Hardware / 461P0992638 03 Modular ICS 6.0 Installer GuideI/F levels Installer password requiredInterface levels defaults to the ISDN loss plan setting.Press CHANGE to select setting: ISDN, PSTN or ISD/TT interfacelevels.Tips - Find out if your Norstar system is connected to acentral office (CO) with digital network loss treatment(ISDN I/F levels) or analog network loss treatment(PSTN I/F levels) by checking with your telecommunicationsservice provider.The ISDN setting requires digital access lines (DAL) that havedigital network loss treatment. On a DAL network, it is thePBX that administers the dB loss. DALs may have ISDNsignaling or digital (such as T1 and so on) signaling. To haveDAL network loss treatment on a line with digital signaling,you must contact your service provider.The PSTN setting requires analog access lines (AAL) thathave analog network loss treatment and digital signaling. Onan AAL network, the CO administers the dB loss.Tips - The ISD/TT setting is only for T1 and PRIinterfaces (MCI services only). ISD/TT provides a loss levelthat is similar to DAL except for certain analog connectionswhere the DB level increases by three.Each loss plan uses a transmit objective loudness rating of -46 dB. The ISDN and ISD/TT loss plan uses a receiveobjective loudness rating (ROLR) of 51dB and the PSTN lossplan uses a ROLR of 48 dB.Choosing the wrong setting may affect voice quality.
