Cabletron Systems 6A000 VCC Mask Index VPI Bits VPI Values VCI Bits VCI Values, ZX # set vccmask

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Table 4-1 Values for VPI and VCI

VCC Mask Index	VPI Bits	VPI Values	VCI Bits	VCI Values
0	0	0	12	0 to 4096
1	2	0 to 3	10	0 to 1023
2	4	0 to 15	8	0 to 255
3	6	0 to 63	6	0 to 63

Use the show vccmask command to view the four preconfigured VPI/VCI combinations.

SmartCell ZX # show vccmask

MaskIndex	VpiShift	VciShift
	(In bits)	(In bits)

============================================================================

0	0	12
1	2	10
2	4	8
3	6	6

SmartCell ZX #

VCCMask combinations dictate what numerical values can be used for VPI/VCI pairs. Any VPI and VCI pairs that fit the bit distribution of one of the indexed combinations can be used for defining a PVC. If the VPI and VCI values do not fit one of the indexed combinations, the SmartCell 6A000 uses the closest matching indexed combination.

If you need to use values for VPI and VCI that do not fall within the range of one of the preconfigured indexed combinations, use the set vccmask command to replace one of the preconfigured combinations.

For example, change VCCMask indexed combination zero (0) from VPI = 0 bits and VCI = 12 bits to VPI = 3 bits and VCI = 9 bits.

1.Use set vccmask to change the VPI/VCI values to 3/9.

SmartCell	ZX # set vccmask
MaskIndex(0)		: <we replace the first VPI/VCI pair
VPIShift(0)		:	3
VCIShift(12)		:	9
SmartCell	ZX #

2.Use the show vccmask command to see the new VPI/VCI combination.

SmartCell ZX # show vccmask

MaskIndex VpiShift VciShift

(In bits) (In bits)

============================================================================

0	3	9	<for index 0, VPI/VCI now equals 3/9
1	2	10
2	4	8
3	6	6

SmartCell ZX #

SmartCell 6A000 User Guide 4-15