Hello friends. Let's talk about the J0 byte. The byte J0 in STM frame is used for path tracing / section tracing. In simpler terms, this byte will contain a 8-bit word with which the receiver checks the connectivity with the transmitting node. The same word will be sent continuously for transmitting one particular information using more than a frame. The trace byte is used by the receive end to confirm if it has a continuous connection with the transmit end. The trace byte can be set to any identical character for equipment of the same vendor but if the equipment is from different vendors, the trace byte must be set to the characters previously specified to ensure successful interconnection.
The traditional application of the J0 byte is for the interconnection of networks of different providers. But the proposals that I bring you allow to identify connectivity problems in complex networks with multiple fiber optic links with links supported in common fiber optic cables and allows us to quickly identify an intervention error in the event of fiber optic failures, it also allows to avoid layer network ties 2 in EoSDH services in the event of intervention errors. You can check the post on loops problems. Talking about loops in SDH and EoSDH
The proposal is to use NE ID-Slot ID- Port ID as the word to be sent by the byte J0 NE. If there is an error in the interconnection of optical fibers, the alarm HP_TIM quickly appears. The HP_TIM is a trace identifier mismatch alarm in the higher order path. We quickly identify an intervention error with the byte that identifies the path.
