[OptiX OSN 1500B] Phone interface EOW board issue Highlighted

Hi guys!!

I would like to share with you a "query solved" about phone communication service through EOW board.

Description:

There is a problem with a EOW board that it’s installed in a SDH OSN 1500B node.

This board has one RJ-11 port for PHONE channel:

When we make a call between two equipment (Node A – Node B ) through the port EOW (phone-to-phone), when switching the CXLLN board from CXLLN (Slot 5) to CXLLN (Slot 4) in one node (for example in NODE A) , the communication lost (not voice).

The question is:

Is this function/operation correct? Why does this happen?

Solution / Conclusion:

The following figure shows the functional block diagram of the R1CXLLN/R2CXLLN:

As can be seen, the internal call module is implemented within the SCC sub-board of the CXLLN board, and the EOW board that encapsulates the call within the E1 byte is used as an interface only.

Huawei Support confirms that it is normal behavior for the call through the EOW interface to be disconnect when the SCC sub-board of the CXLLN board is resetting or switch.

Exactly the Huawei Support comments "it is just service telephone which transfer by E1 byte. Not need protected service. For currently, we can confirm it is a restriction when SCC board resetting or switch, you must hang up the phone, and dial again".

BR