Chapter 6. Configuration

The primary usage for SAP is general purpose asynchronous rate adaptation in a dial-up or leased environment. SAP only oper- ates on a 64 kbps data link. Figure 6-21 illustrates the menu path for selecting SAP.

FALLBACK

The FALLBACK asynchronous rate adaptation protocol provides the capability to automatically establish calls with other ISDN terminal adapters and Switched 56 DSUs, as well as other ISUs using a single configuration. The ISU 2x64 must be optioned as follows for FALLBACK operation:

1.Any asynchronous bit rate up to 115.2 kbps which is support- ed by the DTE.

2.Flow control must be enabled and supported by the DTE.

FALLBACK supports the following protocols based on the Call Type: BONDING mode 1, V.120, and T-Link. Figure 6-21 illus- trates the menu path for selecting FALLBACK.

When answering calls, the ISU 2x64 uses the incoming call type to determine which rate adaptation protocols to support.

 

 

Table 6-A

 

 

Rate Adaptation Protocols

 

 

 

Call Type

Rate Adaption Protocols

Typical Units Supported

Supported

 

 

 

 

 

Data 64 k

Bonding mode 1

ISUs

 

V.120

ISDN TAs

 

PPP async-sync

PPP compatible bridges/routers

Data 56 k

BONDING mode 1

ISUs

 

V.120

ISDN TAs

 

PPP async-sync

PPP compatible bridges/routers

 

T-Link

2-wire Switched 56 DSUs

 

 

 

60

ISU 2x64 Dual Port ISDN Service Unit User Manual

61200051L1-1D

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ADTRAN 61200051L1, 1200051L6 Rate Adaptation Protocols, Call Type Rate Adaption Protocols Typical Units Supported