COMSPHERE 3600 Series Data Service Units5-12 July 1999 3610-A2-GB41-70Backup BranchThe Backup (Bckup) branch controls operation of thepoint-to-point dial backup feature. The Bckup selectiononly appears when a DBM (V.32 DBM, 4-wireSwitched 56 DBM, or 2-wire Switched 56 DBM) isinstalled, Central-Site Bridge (CBrdg) is enabled, orAggregate Switch (AggrSwitch) is enabled.The DBM/DBM-V/DBM-S/DBM-D section discussesthe full set of available commands when a DBM isinstalled. Multipoint dial backup requires a TDM orMCMP to be installed, with the DSU-TDM orDSU-MCMP configured as a central-site bridge(MUX Funct: CBrdg), with an associated DBM-V,DBM-S, or DBM-D for each remote drop (refer to theBridge section).For additional DBM operation information, refer to theCOMSPHERE 3600 Series Data Service Units, Models3610 and 3611, Dial Backup Module and SNA DiagnosticInterface Options, Applications Guide.DBM/DBM-V/DBM-S/DBM-DThis section discusses the full set of commandsavailable in the Backup branch when a DBM is installed.NOTEReferences to DBM in this guidealso apply to a DBM-V, DBM-S,or DBM-D.The Backup branch menu items displayed depend onthe DBM’s current operating mode:• Idle mode – The DBM has no call in progress, butmay be either enabled or disabled. If the DBM isenabled, the DDS circuit is carrying data anddiagnostics. If the DBM is disabled, no calls can beinitiated or answered.• Standby mode – The DBM has a dialed orswitched 56 kbps connection to another DBM orcompatible modem, but the DDS circuit is stillactive and carrying data. The dialed or Switched56 kbps digital circuit carries diagnostic trafficaddressed to either the tributary DSU or DBM.These diagnostics do not disrupt the DDS circuit.• Dial Backup mode – A dialed connection isestablished and is the active link, carrying data anddiagnostics.Table 5-5 lists the current DBM modes, the availableselections, and the mode in which the selection places theDBM.
