In a site, 1 MCU+16 terminals, we use STM-1 optical interface unit to transmit E1 signal. There is only one main board providing 63 E1 interfaces. We find that some conferences corresponded to E1 interfaces can’t connect.
We focus on the match of MCU and optical transceiver after we make sure there is no fault in transmission link.
Because the customer’s optical transceiver is a product of other company, when the technician assigns the MCU’s E1 interface in network management, the order is not from little to large. So the useful E1 interfaces list between 0 to 62 irregularly. After careful analysis, the interface number of the terminal which can’t connect is larger than 30.
After studying about optical interface unit technique, if we want the E1 interface which is larger than 30 works normally, we must use TMC in main control board.
The problem disappears after using TMC board.
The introduction of optical interface technique in vp8000 introductions is very less. Generally speaking, when we use two optical interface units to work in active or standby mode, the TMC board is useful. This idea leads we don’t use TMC board, so the problem happens.