries sites profiles. scenarios. topologies on the and site-network- (Tunnels can be controller. access. created separately Synchronizes or for VPN services.) service Creates, deletes, configurations and modifies static during a routes. master/backup controller switchover. Modifies BGP peer Creates, queries, Queries and Provides the RPC relationships. and deletes VPN modifies topology, request model for and TE tunnel link, and node path computation. Assigns, maintains, bindings. information. adds, deletes, and queries resource pools. Network Technology — SR
Segment routing (SR): a source routing protocol that optimizes IP and MPLS network capabilities.
Based on label switching, SR extends existing IGP protocols, controls routes on the source node, and supports a variety of functions, including TE and FRR.
The combination of SR and SDN provides obvious advantages
Highly efficient Simple Scalable Programmable • A great number of • SR FRR implements • Individual flows on a • The SDN controller stateless TE protection switching network are controlled, programs the connections are for less than 50 ms, which improves infrastructure network supported, and SR involving merely a few network scalability. to implement supports inter-domain protocols. Application-based fine application solutions, which are control capabilities are requirements, which implemented on supported. allows E2E flow-based physical networks, program policies to be virtual networks, and enforced. servers. SR Usage
Usage Resolved Issues
Devices of different vendors run SR-TE and SDN are jointly used in inconsistent label distribution protocols. a multi-vendor environment for the Vendors implement BFD differently. first time. The SBFD solution is to be optimized in Differentiated service requirements Uniform mode. are met, and specific paths are selected. SDN SDNcon控制器troller 2 PEs and Ps of different vendors can communicate using SR-TE and 1 4 7 run SR-TE services. 6 5
16005 16007 PKT Collaborating with Public Cloud Service Providers
Collaborate w i t h p u b l i c c l o u d Subscriber service providers to provide hybrid cloud connections. Application Application Configuration Public cloud Cloud Private cloud Team up with public cloud partners to resources connection resources implement VPN connections between public clouds and customer infrastructure. Public VPN Private Define a public cloud interface and transfer cloud cloud connection parameters to implement online Parameter transfer Parameter transfer handling and automatic provisioning.
Interfaces have been developed and are being tested in collaboration with mainstream public cloud service providers Implementation Status
Implementation completed: Main technical solutions and specifications (service, technical, and interface specifications) App function development in phase 1 and phase 2 Joint commissioning testing in the laboratory Online verification test Commercial launch of services in a total number of 35 cities across China will be completed in the near future.
P5 CE PE1 PE5 CE 1 CE 5 P1 P3 P7 PE2 CE 2 PE6 CE 6
P6
CE 3 PE3 PE7 CE 7 P2 P4 P8 CE 4 PE4 CE 8 PE8 Our Experience
The following aspects help implement WAN SDN:
1. Find new services suitable for SDN to promote network transition to SDN.
2. Follow the multi-layer decoupling design to ensure flexible architecture adaptation.
3. Customize a solution based on operator networks, instead of requiring mandatory commonality.
4. Select suitable partners and closely cooperate with one another to optimally utilize the advantages of each. Thank you!