Brief about GCC (General Communication Channel ) bytes in OTN network?
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.
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
Example :-
Huawei DWDM/OTN <---------------> Multiples Ciena 6500 OTN/DWDM <--------------------> Huawei OTN/DWDM
Is there is any way we can test GCC0 bytes configured transparent in in 3rd party network involved multiple OTN equipment’s ? Can we perform using OTN Analyzer or any other method?
Answer: -
- Connect the OTU2 circuit configured via Multi-vendor OTN/DWDM equipment to the OTN Analyzer
- Change GCC overheads to different values other than default values
- Check in OTN analyzer if the overheard bytes are coming or not
In Monitoring systems of different vendors, the only indication for the operator that the GCC0 / GCC1 is not being received from the far end is when the GCC link fail alarm is reported
Please note that GCC0 is terminated and GCC1 is carried across the ODU (terminal to terminal).
