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re:B3 question




Hi Ben,

The B3 octet covers the previous SPE.  Also note that the SPE
includes the path overhead, the fixed stuff, and the payload.
The SPE from the transmitter is fixed to start after the
last Z0 octet in the 1st row, 577th column, of the next SONET frame.

So for the transmit case, the B3 octet located in the 2nd row,
577th column of WIS frame #N+1 covers the SPE which is entirely
in the envelope capacity (all octets in columns 577 to 17280,
rows 1 to 9) of WIS frame #N.

Cheers,
Erik

In message "B3 question", bebrown@xxxxxxxxxxxxxxx writes:
>Hi,
>
>B3 is in the path overhead column of the 2nd row in the WIS frame.
>It is specified to cover the most recent SPE. However, the SPE from
>the transmitter starts after the "fixed stuff" in the 4th row and
>runs to the end of the next 3rd row.
>
>Does this mean that the B3 octet in WIS frame #N covers the SPE
>that starts in WIS frame N-2 and ends in WIS frame N-1?
>
>Thanks,
>Ben
>
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>Benjamin Brown
>Router Products Division
>Nortel Networks
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