User Manual

ADCP-75-192 • Issue D • October 2005 • Section 1: Overview
Page 1-12
 2005, ADC Telecommunications, Inc.
3.7.12 Ethernet Hub
Each Hub rack is equipped with a 24 port Ethernet Hub, at the top of the rack, below the HRM.
It is powered by 120 VAC. An optional –48 VDC can be chosen. The Ethernet Hub is used to
connect RAN CPU’s (through Hub SIF’s) and Hub CPU’s to and existing LAN/WAN and to
each other.
3.8 Communication Interfaces
3.8.1 I2C
I2C is a bi-directional serial bus that provides a simple, efficient method of data exchange
between devices. It is used for the board level communications protocol.
I2C interfaces are used for communication to the following modules:
1. HUB - HDC, FSC, HUC, BIM, PSI
2. RAN - RDC, RUC, PIC, P/MCPLR, C/MCPLR
3.8.2 Network Interface
The Hub Master CPU’s are able to communicate to any other CPU in the Digivance CXD
system (Hub and RAN) over an Ethernet LAN using the IP based Simple Network
Management Protocol (SNMP). Ethernet connections are aggregated with each rack via an
Ethernet Hub. Inter-rack communication is done by connecting the Ethernet Hubs between
racks.
Each SIF has a 10BaseT Ethernet connection. The Hub Master CPUs are able to communicate
with the RAN’s over this Ethernet connection.
3.8.3 SNMP
The ADC Digivance Simple Network Management Protocol (SNMP) Agent and the ADC
Management Information Bases (MIBs) provide the interface into the Digivance CXD system.
A MIB is a database where scalar or tabular data “objects” known to both agent and the
manager are defined and stored. The MIBs define a set of parameters with specific
characteristics, including name, data type, value range, description, and read-write
accessibility. An SNMP manager sends SNMP SET and GET messages to the various nodes in
the Digivance CXD network in order to access MIB’s.
The MIBs are compiled into a SNMP Manager as well as the Digivance CXD SNMP Agent so
that both manager and agent software can communicate. Agent and manager each have their
own copy of the MIB. Using the SNMP interface, the manager issues GET and SET
commands for object attributes stored in the agent MIB. In addition, the manager receives
unsolicited object attributes in the form of TRAP notices sent by the agent. The Digivance
software has the ability to send SNMP TRAPS when certain MIB conditions are detected.
reducing the amount of polling via SNMP GET requests from the SNMP manager.