Nortel Networks 400 4.0, BCM200 manual Selecting trunk MBMs, To select trunk MBMs

106Chapter 8 Installing a media bay module (MBM)

Figure 63 Process for determining MBMs

Determine trunk and extension requirements

Determine DS30 requirements for each MBM

Determine if any offsets can be used

Determine which DS30 buses are available

Set DIP switches on MBMs

Install MBMs into the main unit or expansion unit

The first step in selecting the MBMs is to establish the number of extensions (internal lines) and PSTN lines (trunk lines) you have or need. This step allows you to determine the number and type of MBMs you require. The following sections describe how to determine which MBMs, and how many, you require for your system.

•“Selecting trunk MBMs” on page 106

•“Selecting station MBMs” on page 108

•“Selecting a fiber expansion module (FEM)” on page 109

After you determine the MBMs required, calculate how the MBMs use the available system resources. The following sections describe how the MBMs work within the available channels on the media services card (MSC) in the BCM system.

Selecting trunk MBMs

The number and type of lines coming into your system determine which trunk MBMs, and how many MBMs, you require to support your needs. Trunk lines come from the public network (PSTN) or they support connections in a private network.

If you are setting up an entirely new system, perform a site survey to determine your current and future needs. Nortel recommends that you perform the survey before you order any MBMs.

Note: If you plan to add any lines in the near future, include them in your initial estimates.

To select trunk MBMs

1In Table 25, record the number of each type of line you have. If you do not know the number or type of lines you have, contact your service provider.

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