Principles of Operation4-533610-A2-GB41-70 July 1999SNA Diagnostic InterfaceThe SNA Diagnostic Interface option, which iscompatible with IBM’s LPDA-2 ( Line ProblemDetermination Aid, Revision 2 ) protocol, enablesmanagement of 3600 Series DSUs from the DCP, aParadyne NMS, IBM’s NetView management system, orall three. All DSUs on the circuit must be 3600 SeriesDSUs.This option is compatible with all other optionsavailable to the 3600 Series DSUs: DBM, TDM, andMCMP. However, the SNA Diagnostic Interface option issupported via Port 1 on a TDM or MCMP circuit card.The 3600 Series DSUs operating with the SNADiagnostic Interface option emulate IBM 5822 DSUs;although they are all data compatible, they are notdiagnostically compatible with IBM 5822 DSUs. Amixture of 3600 Series and IBM 5822 DSUs will notsupport LPDA-2 diagnostics. The SNA DiagnosticInterface option must be installed in each control andtributary DSU.The 3600 Series DSUs operating with the SNADiagnostic Interface option can respond to commandsfrom NetView or an NMS, or the DSU’s DCP. The3600 Series DSUs respond to commands from an NMS orNetView on a first-come, first-served basis. The NetViewoperator can monitor (read) DSU parameters and linestatus and can initiate tests from NetView, but cannotchange DSU configuration options (a NetViewconstraint). An NMS operator has complete control of thenetwork, and can change network configuration options aswell as access sophisticated alarm-tracking reports.The carrier-mounted Model 3611 DSU or thestandalone Model 3610 DSU can receive the SNADiagnostic Interface firmware. Either model may beconfigured as the control of a circuit that is to be managedby the NetView management system.Refer to Chapter 6 of the COMSPHERE 3600 SeriesData Service Units, Models 3610 and 3611, Operator’sGuide for configuration option information. Refer to theCOMSPHERE 3600 Series Data Service Units,Models 3610 and 3611, Dial Backup Module and SNADiagnostic Interface Options, Applications Guide foradditional SNA Diagnostic Interface information.LPDA-2 AddressingThe addressing scheme for LPDA-2 establishes arelationship between the link segments (primary circuit,extended circuit) and the remote DSUs populating thecircuit. It allows you to target a link segment or aparticular control-tributary DSU pair in the circuit fordiagnostic testing. The LPDA-2 address is independent ofthe DSU network address associated with an NMS orDCP command, although you may choose to assign thesame value to each.NOTEIn all of the illustrations, the LPDA-2addresses are shown in decimal.Assigning an Address to the Control DSUThe following rules apply to assigning the LPDA-2address to control DSUs:1. Link Segment Level 1. The control DSU closestto the NetView host is typically assigned theaddress 1 ( Figure 4-41).2. Link Segment Level 2. An extended controlDSU, if present, is typically assigned the address 2( Figure 4-42).3. Valid Addresses. Valid addresses for controlDSUs range from 1 to 255.
