Nortel Networks BCM1000 - Manual (Page 34)

34 BCM1000, BCM 3.0 addendum
Installation and Maintenance Guide P0607659 02
Full double density means that instead of a DSM16 module occupying a full DS30 bus, the DSM16+ can be set
to double density, so that it occupies only half the bus, allowing you to install a second DSM16+ set to double
density with offset 1. This doubles the available telephone lines from 16 to 32. Similarly, where the DSM 32
required two DS30s, if the DSM32+ is set to double density, the module only requires one DS30 bus to support
all 32 lines. The ASM8 requires no special settings to take advantage of double density. You can simply install
four modules on one DS30 bus, with the dip switches set to the four offsets. The exception is for DS30 06 and 07
if they are set to PDD. In that instance, you can still only install two ASM8s per bus.
Figure 12 shows how much of a DS30 bus each station module requires.
Figure 12 Space requirements for station media bay modules, on a per-DS30 configuration
The following diagram provides a system view of what double density looks like from a system perspective. Note
that this example is based on the default setting, which provides partial double density to DS30 06 and 07.
Single-density mode
Double-density mode
4 DD ASM8s
1 DS30 bus/
per DS30
2 DD
per DS30
1 DS30 bus
1 DD
per DS30
1 DS30 bus
1 DSM 16
per DS30
1 DS30 bus/
offset set to 0
1 DSM 32
per 2 DS30s
2 DS30 buses/
offset set to 0
PDD note: If DS30 6 and 7 are in
partial double density mode, you can
only install modules set to single
density. This also means that only two
ASM8s could be installed on each
DS30 bus.
DSM 16+
DSM 32+