Total Access 3000 DSLAM DS3 Primary Switch Module Installation and Maintenance Practice2 61181041L3-5ADescriptionThe DS3-PSM is a common plug-in module used in the High Density Expansion (HDX) archi-tecture. The DS3-PSM is an Asynchronous Transfer Mode (ATM) switch with the switching,policing and shaping functionality of a typical ATM switch, plus the added functionality toextend these functions across five additional expansion shelves. The DS3-PSM is designed tointerface with an Expansion Switch Module (ESM) on expansion shelves via shielded CAT 5ecables to accomplish the expanded switching capabilities. The DS3-PSM functions as a fulllocal ATM cell switch; as a result, it can locally switch any data path as well as pass it back upthe high-speed network connection.The core of the HDX system switching is comprised of the equipment listed in Table 1.The Total Access 3000, when functioning as an HDX platform, must employ a DS3-PSM andan ESM. Refer to the Total Access High Density Expansion (HDX) System Manual (P/N61181918L1-1) for more HDX system information.The DS3-PSM installs into a single multiplexer slot (slot A in a non-redundant configurationor slots A and B in a redundant configuration) in the Total Access 3000 chassis and interfacesto the network via the BNC I/O module (P/N 1181004L1) attached to the lower right corner ofthe backplane. Utilizing one DS3-PSM provides a reliable, high-speed network connection.Two DS3-PSMs used in conjunction with two ESMs provide Automatic Protection Switching(APS) capability; one unit is online, the other is in standby.ATMThe following standard traffic types are supported for data and Voice over DSL (VoDSL)services:• CBR• rtVBR• nrtVBR• UBRThe DS3-PSM employs traffic prioritizing and policing on a per VC (Virtual Circuit) basis toensure proper delivery of customer data. Efficient data delivery is maximized through earlypacket discard and partial packet discard. Substantial buffers are also utilized to optimizedata throughput.Table 1. HDX Core Switching EquipmentDescription Part NumberDS3 Primary Switch Module (DS3-PSM ) 1181041L3Expansion Switch Module (ESM) 1181046L1Primary Controller Unit (PCU) 1181918L1Expansion Controller Unit (ECU) 1181919L1
