Azure ER peering location and Azure Region

Shola Lawani 531 Reputation points Microsoft Employee

Hello Experts,

Are there any latency considerations when choosing an azure ER peering location and mapping that to an Azure Region?

So for instance if I'm setting up an Azure infrastructure in Canada Central, is the latency significantly reduced if the peering location is in Toronto and not Quebec?

Azure Virtual Network
Azure Virtual Network
An Azure networking service that is used to provision private networks and optionally to connect to on-premises datacenters.
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Azure ExpressRoute
Azure ExpressRoute
An Azure service that provides private connections between Azure datacenters and infrastructure, either on premises or in a colocation environment.
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  1. GitaraniSharma-MSFT 46,931 Reputation points Microsoft Employee

    Hello anonymous user ,

    Azure regions are global datacenters where Azure compute, networking and storage resources are located. When creating an Azure resource, a customer needs to select a resource location. The resource location determines which Azure datacenter (or availability zone) the resource is created in.

    ExpressRoute locations (sometimes referred to as peering locations) are co-location facilities where Microsoft Enterprise Edge (MSEE) devices are located. ExpressRoute locations are the entry point to Microsoft's network – and are globally distributed, providing customers the opportunity to connect to Microsoft's network around the world. These locations are where ExpressRoute partners and ExpressRoute Direct customers issue cross connections to Microsoft's network.

    In general, the ExpressRoute location does not need to match the Azure region. For example, a customer can create an ExpressRoute circuit with the resource location East US, in the Seattle Peering location.

    While they are not related, it is a good practice to choose a Network Resource Provider geographically close to the Peering Location of the circuit.

    We have seen latency/bandwidth issues when the Azure ER peering location and Azure Region differs. You can refer the below article to see such an example of West US 2 Azure region where the latency to Seattle Peering location is less compared to regions such as West US or Central US (NOTE : Seattle peering location is located in West US 2 Azure region):

    Hence, it would be a good idea to choose peering location Toronto and not Quebec if you are setting up an Azure infrastructure in Canada Central to ensure reduced latency. But as I mentioned before, the ExpressRoute location does not necessarily need to match the Azure region.

    Kindly let us know if the above helps or you need further assistance on this issue.


    Please "Accept the answer" if the information helped you. This will help us and others in the community as well.

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  1. Romain 1 Reputation point

    Hello @GitaraniSharma-MSFT ,

    Thanks for your insight above, very informative!

    How do I programmatically (using Azure API/Python SDK) list the compatible Azure Regions in order from the closest to the furthest when selecting a Peering Location? And vice versa.

    For example:

    1. If I select Toronto, the API/Python SDK would return a list starting with Canada Central, Canada East, Central US, etc...
    2. If I select Canada Central, the API/Python SDK would return a list starting with Toronto, Toronto2, Montreal, etc..


    ExpressRoute locations
    Atlanta, Chicago, Chicago2, Dallas, Denver, Las Vegas, Los Angeles, Los Angeles2, Miami, Minneapolis, Montreal, New York, Phoenix, Quebec City, Queretaro(Mexico), Quincy, San Antonio, Seattle, Silicon Valley, Silicon Valley2, Toronto, Toronto2, Vancouver, Washington DC, Washington DC2

    Azure regions
    East US, West US, East US 2, West US 2, West US 3, Central US, South Central US, North Central US, West Central US, Canada Central, Canada East

    Thanks & Regards,

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