ADTRAN 1200051L1 User Manual

Also see for ISU 2x64: Using Specifications

Contents

ADTRAN 1200051L1 User Manual Manual pdf 20 page image

Chapter 1.Understanding ISDN and the ISU 2x646 ISU 2x64 Dual Port ISDN Service Unit User Manual 61200051L1-1DWhen the ISU 2x64 is used on an existing ISDN line that is notmultipoint, with one SPID or no SPID numbers, additional con-siderations should be addressed. If DTE specific operation isdesired, the ISDN line must be converted to multipoint operation(2 SPIDS). If not, the following applies:1. If a single SPID is assigned, it must be entered under SPIDDTE#2.2. When no calls are active, the first incoming call is always di-rected to DTE#2.3. DTE#1 only accepts incoming calls when a call is active onDTE#2.4. Outgoing calls can be placed without restrictions from eitherport.For applications involving only one SPID being used on a multi-point line, the SPID assigned must be entered under SPIDDTE#2. For applications involving the S/T version (part number1200.051L5 and 1200.051L6), no SPID(s) are used when the EuroISDN or VN4 switch type is selected. The call will be routed tothe appropriate port based on the directory number enteredunder the local directory number (LDN) prompt . See the sectionSetting the Terminal ID on page 32 for more detail on enteringSPID numbers.RECOMMENDED OPERATING PROTOCOLSThe ISU 2x64 supports a wide range of operating modes. Manycombinations of circuit type, protocol, and data rate may beselected. However, only the combinations shown in Table 1-B arerecommended. As noted in Table 1-B, all asynchronous rates sup-port flow control. Flow control is required when operating at115200 bps using V.120, PPP, MLPPP, SAP, or BONDING proto-cols.Table 1-B shows that a given data rate may be achieved by morethan one protocol/rate adaptation selection. The table is orga-nized so that selections with lower throughput delay are nearerthe top of the table for any given circuit type. Therefore, usersshould choose a protocol and rate nearer the top of the list for anygiven circuit type.