View relative latency to Azure regions from specific locations

In this tutorial, learn how to use the Azure Network Watcher service to help you decide what Azure region to deploy your application or service in, based on your user demographic. Additionally, you can use it to help evaluate service providers' connections to Azure.

Create a network watcher

If you already have a network watcher in at least one Azure region, you can skip the tasks in this section. Create a resource group for the network watcher. In this example, the resource group is created in the East US region, but you can create the resource group in any Azure region.

New-AzResourceGroup -Name NetworkWatcherRG -Location eastus

Create a network watcher. You must have a network watcher created in at least one Azure region. In this example, a network watcher is created in the East US Azure region.

New-AzNetworkWatcher -Name NetworkWatcher_eastus -ResourceGroupName NetworkWatcherRG -Location eastus

Compare relative network latencies to a single Azure region from a specific location

Evaluate service providers, or troubleshoot a user reporting an issue such as "the site was slow," from a specific location to the azure region where a service is deployed. For example, the following command returns the average relative Internet service provider latencies between the state of Washington in the United States and the West US 2 Azure region between December 13-15, 2017:

Get-AzNetworkWatcherReachabilityReport `
  -NetworkWatcherName NetworkWatcher_eastus `
  -ResourceGroupName NetworkWatcherRG `
  -Location "West US 2" `
  -Country "United States" `
  -State "washington" `
  -StartTime "2017-12-13" `
  -EndTime "2017-12-15"

The output from the previous command follows:

AggregationLevel   : State
ProviderLocation   : {
                       "Country": "United States",
                       "State": "washington"
                     }
ReachabilityReport : [
                       {
                         "Provider": "Qwest Communications Company, LLC - ASN 209",
                         "AzureLocation": "West US 2",
                         "Latencies": [
                           {
                             "TimeStamp": "2017-12-14T00:00:00Z",
                             "Score": 92
                           },
                           {
                             "TimeStamp": "2017-12-13T00:00:00Z",
                             "Score": 92
                           }
                         ]
                       },
                       {
                         "Provider": "Comcast Cable Communications, LLC - ASN 7922",
                         "AzureLocation": "West US 2",
                         "Latencies": [
                           {
                             "TimeStamp": "2017-12-14T00:00:00Z",
                             "Score": 96
                           },
                           {
                             "TimeStamp": "2017-12-13T00:00:00Z",
                             "Score": 96
                           }
                         ]
                       }
                     ]

In the returned output, the value for Score is the relative latency across regions and providers. A score of 1 is the worst (highest) latency, whereas 100 is the lowest latency. The relative latencies are averaged for the day. In the previous example, while it's clear that the latencies were the same both days and that there is a small difference between the latency of the two providers, it's also clear that the latencies for both providers are low on the 1-100 scale. While this is expected, since the state of Washington in the United States is physically close to the West US 2 Azure region, sometimes results aren't as expected. The larger the date range you specify, the more you can average latency over time.

Compare relative network latencies across Azure regions from a specific location

If, instead of specifying the relative latencies between a specific location and a specific Azure region using -Location, you wanted to determine the relative latencies to all Azure regions from a specific physical location, you can do that too. For example, the following command helps you evaluate what azure region to deploy a service in if your primary users are Comcast users located in Washington state:

Get-AzNetworkWatcherReachabilityReport `
  -NetworkWatcherName NetworkWatcher_eastus `
  -ResourceGroupName NetworkWatcherRG `
  -Provider "Comcast Cable Communications, LLC - ASN 7922" `
  -Country "United States" `
  -State "washington" `
  -StartTime "2017-12-13" `
  -EndTime "2017-12-15"

View available countries/regions, states, cities, and providers

Data is available for specific Internet service providers, countries/regions, states, and cities. To view a list of all available Internet service providers, countries/regions, states, and cities, that you can view data for, enter the following command:

Get-AzNetworkWatcherReachabilityProvidersList -NetworkWatcherName NetworkWatcher_eastus -ResourceGroupName NetworkWatcherRG

Data is only available for the countries/regions, states, and cities returned by the previous command. The previous command requires you to specify an existing network watcher. The example specified the NetworkWatcher_eastus network watcher in a resource group named NetworkWatcherRG, but you can specify any existing network watcher. If you don't have an existing network watcher, create one by completing the tasks in Create a network watcher.

After running the previous command, you can filter the output returned by specifying valid values for Country, State, and City, if desired. For example, to view the list of Internet service providers available in Seattle, Washington, in the United States, enter the following command:

Get-AzNetworkWatcherReachabilityProvidersList `
  -NetworkWatcherName NetworkWatcher_eastus `
  -ResourceGroupName NetworkWatcherRG `
  -City Seattle `
  -Country "United States" `
  -State washington