61202.086L1-1 ISU 512 User Manual 9Chapter 3InstallationINSTALLATIONAfter unpacking the unit, immediately inspect it for possible shipping dam-age. If damage is discovered, file a claim immediately with the shipping car-rier, then contact ADTRAN Customer Service; see the inside back cover of thismanual for phone numbers.NETWORK CONNECTIONThe ISU 512 (U interface) supports either Dial or Leased operation. The ISU512 (ST interface) supports only Dial operation. Four 8-pin RJ-45 modularjacks on the rear panel of the ISU 512 allow connection to either network ser-vice.Dial operation uses the ISDN Basic Rate interface and allows the ISU 512 todial out over the ISDN network. When used in this mode of operation, thetelephone company provided ISDN Basic Rate interface is connected to the RJ-45 connectors marked ISDN IFC #1, #2, #3, and #4. Connect the Basic Rate in-terfaces to the ISU 512 in order, starting with ISDN IFC #1, until the maximumnumber of lines (four) is reached.The Leased mode of operation supports a dedicated 2B1Q data service at ratesof up to 512 kbps by using nailed up circuits or a permanent connection be-tween end points. This could be a limited distance modem or point-to-pointconnection.See the appendix Pinouts for network connection pin assignments.
