61202129L1-1 TSU 120 User Manual 1-1Chapter 1 IntroductionTSU 120 OVERVIEWThis manual covers the use of the following products:• TSU 120• TSU 120eUnless otherwise stated, the TSU 120 refers to both products.The TSU 120 is a T1/FT1 multiplexer with an Nx56/64 V.35data port, a DSX-1 (PBX) interface, one option slot, and embed-ded SNMP management. The TSU 120e offers a built-in dialback up feature for the Nx port. The TSU 120’s option slotaccepts one of many available option modules for voice anddata applications.The TSU 120 links user data sources such as local area network(LAN) bridges and routers, computers, CAD systems, telecon-ferencing equipment, and PBXs. Through the use of multipledata ports, the TSU 120 can simultaneously connect one ormore of these devices to a T1 circuit. The amount of bandwidthallocated to each port is custom-programmable. You can manu-ally allocate bandwidth or set the bandwidth to automaticallychange at predetermined times to use the available bandwidthmost advantageously. Changes in the configuration do not dis-rupt data flow in channels that are not being reconfigured. Theunique architecture and the availability of option modules pro-vides a path for growth to accommodate future requirements.
