380 Appendix B: ISDN OverviewEnterprise Edge 2.0 Programming Operations Guide P0911588 Issue 01If your system has both an EE-BRIM S/T configured as BRI, and an EE-DTMconfigured as PRI, it is recommended that you use PRI as the primary clock source.See PRI hardware on page 377.Other ISDN BRI equipmentNT1The NT1 (network termination type 1) connects an S interface (four-wire) to a Uinterface (two-wire). In most cases, it connects loops from an EE-BRIM S/Tmodule to the network connection, which uses the Uinterface .The NT1 converts and reformats data so it can be transmitted to and from the S orT connection. In addition, it manages the maintenance messages travelling betweenthe network and the NT1, and between the NT1 and the Enterprise Edge system.The NT1 from Nortel Networks is packaged two ways:• a stand alone package which contains one NT1 card (NTBX80XX) and a powersupply (NTBX81XX)• a modular package which contains up to 12 NT1 cards (NTBX83XX) and apower supply (NTBX86AA)ISDN standards compatibilityIn North America, Enterprise Edge ISDN equipment supports National ISDNstandards for basic call and calling line identification services. Enterprise Edge BRIis compliant with National ISDN-1 and PRI is compliant with National ISDN-2.Enterprise Edge does not support EKTS (Electronic Key Telephone System) orCACH (Call Appearance Call Handling).In Europe, Enterprise Edge supports ETSI Euro and QSIG standards, andPRI SL-1 protocol.Planning your ISDN networkConsult the Enterprise Edge Installation and Maintenance Guide to determine aconfiguration of ISDN trunks and terminal equipment (TE) for the Enterprise Edgesystem, then order the appropriate ISDN capability package from your ISDNservice provider.For ISDN BRI service your service provider supplies service profile identifiers(SPIDs), network directory numbers (Network DNs), terminal endpoint identifiers(TEIs), and other information as required to program your Enterprise Edge, TE andother ISDN equipment.
