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Cisco MGX 8220 Installation and Configuration
Release 5.0, Part Number 78-6430-03 Rev. D0, November 2003
Chapter Core Module Overview
In this format, the virtual circuit is defined by

Slot specific position of the VPI

4-bit slot number position of the VPI

10-bit logical channel number ( L C N) a ssigned as the VCI

The CC/FFCI/Supervisory field is used for ForeSight bits and a Supervisory bit.

Figure2-14 Cisco MGX 8220 ATM Trunk Cell Format

Figure2-15 CC, FFCI, EFCI, Supv, PTI, and CLP Fields

1000
Slot#
LCN<7:0>
CC/FFCI/Supv
see below PTI/EFCI/CLP
see below
HEC
Payload
53
6
5
4
3
2
1Local VPI
10
VPI
VCI
HEC
53
6
5
4
3
2
1VPI
Payload
LCN<11:8>
VCI
CC/FFCI/Supv
see below PTI/EFCI/CLP
see below
H8254
FFCI Supv
msb
CLP
PTI
EFCI bit if msb is set
CC
H8255