60 Chapter 4 Selecting the media bay modules for your systemN0008587 01Selecting the trunk media bay modulesThe number and type of lines coming into your system determine which trunk media bay modules,and how many modules, you require to support your needs. Trunk lines come from either thepublic network (PSTN), or they support connections in a private network.If you are setting up an entirely new system, a site survey must be done to determine your currentand future needs. We recommend that you do the survey before you order any modules.To select the trunk media bay modules:1 Record the number of each type of line you have in Table 8.If you do not know the number or type of lines you have, contact your service provider.2 Use the number of lines and the number of lines per module to determine how many modulesyou need.Note: If you plan to add any lines in the near future, include them in your initial estimates.Table 8 Determining trunk module requirementsType of lines Number of linesType of media baymoduleNumber of linesper moduleNumber of modulesrequiredT1 digital lines DTM 24 ______ DTMPRI digital lines (NA) DTM 23 ______ DTME1 digital lines DTM 30 ______ DTMPRI digital lines (EMEA) DTM 30 ______ DTMAnalog lines CTM(North Americansystems only)4 ______ CTMAnalog lines GATM4 4 ______ GATM4Analog lines CTM8(North Americansystems only)8 ______ CTM8Analog lines GATM8 8 ______ GATM8Analog lines 4X16 combinationmodule(North Americansystem only)4(also requires afull DS30 bus forthe DNs)______ CTM4BRI ISDN lines BRI 4 ISDN loops (8lines)______ BRI
