Nortel BCM200 Installation And Maintenance Manual page 52

52 Chapter 2 Introducing the BCM hardware
If your system requires many IP lines or trunks, you can reduce the number of DS30 buses that are
assigned to MBMs and increase the number of buses available to IP telephones. This is known as a
3/5 DS30 bus split. In this case, you only have five DS30 buses available for use by the MBMs.
Refer to "Understanding DS30 numbers" on page 109
Warning: Changing the DS30 bus split
If you change the bus split from 2/6 (default) to 3/5 after the system is initialized, any
module set to DS30 bus 7 or requiring the use of bus 7 becomes inoperable.
If you change the bus split from a 3/5 split to a 2/6 split after the system is initialized, all
data is lost and all optional applications must be reinstalled and reconfigured.
Figure 25 Telephony hardware components
Refer to "Media bay module availability" on page 355
and "FEM MBM–Norstar trunk cartridge
combinations" on page 356
and which types of trunk lines are available in your
location.
The MBMs connect with external devices to implement various types of voice trunks and
extensions. Install the MBMs in the MBM bays in the BCM200 or BCM400 main units and the
BCM expansion unit.
MBMs have LEDs on the faceplate. For information on MBM LEDs, see
system LEDs" on page
The back of the MBM has a single connector that provides signaling channels, media channels,
and power to the MBM. This connector plugs into the MBM backplane in the main unit or
expansion unit. Some MBMs also have a cooling fan that runs off the MBM power source.
26 shows the rear views of the two types of MBMs.
N0060612 N0060612
to determine which MBMs
77.
Note: Refer to "Media bay module availability" on page 355
MBMs and which types of trunk lines are available in your location.
for more information.
CTM 4
1 Aux 2 3 4
DSM 16+
1 2 3 4 1 2 3 4
Power Status
"Telephones and adapters"
on page 73
"Trunk media bay modules
(MBMs)" on page 53
"Station media bay modules
(MBMs)" on page 57
"Specialized media bay
modules (MBMs)" on page
"Viewing the BCM
to determine which
Figure