This MIB module is intended for the management of network clock 
distribution and the Network Clock Distribution Protocol (NCDP) 
in Cisco MGX ATM switches. This MIB allows enabling automatic network 
clock configuration and distribution as well as configuration of 
manual clock sources.  

NCDP allows automatic distribution of network clocking sources
in the network. A spanning network clock distribution tree is
constructed by each node in the network and each node is 
synchonized to one single 'master' clock reference. 

A source of network clock for the device may be an oscillator
local to the device or a Building Integrated Timing Supply (BITS)
port or an interface that supports synchronous clock recovery.

An 'index'('cwnClockSourceIndex') is assigned by the NCDP
protocol entity in the managed system to identify each available 
source of network clock on the managed system.