Switch Administration

PVCConnections

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 ZX-250 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.

s• 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 #

¢• 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 ZX-250 User Guide 4-15

Page 61
Image 61
Cabletron Systems ZX-250 manual VCC Mask Index VPI Bits VPI Values VCI Bits VCI Values