What is the ExpressRoute circuit composed of?

Each ExpressRoute circuit consists of two connections to two Microsoft Enterprise edge routers (MSEEs) at an ExpressRoute Location from the connectivity provider or your network edge. Microsoft requires dual BGP connections from the connectivity provider or your network edge – one to each MSEE. You may choose not to deploy redundant devices/Ethernet circuits at your end. However, connectivity providers use redundant devices to ensure that your connections are handed off to Microsoft in a redundant manner.