GCC (General Communication Channel ) bytes in OTN

General Communication Channel (GCC) bytes for overhead communication between network nodes.

•  The GCC is used for OAM functions such as performance monitoring, fault detection, and signaling and maintenance commands in support of protection switching, fault sectionalization, service-level reporting, and control plane communications
• GCC0 – two bytes within OTUk overhead. GCC0 is terminated at every 3R (re-shaping, re-timing, re-amplification) point and used to carry GMPLS signaling protocol and/or management information.
• GCC1/2 – four bytes (each of two bytes) within ODUk overhead. These bytes are used for client end-to-end information and shouldn't be touched by the OTN equipment.
• SONET/SDH where the data communication channel (DCC) has a constant data rate, GCC data rate depends on the OTN line rate. For example, GCC0 data rate in the case of OTU1 is ~333kbit/s, and for OTU2 its data rate is ~1.3 Mbit/s.

Practical scenario of monitoring GCC bytes :   

Service is created as OTU2 in Core network & metro network. 

GCC0 – two bytes within OTUk overhead for management information with respect remote management of NE ( Here it is Metro/Longhaul Network Equipment management)

Would like to get access of metro network by GGC0 byte enabling in metro & GCC0 transparent mode in core network.

Scenario is as below:-

Metro/Longhaul Network Equipment <---------------> Multiple Core Network Equipment’s ( 3rd Party Provider network) <---------------------> Metro/Longhaul Network Equipment