RELEASED
PM73123 AAL1GATOR-8
DATASHEET
PMC-2000097
ISSUE 2
8 LINK CES/DBCES AAL1 SAR
credits per cell is 46-7/8. For unstructured lines, the average number of
credits per cell is 47.)
Credits = 59.375 – 46.875
Credits = 12.5
5) The frame differential for the next service is computed from the number of
credits needed to exceed 47 and NUM_CHAN, the number of channels
allocated per frame.
47 – 12.5 = 34.5
34.5 / 4 = 8.625
Round 8.625 up, so the frame differential is 9.
6) Therefore, the next cell will be sent nine frames ahead of the current cell.
Next frame = present frame number + 9
7) The CSD circuit computes the number of credits for those nine frames and
adds the result to the total.
New credits = 9 x 4 = 36
QUE_CREDITS = 36 + 12.5 = 48.5
If the queue is on a line in SDF-MF mode, the CSD makes a signaling
adjustment to the QUE_CREDITS before writing this value to memory. (If the
queue is not in SDF-MF mode, the signaling adjustment is not made and the
QUE_CREDITS calculated in Step 7 is written to memory.)
The calculation determines the number of signaling bytes in the structure,
then generates an average number of signaling bytes inserted into cells per
frame, and finally multiplies this average number by the frame differential to
adjust the QUE_CREDITS.
8) The CSD converts the frame differential from units of frames to units of
one-eighth of multiframes.
In performing this calculation, the CSD also uses the FRAME_REMAINDER
value from the QUE_CREDITS location in the T_QUEUE_TBL. This example
assumes that FRAME_REMAINDER = 1 from the previous calculation on this
queue.
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