Transport infrastructure
SANET infrastructure is based on dark fibre – leased from fibre providers on inter-city level and self-owned on metropolitan level.

Transmission of N x 100 Gb/s channels over upto 150 km of dark fibre is accomplished by coherent PtP DWDM system Infinera CloudXpress CX100E. Two 100 Gb/s channels are currently in production, but the installed technology enables SANET to increase backbone capacity to 5x100Gb/s just by purchasing corresponding licenses without the need to acquire and install any additional equipment.

SANET backbone is built on Ethernet technology with intelligent shortest-path L2 packet forwarding provided by TRILL protocol. This setup enables native L2VPN services in the transport network without the need to implement MPLS. All network POPs are equipped with Huawei CloudEngine 8860 TRILL switches with 3.2 Tb/s of capacity.

Network topology
SANET infrastructure consists of multiple interconnected fibre rings, which create a highly resilient network. In case of fibre cut, traffic is immediately rerouted over the remaining links to ensure high reliability.

Internet infrastructure
At IP layer, SANET backbone forms a single ethernet segment, where TRILL protocol performs shortest-path routing for all L2 packets. Thus for IP, the distance between all POPs is exactly 1 hop, which means there’s no need to run any IGP protocol at L3. Exchange of routing information is done solely by BGP protocol.