Description of the illustration cpt_pipes_ring_enable.gif

The figure is a diagram showing an E1 service trail, as described in the surrounding text. There is a primary path pipe at the top, an STM4 Ring in the center, and a secondary path pipe at the bottom. The primary and secondary path pipes use VC12 channels. The STM4 Ring connects 4 logical devices. The STM4 Ring has a provides relationship with the paths.