ExpressRoute Connection Models – Intersite Connectivity

The type of connection from on-premises to the Azure cloud using ExpressRoute is determined using the connection models. You have four models available: co-located at a cloud exchange, point-to-point Ethernet connection, any-to-any (IPVPN) connections, and ExpressRoute Direct. These offerings are provided by the connectivity provider, and you can pick the one that suits your requirement. Now, you will learn the difference between these connection models.

Co-located at a Cloud Exchange  This model is ideal if you are co-located in a facility with a cloud exchange. You can then order a virtual cross connection using your co-location provider’s Ethernet exchange. Layer 2 cross connections and managed layer 3 cross connections are supported for establishing connectivity between the Microsoft cloud and your co-location facility.

Point-to-Point Ethernet Connections  Connectivity from on-premises to the Microsoft cloud can be established using point-to-point Ethernet links. Layer 2 connections and managed layer 3 connections are supported for establishing connectivity.

Any-to-Any (IPVPN) Networks  You can extend your on-premises by integrating your WAN with the Microsoft cloud. Once established, the Microsoft cloud will resemble another branch office in your WAN. Managed layer 3 connectivity is supported. ExpressRoute features and capabilities are the same across all the aforementioned connectivity models.

ExpressRoute Direct  ExpressRoute Direct offers the capability to use the peering location spread across the globe to connect with the Microsoft global network. An active-active connectivity with dual 100 Gbps or 10 Gbps connectivity is offered by ExpressRoute Direct. Further, it provides additional features such as faster ingestion of larger datasets to Azure Storage and Cosmos DB, isolation of connectivity, and granular allocation of circuit distribution within the organization.

With that we are concluding the Azure to on-premises section. Now you are familiar with the connectivity methods for establishing communication between Azure-to-Azure and Azure to on-prem. Let’s combine all the methods we have studied so far to create an intersite connectivity architecture. This architecture is common in enterprise environments.