Adtran MX2800 M13 User Manual

MX2800 M13 Multiplexer User Manual

Configuration, Section 3

61200290L1-1G

    3-5

First and second generation DS3 controller cards (P/N 1200288Lx and P/
N 1202288Lx) use Long for distances over 50 feet and Short for distances
under 50 feet.

Fifth generation DS3 controller cards (P/N 1205288Lx) do not require a
DS3 line length setting; therefore, Line Length does not appear as a menu
item.

When the MX2800 is connected to a network that provides timing, configure the MX2800 for LOOP

 

timing to derive timing from the network. If the MX2800 is the master timing source for the circuit, 
configure the MX2800 to LOCAL. In applications where two MX2800s are connected back-to-back with 
an un-channelized DS3, configure one MX2800 to LOOP and one MX2800 to LOCAL

.

 

The following four options are available for remote loopbacks:

• FEAC/C-BIT

 is used t

o allow the MX2800 to respond to remote loopback requests received over either 

the DS3 Far End Alarm and Control (FEAC) channel and/or DS2-level C bits. This mode is valid in 
both 

C-BIT

 and 

M13 

framing formats. 

• FEAC is used to allow the MX2800 to respond only to remote loopback requests received over the DS3 

FEAC channel. This mode is valid only when using C-BIT framing. In this mode, DS2 C-bit loopbacks 
will be ignored. 

• C-BIT is used to allow the MX2800 to respond only to remote loopback requests received over DS2 C 

bits. This mode is available when operating in either C-BIT or M13 framing. In this mode, FEAC 
loopbacks received when operating in C-BIT framing will be ignored. 

• Disabled is used to ignore all out-of-band loopback requests (FEAC and DS2 C-BIT). When 

Disabled

 

is selected, the MX2800 will still respond to individual T1 in-band CSU/NIU loopbacks if so configured 
in the T1/E1 Loopback Detection menu.

Choose FEAC/C-BIT via menus in either C-BIT or M13 framing modes;
however, there is no FEAC channel when framing is set to M13.
Therefore, no DS3 far end alarms or loopback requests via the FEAC will
be valid when the MX2800 is configured for M13.