The TPI 550B+ ISDN BRI Test Set, illustrated below, is a compact, battery operated device used to conduct testing of ISDN circuits at the customer premise, the input and output of the ISDN repeater housing, or at the main distribution frame. The TPI 550B+ is designed both for rugged durability and ease of use, with menu driven screens. Figure 1 — TPI 550B+ ISDN BRI Test Set The TPI 550B+'s operating modes allow it to function as an NT1 (Network Termination), as TE (Terminal Equipment), as both (NT1/TE), as LT (Line Termination), or in a Monitor mode (for monitoring D channel info). It may be connected to either the DSL (Digital Subscriber Loop) U Interface or the S/T interface. It is compatible with the 2B IQ DSL interface, EBS (P-Phone) interface, and POTS Line Interface. The TPI 550B+ allows placement of additional loss on the circuit, either at the LINE U Interface or the S/T interface for margin analysis testing. The TPI 550B+ ISDN BRI Test Set allows selection of loopbacks for each of the B channels, or for the full bandwidth (2B+D). The TPI 550B+ also responds to network controlled loopbacks at the NT1. ISDN testing and measurements made by the TPI 550B+ include: f FEBE (Far End Block Errors) and FEBE Errored Seconds in all ISDN U interface modes. y Cyclic Redundancy Check (CRC) Errors and CRC Errored Seconds with 2B1Q Interface selected. y S/T FRAME Errors and Errored Seconds, and Bipolar Violations (BPV’s) and Errored Seconds on the S/T Interface in NT1 and TE modes. y Bearer Service selections. - Circuit-Switched Voice, 3.1kHz Audio - Circuit-Switched Data - B- or D-Packet > Intelligent Testing (IT) features. - Auto Bearer Service tests, Local and Distant - Auto SPID/Guess SPID - Video Test (Channel Delay and Dual BERT) - Test Macro (dial test number and run test for each Bearer service) f Dual Call Testing. y Bit Error Testing, with G.821 Results. y B channel Delay. y D channel message analysis. y Cause Messages. y Layer 1, 2, 3 States. y BRIV Support. * Pre-Qualification of Loop. - LT Emulation, generating Layer 1 2B1Q signal - Generation of 40 kHz Test Tone - Intercom mode t Optional U interface Monitor. >■ Parameter Download. * Optional Service Testing. - EBS (P-Phone) and POTS - IDSL - SDSL - Total Reach ISDN/DDS