VMware Velocloud SDWAN: Dynamic Multi-path Optimization (DMPO) Monitoring

As we discuss on the basics of the Vmware Velocloud SDWAN, Now we are going to talk about the components of Vmware Velocloud SDWAN solution 

As you know the next generation networks and the software defined approach, Velocloud also provide you the centralized control with the VeloCloud Orchestrator. The Orchestrator provides centralized configuration and real-time monitoring with the provisioning of virtual services across Edges.

There are lot of various solution components and the features in the VMware Velocloud SDWAN solution and we will discuss all these features one by one to understand more in details. 

In this article we will discuss about the Dynamic Multi-path Optimization (DMPO) Monitoring only and will come up all one by one in our next article of Velocloud SDWAN solution. 

Dynamic Multi-path Optimization (DMPO)
In the topology of the Velocloud SDWAN solution, the Edge device named as VeloCloud Edge (VCE) and the traffic flow towards VeloCloud Gateway (VCG). So the DMPO is basically  process and forward data traffic between various VeloCloud Edges (VCE's).

In the environment like spoke to spoke and hub to spoke, these DMPO tunnels are being created between these VCE's. Make sure you remember VCE's ( Velocloud Edge device). 

Fig 1.1- Dynamic Multi-path Optimization (DMPO)

Now the questions, with these tunnels what are we maintaining .. Is that data traffic only ?

The Answer is we have multiple tasks within the DMPO, Let's discuss

As we set up WAN link like MPLS/VPLS/Internet on VCE's, it establishes DMPO tunnels with one or more VCGs and runs bandwidth test with the closest VCG. The bandwidth test is performed by sending short burst of bi-directional traffic and measuring the received rate at each end. 

Since the VCG is deployed at the Internet Points of Presence (PoPs), it can also identify the real public IP address of the WAN link in case the VCE interface is behind a NAT or PAT device. 

DMPO doing continuous, uni-directional measurements of performance metrics - loss, latency and jitter of every packet on every tunnel between any two DMPO endpoints, VCE or VCG. Velocloud per-packet drive allows independent decisions in both uplink and downlink directions without introducing any asymmetric routing. DMPO uses both passive and active monitoring approaches. 

Ok what about if we lost packets in between ?

DMPO tunnel header contains additional performance metrics including sequence number and timestamp, thus enabling the DMPO endpoints to identify lost and out-of-order packets, and calculate jitter and latency in each direction. The DMPO endpoints communicate the performance metrics of the path between each other every 100 ms.

WoW.. good Now as we said in the above statement communication between DMPO endpoints in every 100 ms. Now when there is no traffic between these end points for more than 100 ms ?

An active probe is sent every 100 ms and, after 5 minutes of no high priority user traffic, the probe frequency is reduced to 500 ms. This comprehensive measurement enables the DMPO to react very quickly to the change in the underlying WAN condition, resulting in the ability to deliver sub-second protection against brownout and blackout in the WAN.

Ok what else ? 

DMPO identifies traffic using layer 2 to 7 attributes like VLAN, IP address, protocol, and applications. VeloCloud performs application aware per-packet routing based on  Policy configurations which we defined on the orchestration and real-time link conditions. 

Although we have system built defined policies can be used without creating any manual policies. It was said by Velocloud that more than 2500 applications policies defined based on the behaviour and the priority set. 

DMPO finds brownout or blackout condition within 300-500 ms and immediately drive traffic flow to protect the application performance, while ensuring no impact to the active flow and user experience.

It also learn the behavior and the nature if the applications and forward the traffic based on first packet of the application by caching classification results. This is necessary for application-based redirection. The applications which are internet based can bypassing the DMPO tunnel, while backhauling Office 365 to the Enterprise regional hub or data center.