sundance-communications.com/forum Forums TDM Business Telephone Systems Nortel Telephones & Systems BCM 400

I am setting up a BCM 400(first time). I have a couple of questions, hope someone can help!
The following is the hardware.
BCM 400 3.7, 1 Expansion unit
1 DTM Module(for a 23 channel PRI),2 DSM-32+ Modules,1DSM-16+ Module
2 Global ASM8 Modules(GASM8)
Questions:
1. How do I know when to use single or double density?
2. Does the main cabinet and the expansion both have 8 buses each available (or am I way off base here)
3.What MBM's should I put in the Main Cabinet and what MBM's should I put in the Expansion Cabinet or does it matter.
4. And I am not sure about the Offsets.
If anyone can help that would be awesome. Thanks in advance!!

I will do the best I can and I know that anything I say will be corrected if wrong. So that is great.
You have bus 2 - 7 for the whole system not for each. You want to have your stations starting in the lowest bus going high and your trunks start in the high going lo. You want DTM's out at 7 then any POTS modules to follow lower. You want to have your DSM's in 2 up followed by Analogs. I would put the 32+ at 2&3 and your 16+ at 4. YES - Use double density or you will be wasting bus numbers. I would put the DTM in the main cabinet. The rest can go anywhere, but I would still put the DSM's in the main first.
DTM - Bus 7 - 4 & 6 off
DSM-32 - Bus 2 - 1 off
DSM-32 - Bus 3 - 1 & 6 off
DSM-16 - Bus 4 - 1 & 5 off
GASM8 - Bus 5 - 5 & 6 off

You must use single density if the software is 2.5 or older.

I hope this is correct and it helps.

Thank you it does. I have been charting everything while awaiting response and I have everything pretty much as you got it. The difference being I put the 16+ in bus 2 and the 2 -32+ modules I put in three and four. Should this matter?

It will work either way. It is just my preference to put the 32's first. Just have to keep track of the ports and DN numbering, either way you do it. And as far as which cabinet, I always think if the main unit goes down, it is ALL down. If just the expansion goes down, what is most important to keep running. But it is still best (maybe necessary) to put the DTM in the main, though.

Thank you for all you help!!

Great explanation NT.

Another question guys. I have been reading the manual as I go here. Came across another d-density chart that differs to the first one I have been following. It gives me the option of an A or B setting for the Dip Swithches on the DSM Modules. I would like to have all the extensions from 221 on in numerical order. Am I reading this wrong or is this not possible.

GASM8:
as above I came across another chart which differs from the main chart I have been using.
I have 2 GASM8 modules and it says that I can place two GASM8 modules on the same bus (DDensity) The dip switch settings differ from the ones NTlayoff gave me. Any feed back would be great Thanks :confused:

On bus off bus, sounds like scsi!!

I missed the first time around that you had TWO GASM8 modules. Yes, you can put two on the same bus. Just have to offset the second one with the dip switch. You would have dips like this:

DTM - Bus 7 - 4 & 6 off
DSM-32 - Bus 2 - 1 off
DSM-32 - Bus 3 - 1 & 6 off
DSM-16 - Bus 4 - 1 & 5 off
GASM8 - Bus 5 - 5 & 6 off
GASM8 - Bus 5 - 3,5,6 off

For the DSM when it says A & B, it is talking about the amphenol connections on the module. The top connection has 16 stations called A connection and is really the 2nd half of the stations and the bottom connection has 16 stations called B connection which is really the first half of the stations. DUH. Why they didn't put the first half on top called A is beyond me.