Chapter 7. Protocol Options

FALLBACK

The FALLBACK asynchronous rate adaption protocol provides the capability to automatically establish calls with other ISDN terminal adapters, Switched 56 DSUs, V.34 modems (optional), as well as other ISUs using a single config- uration. To communicate with analog modems, the ISU 128 with V.34 modem option (part numbers 1202029L3) must be used.

The ISU 128 must be optioned as follows for FALLBACK operation:

Any asynchronous bit rate up to 115.2 kbps which is supported by the DTE.

Flow control must be enabled and supported by the DTE.

FALLBACK supports the following protocols based on the call type: BOND- ING Mode 1, V.120, T-Link, and V.34.

When answering calls, the ISU 128 uses the incoming call type to determine which rate adaption protocols to support. See Table 7-A for the call type and the supported rate adaption protocols.

 

 

Table 7-A

 

 

Rate Adaption Protocols

 

 

 

 

Call Type

Rate Adaption

Typical Units Supported

 

Protocols Supported

 

 

 

 

 

 

 

 

Data 64k

BONDING Mode 1

ISUs

 

 

V.120

ISDN TAs

 

 

PPP

PPP compatible bridges/routers

 

Data 56k

V.120

ISDN TAs

 

 

T-Link

2-Wire Switched-56 DSUs

 

 

PPP

PPP compatible bridges/routers

 

Speech or Audio

V.34

V.34 compatible modems

 

 

 

 

 

54

ISU 128 User Manual

61202.029L2-1

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ADTRAN ISU 128 user manual Fallback, Rate Adaption Protocols

ISU 128 specifications

The ADTRAN ISU 128 is a versatile and robust integrated service unit designed for network access solutions, particularly within telecommunications and enterprise environments. This unit plays a critical role in enabling high-speed data transmission, supporting various voice, video, and data services over traditional and next-generation networks.

One of the noteworthy features of the ADTRAN ISU 128 is its ability to aggregate multiple digital circuits into a single access point. It supports T1, E1, and fractional T1/E1 interfaces, making it a flexible choice for customers with different bandwidth needs. The unit allows for seamless migration from legacy systems to modern broadband services, ensuring that businesses can scale their operations without significant infrastructure changes.

The ADTRAN ISU 128 also excels in its support for various protocols, including Frame Relay and ATM, providing the necessary flexibility to adapt to different network architectures. This adaptability is essential for businesses that rely on diverse communication platforms to maintain connectivity and operational efficiency.

Another significant aspect of the ISU 128 is its built-in features for diagnostics and monitoring. The unit includes comprehensive loopback and performance monitoring capabilities, which enable network administrators to troubleshoot potential issues proactively. This functionality ensures a reliable connection and minimizes downtime, which is critical for maintaining service-level agreements (SLAs).

In terms of user interface, the ADTRAN ISU 128 is designed with ease of use in mind. The unit can be configured and managed through a web-based graphical user interface, allowing for straightforward remote access to settings and performance metrics. This capability facilitates quick adjustments and upgrades, helping to streamline network management tasks.

The ISU 128 is also built with a strong emphasis on reliability and durability. It is housed in a compact, rack-mountable design, making it suitable for various deployment environments. These characteristics, combined with support for redundant power supplies, enhance the unit's reliability in critical operations.

Overall, the ADTRAN ISU 128 stands out as a powerful solution for organizations seeking to optimize their network access. With its advanced features, compatibility with multiple technologies, and emphasis on reliability, the ISU 128 is an ideal choice for those looking to enhance their communication infrastructure in a rapidly evolving digital landscape.