VC-3 Level Cross Connection does not provide VC-12 Level output, why?

Recently, I have found that, when VC-3 Level cross connection is done VC-12 output at drop end cannot work. I can tell it with detail scenario:

Lets say,  we have 3 station A, B, C.  At A &C Station, cross-connection level is VC-12 and A & C also carries the terminal point of the service which means E1 level service dropped at A & C (through PQ1 card).  But at Station B, cross-connection level is done at VC-3 level. Due to this scenario, service does not get active/up. When the CC level changed to VC-12 at Station-B, the service gets up. Before the CC level changed, we have done all sorts of physical and logical test such as loop, PRBS etc but did not work out. That is why, we had to change the CC level of station B.

Now, Can anybody say, from the point of view of SDH frame structure, why VC-3 cannot provide VC-12 level output. Even VC-4 can provide VC-12 output. As per order, VC-3 & VC-4 both are higher order, but why VC-3 does not provide VC-12. I have searched SDH frame structure documents but could not differentiate why it does not work out from the available logic.

Appreciate, if anybody can share the logical reason based on frame structure.

Thanks

Raihan

Dear raihan,

So sorry about the delay of the reply.

We are finding an expert to reply you, pls waiting for a little longer.

Thank you so much.

Hello Raihan,

Thank you for your question, we just support the following SDH mapping and multiplexing structure for SDH services :

 

    
     Dear raihan,

Thank you for your question, you can use this document  ( SDH and signal level in PDH and SDH)













    
   
    
    
    
    







Dear z00254961 & NIKMARAMH,

Thanks for your valuable feedback. I will study the document. I will read the document and will come back if future question arises regarding this.

Thanks

Dear raihan118,
You are welcome. :)

Hello Raihan,

Its my pleasure. If you have any other question, please feel free to contanct me, thank you.