SD-WAN VeloCloud Introduction
Before SD-WAN was deployed, there were various challenges on WAN side of any Enterprise environment.Before SD-WAN, the Enterprise WAN was very expensive, complex and very inefficient.
As we have already discussed a lot what all the drawback are, shortcoming and challenges of traditional WAN, but here are some issues:
- Slow Deployment times of Branches
- Backhaul for Cloud services because traffic has to go to DC for authentication and then to cloud for application access
- Expensive private lines like Lease line, PTP, MPLS etc.
- Constrains of Choice of link if site has more than two links.
But when SD-WAN is deployed across Enterprise WAN, there will be following benefits:
- Deploys in days: Branch WAN can be commissioned in days instated of Months, because of central orchestrator, it is used to centrally configure all policies and then these policies are pushed to all Branch SD-WAN device as per application requirement
- Optimized Cloud Access: In this Branch can be accessed directly from cloud, while controlling all security policies required to access application hosted in cloud.
- Use of Multiple transport: With SD-WAN if the site has multiple links, like (MPLS, LTE, Internet, 4G, 5G, Broadband) etc., all these multiple link can be efficiently utilized parallely.
- Assured Application performance: Due to SD-WAN, intelligence in WAN and Granular policy support, all application hosted on Cloud or in Data Center gives the assured performance as per expectation.
Business benefits of VeloCloud
Below figure explains the summary of Business benefits of SD-WAN solution provided by Velo Cloud.
VeloCloud is the SD-WAN solution of VMware which supports the data plane services in the cloud as well as on on-premise deployments. This solution enables policy based access to application hosted in cloud as well as datacenter. The overall preview of VleoCloud Cloud delivered SD-WAN solution as given below:
VeloCloud SD-WAN Advantages:
Following is the NSX SD-WAN advantage over traditional WAN, as we know that NSX SD-WAN solution is logical overlay network:
- That is independent of any service provider
- It can encompress any WAN transport weather it is Private line, Public, or LTE , provides assured application performance over any link by continuous monitoring , dynamic per packet steering – decision.
- It can easily works between any two SD-WAN nodes which are deployed on Branches or datacenter and is even called as Edges
- These can be appliances or virtual appliances running on x86 server which can be deployed on on-prim or cloud.
- This overlay can be extended to any cloud or even to any cloud POP or DC with help of cloud gateways
- It also provides multi-tenant support while the help of central Orchestrator with single pane of glass for entire SD-WAN solution
Other advantages are discussed on below figure:
How VeloCloud provides Assured Application Performance:
In case of UDP: In this it uses on demand packet duplication , that is if you have two link , the same packet is sent to both link twice , one on each other , and if you have one link , the same packet is sent two times on single link back to back , because on internet , packet can be dropped due to tail drop feature , so when you send two packet back to back it is very unlikely that if one packet gets dropped , other may also drop , on most cases if one packet is dropped , second packet is not dropped and if you receive both packet than by logic it will drop second one keeping the assured application performance on video.
In case of TCP : As we are aware that if packet is dropped , window of TCP gets adjusted and some time it is so small that we can observes the application performance issue causing more than 2% of packet loss.
To avoid this VeloCloud the mechanism, called NAK (Non agreement acknowledgement), in which if it sees that certain frames are missing so it starts using NAK , and informs the other end that I am missing let’s say frame ( 6, 8 , 9 ) please send these frames again , and other end will send these frames instead of reducing the Window size.