Beta Draft Confidential
Configuring ATM PVCs
Setting the VPI/VCI Values for PVCs
ATM Services Configuration Guide for CBX 3500, CBX 500, GX 550, and B-STDX 9000
1/19/05
10-9
Setting the VPI/VCI Values for PVCs
For each PVC you configure, you must specify a value from zero (0)-nnnn to represent
the VPI for the PVC (see
). The maximum value that you can specify is
based on the Valid Bits in VPI that is configured for the logical port, as follows:
Maximum value = 2
P
– 1
where P is the value in the Valid Bits in VPI field. For example, if you entered 5 in the
Valid Bits in VPI field, the maximum value is 31 (2
5
– 1 = 31), which would give you
up to 32 virtual paths (numbered 0-31). See
for details on setting the
number of Valid Bits in VPI.
If you are defining a VCC, you must also specify a value to represent the VCI for an
ATM circuit (see
). The maximum value that you can specify is based on
the Valid Bits in VCI value that is configured for the logical port, as follows:
Maximum value = 2
C
– 1
where C is the value in the Valid Bits in VCI field. For example, if you entered 6 in the
Valid Bits in VCI field, the maximum VCI value you can enter is 63 (which would
give you 32 virtual channels, numbered 32 to 63).
The VPI/VCI combination must be unique at each circuit endpoint (including
multipoint circuits). As a result, since a VPC has access to all valid VCIs, a VCC or
multipoint circuit that uses a VPI that is already assigned to a VPC cannot be
established, nor can a VPC be established if the selected VPI is already assigned to a
VCC or multipoint circuit.
Configuring an ATM Service PVC
To configure attributes for this type of PVC, define the following parameters for each
of the circuit’s two endpoints. If you are configuring a circuit with an ATM circuit
emulation (CE) endpoint(s), the VPI value defaults to zero (0) and the VCI value
defaults to 256.
VPI (0..nnn) — Enter a value from 0-nnnn to represent the VPI for the PVC. The
maximum value you can enter is based on the valid bits in VPI that are configured for
the logical port. Note that zero (0) is not a valid value for a management PVC. See
“Setting the VPI/VCI Values for PVCs”
for information about setting this value.
Note – These VPI/VCI range restrictions only apply to VCCs. You can provision a
VPC to any value in the VPI = 0 - 255 range. In addition, if the logical port uses the
NNI cell header format, you can provision VPCs over the 0 - 4095 range. For more
information on the Valid Bits in VPI/VCI fields, see
Содержание CBX 3500
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