SD-WAN: The secret weapon against network challenges

Software Defined Networking (SDN) is an approach to network management that enables dynamic and programmatically efficient network configuration. It improves network performance and monitoring in a manner akin to cloud computing than traditional network management.

SD-WAN is an acronym for Software Defined Wide Area Network. SD-WAN simplifies the management and operation of WAN by decoupling the networking hardware from its control mechanism. SD-WAN identifies with SDN and is utilised by a large number of organisations to interface their business premises to a remote system through the web or cloud. In SD-WAN, SDN principles i.e., to build and offer centralised intelligence, control, security and performance are used.

In the earlier networks, just connecting users to the data centre was a priority. The networks were not application aware (in application aware technology, key applications are tagged and prioritised).

Today’s network demands any time anywhere connectivity with mission critical latency. SD-WAN provide flexible connectivity and ease of management.

MPLS technology is not application aware. Its reach is less than the internet and is expensive.

Higher network SLAs, transport independent virtual network, impregnable security of blockchain type, enhanced end user experience, zero touch and ease of cloud adoption, real time active load balancing and WAN optimisation are the advantages of SD-WAN technology.

The high performance SD-WAN solution allows the organisations the ability to easily add and deploy more network functions without the complexity of multi vendor interactions.

With SD-WAN building blocks, customers have choice regarding platform, last mile/WAN, security and multi cloud. In MPLS, customers don’t have such choice.

SD-WAN orchestrated low touch/zero touch branches enables enterprises to centrally control their WANs, easily manage branches and deploy appliances with no IT staff needed at remote branches. Fast response to WAN changes is ensured. Time to deploy new sites, services or bandwidth will be decreased.

Monitoring and alerts with enterprise view, dashboards and comprehensive reports are other features which are provided by orchestrator building blocks.

Reasons for enterprises for moving to SD-WAN

1. Higher Network uptime: Freedom from millisecond failover, load balancing, transport independent overlay network

2. Enhanced end user experience: Accelerated application response, application level priority, application QOS, high capacity internet links at reduced cost

3. Impregnable security: IPSEC (Internet Protocol Security) with blockchain type security firewall with deep packet inspection, next gen firewall IDS (Intrusion Detection System) /IPS (Intrusion Prevention System), web filter etc.

4. Zero touch provisioning and deep analysis: Orchestration- simplifies management, operations automation - zero touch provisioning/ updates, fault/ alarm management and diagnostics, dashboards, comprehensive reports including application reports

5. Ease of cloud adoption: application can reside in multiple public/ private clouds

6. Reduced total cost of ownership: unified hardware for router, firewall, IDS (Intrusion Detection System), WAN operation and load balancer, UTM (Unified threat management), DNS (Domain Name Server), antivirus NMS

WAN technology evolution

1. Routing protocol limitation

a) No end to end visibility as they work mostly on next hop concept/updates

b) Border gateway protocol (BGP) was discovered in 1994 and has limitations of no performance based visibility/routing, no application awareness, no load balancing. Overlay network is the solution.

c) OSPF (Open Shortest Path First) protocol was discovered in 1989-if one link is "flapping" every few seconds, then SPF updates would be very high informing every other router for every flap- overlay can solve this issue.

2. MPLS- is available from late 90’s till now has limitations of traffic engineering and on top of tech issues, it has issues of provisioning delay, SP (Seamless Protocol) agnostic network, geographic reach with limited bandwidth.

3. Routers don’t have much security features

4. Applications earlier were only data but now with video and voice, the networks have to be agile with virtual software based network functions.

5. Fragmented evolution of hardware devices- load balancers, WAN optimizers- with increased point of failures and have high AMC costs.

6. Unified overlay SD-WAN with VNF (virtualisation of network function) is future proof.

SD- WAN technology trends

1. Granular control of data with intelligent SD-WAN

Multi path security transmission introduces a blockchain level of security for transmission between data paths. By distributing packets over multiple active links, it is ensured that all data packets are not seen on any one ISP, making it impossible to put together the data stream. MPSEC technology ensures that all routes are fully utilised and bandwidth maximised. Should any one path go down, the data is automatically re-routed to the other paths, without restarting the session or dropping packets, making a real time SD-WAN.

2. Blockchain type transmission security

3. Optimal link utilisation without traffic duplication

4. Scalability

5. Inbound load balancing

6. Managed SD- WAN

7. Smart Edge with independent data plane

8. Byte level WAN optimization

Reduction of traffic between 40 90 per cent. Filters traffic such as advertisements, music, attachments etc. Compresses data to 2 per cent of original size. Deduplication provides up to 60 times average data reduction

9. Freedom from network obsolescence

10.Selective encryption data transmission

11.Dynamic/rotating IP address failover technology

Way forward

In SD-WAN the customer can leverage the various types of connectivity like MPLS, internet, FTTH, 4G, VSAT etc. and can achieve a very highly reliable connectivity. Traffic can be routed on different paths based on the application requirements.

Our country’s network challenges viz. frequent fiber cuts due to road digging activities, delay in fiber restoration due to permissions to be obtained, degraded fiber performance due to more joints, network congestion necessitate innovative solutions. SD-WAN emerges as a game changer in this context, giving intelligent traffic management and high availability.

BSNL and ECIL signed a three year MOU to collaborate on SD-WAN. ECIL would be promoting proper supply chain management of the SD-WAN which will be deployed by BSNL in their network.

In June 2023 Vodafone Idea (VI) launched the SD-WAN offering aimed at modern business and companies seeking cost- efficient advanced security solutions.

In De 2022, JIO bagged a deal to deploy SD-WAN solution across IOCL’s 7,200 retail outlets. This will be one of the largest deployments of SD-WAN solutions in India across any industry.

Over the next few years, the fast evolving SD-WAN market is expected to see rapid growth.

(The author is a former Advisor, Department of Telecommunications (DoT), Government of India)