Wednesday, 20 March 2013

Detailed study of multiplexing process in SDH - Interview notes - Part II

      Further to previous post, let us read about mapping VC-12 into TU-12, TU-12 to TUG-2, TUG-2 to TUG-3 & TUG-3 to VC4.

Mapping of a VC-12 into a TU-12 signal.

  In order to detect the start of the 2 Mbit/s signal and thereby the start of the customers data, The V5 byte must be seen be the distant end. This is achieved by adding four overhead bytes to the multiframe, which together form a calculated byte count to the start of V5. This is called a pointer value and is known as the TU Pointer.

There are four pointer bytes called V1, V2, V3 and V4, which are used to calculate the location of V5.

Multiplexing of TU-12 into a TUG-2:

If you have any questions, you can add them in comments section. I will provide you the answer.

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