The channel segments of TSY2-047 PDH and SDH systems in the quota are tested at the optical terminal (end station).

1, when a new SDH or PDH system is built, this quota is used when the new system is directly carried on an external optical cable instead of a wavelength division system.

2.SDH system consists of TM, ADM, REG, DXC and other network elements. Generally speaking, end stations refer to TM, ADM and other network elements.

3. The bidirectional relationship between TM-TM or TM-ADM or ADM-ADM is defined as unidirectional * system. One direction is 0.5 directions * system.