Nortel Networks R2MFC Manuale Utente

46 Chapter 5 Configuring the R2MFC MBM

NN40010-300

The MBM has two options for physical connections on the faceplate:

1 RJ-48 connector for twisted pair cable (line impedance of 120 Ohms)

2 a pair of BNC connectors for coax cables (line impedance of 75 Ohms)

The BNC connectors can have one of the following:

•

TX shielding connected to ground (default)

•

RX and TX shielding not connected to ground

Only one of the two connector types can be active. The default active interface is the BNC 
connector. The BCN connector is part of the country-specific defaults for Mexico. Each of the 
country codes activates the appropriate connector, based on the country standard for connectors. 

The active interface can be customized in the firmware through the CLI by using commands in the 
COnfig directory. 

The external link uses Channel Associated Signaling on timeslot 16, therefore; TS16 multiframe 
format is always used. In addition, optional CRC4 multiframe can be used (for monitoring digital 
transmission quality), instead of basic “alternate frame” format.

The CRC4 multiframe option is activated by the firmware as part of the country-specific defaults.

PCM coding is A-law.

These settings can be customized in the firmware through the CLI by using commands in the 
ALarm directory.  

Note: Changes made to the framing parameters must be configured in both the R2MFC 
MBM and the BCM.