circuit layer

In the layer model of the three-layer CCITT architecture (G.sna1) for transport networks, the line layer forms the top layer. In it, the line networks - without service-specific switching functions - are configured to support the telecommunications services. Below the line layer is the path layer, which provides the line layer with the data rates for the DS connections at 155 Mbit/s, 45 Mbit/s, 8 Mbit/s, and 2 Mbit/s.