ADTRAN ISU 128 - Manual (Page 21)

Chapter 1. Understanding ISDN and the ISU 128
6 ISU 128 User Manual 61202.029L2-1
RECOMMENDED OPERATING PROTOCOLS
The ISU 128 supports a wide range of operating modes. Many combinations
of circuit type, protocol, and data rate may be selected. However, only the
combinations shown in Table 1-B are recommended. As noted in Table 1-B, all
asynchronous rates will support flow control. Flow control is required when
operating at 115,200 bps using PPP (Point-to-Point Protocol), V.120, SAP (Sim-
ple Adtran Protocol), or asynchronous bonding.
Table 1-B shows that a given data rate may be achieved by more than one pro-
tocol/rate adaption selection. The table is organized so that selections with
the least transport delay are closer to the top of the table for any given circuit
type. Therefore, users should choose a protocol and rate closer to the top of
the protocol rate list for a given circuit type.