Cisco Systems MGX 8220 VC Connections, VP Connections

6-4
Cisco MGX 8220 Installation and Configuration
Release 5.0, Part Number 78-6430-03 Rev. D0, November 2003
Chapter
VPI/VCI Mapping
VC Connections
For FRASM and AUSM VC connection s, the user associates a logical channel number (LCN) with t he
connection DLCI for a service mo du le in a particular slot. The card’s slot numb er i s u sed as the value
for the VPI and the LCN is use d as t he value for the VCI.
The VPI, therefore, is a number in the range of 5 to 14 (the range of permissible slots for service
modules in the MGX 82 2 0) .
The VCI range is determined by the service module type and is 16 to 271 for 4-port FRAM and AUSM
modules and 16 to 1015 for 8-port modules.
VP Connections
For AUSM VP connections, the situation is m ore complicated. The CPE port VPI value will most likely
be different from the network VPI. D epen ding up on t he BNM in terf a ce for mat (UNI or N NI), th e rang e
of VPI values is evenly divided among the 10 service module slots. During the process of adding a VP
connection, the user is asked to assign a VP ID where the VPI D i s an in d ex c orresponding to the VPI
within the assigned range.
The ranges of VPID for the various service modules are shown in Table 6-1.
There are two methods that can b e used to identify the network V P I ass o ci at ed w ith a n AUSM V P
connection.
The first method is to enter the dspadrxlat command. This command lists all t h e V C an d V P
connections currently existing on the shelf in slot number/channel number order showing the
connection type and the VPI valu e f o r eac h c on n ect io n .
For example, the command
myshelf.1.4.ASC. a > dspadrxlat
could result in the following response
The second method is to calcul at e th e VPI from the slot number and th e V P ID val ue .
For UNI interface format:
VPI = (slot number - 5 ) * 20 + (VPID - 1) + 1 6
For NNI interface format:
VPI = (slot number - 5 ) * 340 + (VPID - 1) + 16
Table6-1 VPID Ranges
Interface Type VPID
AUSM-4T1E1 AUSM-8E1T1
UNI 1–20 1–20
NNI 1–255 1–340
Chan Connection Type VPI
1.8.16 vpConnection 76