Recently I went on a journey testing the latency of the Azure dark fiber backbone between data centers.  This is crucial for a global Dynamics 365 Finance and Operations (“FinOps”) implementation.  In general bandwidth can be purchased but latency is hard to influence.

There are some resources online which provide latency numbers which seem to hold somewhat accurate still, but I wanted the latest latency numbers to use in my analysis.  Each end-user location could determine which Azure data center was closest by using Azurespeed.com.  Next I referenced a Microsoft blog to test latency between Azure data centers, so that I could prove the benefit of Azure Express Routes to the nearest/lowest-latency data center, then routing traffic to the FinOps instance would be the best approach.  Here is what I did-

1. Created a vNet with two subnets in the region to host FinOps
10.20.1.0/24   vNet
10.20.1.0/26   Resources subnet
10.20.1.192/26 Gateway subnet
2. Created a VPN Gateway in the region to host FinOps – this takes a long time to deploy

3. Created vNets with two subnets in every destination region each region with a different number for variable ‘n.’

10.20.n.0/24   vNet
10.20.n.0/26   Resources subnet
10.20.n.192/26 Gateway subnet
4. Created VPN Gateways in every destination regions
5. Created VPN connections – connections representing both directions must be created, both origin to destination and destination to origin.
6. Created virtual machines (VM) – Deployed the first one manually then created a template for the other regions to make for a faster deployment which could guarantee consistency.
7. Configured the Network Security Groups on all virtual machines
Limited RDP traffic to my IP and inter-region IPs   {MyIP},10.200.0.0/16
Allowed PsPing traffic on port 81
8. Did testing using psping (iperf is an alternative)
On the origin:  psping -f -s 10.20.1.4:81
On the destination:  psping -l 8k -n 1000 -f 10.20.1.4:81

Example output from PsPing from Korea Central to East US2:

Latency has always been a critical component of any AX or D365FO implementation.  Now that it is hosted by Microsoft we have several tools to test network performance before we deploy.