1. OSC and ESC application scenarios:
1.1 When OSC is necessary?
1) Adopt orderwire phone.
2) OLA (without services added or dropped).
3) Support WDM channel ASON.
4) Provide optical layer management overhead of OTN.
5) Support OWSP protection.
1.2 When ESC is necessary?
1) CWDM network.
2) Beyond 52dB, single long hop.
2. OSC and ESC features:
2.1 OSC (Optical Supervisory Channel) : The OSC transmits the monitoring and management information among the stations. The channel of the OSC is at 1510 nm, that is to say, it is independent main signal and supervisory signal. The OSC boards include the HSC1, SC1 and the SC2, and the insertion loss of FIU must be considered. And any site can be supervised by OSC.
2.2 The ESC(Electrical Supervisory Channel) : it reduces the investment of the OSC. It also deletes the insertion loss of the FIU. This lowers the cost and the power budget of optical channels. But the following restrictions on using ESC is as follow:
No services are added to or dropped from the OLA site. The ESC function cannot be provided by the OTU. Use the DCN network to provide management.
When the ESC is used, order wire cannot be provided. At present, order wire interfaces are on the OSC board.
