ISDN Services Units (ISUs)

ISU 128

The ADTRAN ISU 128(TM) is a stand alone ISDN service unit that connects data terminal equipment directly to the ISDN network. The ISU 128 includes NT1 network termination and terminal adapter functionality. The unit can be viewed as an ISDN modem that provides cost-effective, high speed data transmission at rates up to 128 kbps. Synchronous data transfer rates from 2400 bps to 128 kbps and asynchronous rates from 300 bps to 115.2 kbps are supported through a V.35 or RS-530 interface (both present on the backpanel). For speeds over 64 kbps, the industry standard BONDING protocol is used to aggregate the two 64 kbps B channels. Dialing is accomplished by using the front panel, stored numbers, DTR assertion, AT commands, V.25 bis, or the RS-366 dial interface. By using the ISU 128, the user can migrate ISDN into the existing network services and data communications equipment. The ISU 128 interoperates with Switched 56 DSUs as well as various ISDN Terminal Adapters, BONDING inverse multiplexers, and V.32 bis modems (optional). The ISU 128 is also available in SMART 16 rackmount units.

ISU 128, U-Interface ----- 1200029L2
ISU 128, U-Interface w/ V.3 2bis ----- 1200029L3
ISU 128 (RM), U-Interface ----- 1200087L1
ISU 128 (RM), U-Interface w/ V.32 bis/V.42 bis ----- 1200087L2
ISU 128 (RM), S-Interface ----- 1200087L3
ISU 128 (RM), S-Interface w/ V.32 bis/V.42 bis ----- 1200087L4

Click here to download a pdf format brochure of the ISU 128.

ISU 128 is a trademark of ADTRAN, Incorporated.

ISU 2x64

The ISU(TM) 2x64 is a dual port version of the ISU 128. It is available with or without an integrated NT1. The ISU 2x64 can be viewed as a dual modem that simultaneously and independently supports two applications at up to 64 kbps on each DTE interface. For high speed applications over 64 kbps, a single DTE interface can achieve up to 128 kbps using the BONDING protocol. The ISU 2x64 provides dual RS-530/RS-232 DTE interfaces. An RS-530-to-V.35 adapter is available to support V.35 DTE interfaces. Synchronous data transfer rates from 2400 bps to 128 kbps and asynchronous rates from 1200 bps to 115.2 kbps are supported on a single DTE interface. Synchronous data transfer rates from 2400 bps to 64 kbps and asynchronous rates from 300 bps to 57.6 kbps are supported when using dual DTE interfaces. Dialing from the ISU 2x64 is accomplished by using the front panel, stored numbers, DTR assertion, AT commands, V.25 bis, or the dual RS-366 dial interfaces.

ISU 2x64, U-Interface ----- 1200051L1
ISU 2x64, S-Interface ----- 1200051L2
RS-530 to V.35 Adapter ----- 1200072L1

Click here to download a pdf format brochure of the ISU 2x64.

ISU is a trademark of ADTRAN, Incorporated.

ISU Express

The ISU(TM) Express looks and feels like an analog modem but it uses a high speed ISDN line. It allows data transfer at rates up to 128 kbps, thirteen times faster than a standard V.32 analog modem. This unit is a scaled-down version of the ISU 128(TM) and is specifically designed as a low cost solution for applications such as high speed modem replacement, telecommuting, and remote office interconnection. For remote office applications, the ISU Express is available with an optional telephone interface for an analog telephone and/or a FAX machine connection. The ISU Express is also optionally equipped with an integrated V.32 bis/V.42 bis modem for analog modem interoperability. The ISU Express transmits data over an RS-232 interface and performs at synchronous data transfer rates to 128 kbps and asynchronous rates to 115.2 kbps. At rates over 64 kbps, the BONDING delay equalization protocol synchronizes data over the two 64 kbps B channels. ISDN network termination is designed into the unit, eliminating the need and expense of an extra NT1. For interoperability, the ISU Express supports many rate adaption protocols including Clear Channel, CCITT V.120, BONDING, T-Link, ADTRAN DSU 57.6, Fallback, and Async-to-Sync PPP. Configuration of the unit is achieved using a VT 100 menu system and AT commands. Dialing is initiated in-band over the RS-232 interface using AT commands, V.25 bis, or DTR assertion. The front-panel contains LED indicators for power, network readiness, DTE interface leads, Ring Indication/Off Hook status, and local and remote loopback testing

ISU Express, data only ----- 1200081L1
ISU Express, with V.32 bis/V.42 bis modem option ----- 1200081L2
ISU Express, with POTS telephone interface ----- 1200081L3
ISU Express, with POTS interface and modem ----- 1200081L4

Click here to download a pdf format brochure of the ISU Express.

ISU and ISU 128 are trademarks of ADTRAN, Incorporated.

ISU 512

The ISU(TM) 512 is the newest edition to the ADTRAN family of Basic Rate ISDN Service Units (ISUs). The ISU 512 is a basic inverse multiplexer that provides cost-effective, high speed data transmission for a single application at rates up to 512 kbps. It is the industry's first low cost inverse multiplexer. The ISU 512 is specifically designed for applications such as videoconferencing, high speed LAN/WAN connectivity, high speed file transfer, audio broadcasting, and T1 backup. Data terminal equipment is connected directly to the ISDN network using the ISU 512 and up to four Basic Rate ISDN lines. ISDN network termination is designed into the unit, eliminating the need and expense of up to four NT1s. The ISU 512 transmits data over either the RS-530 or V.35 interface and performs at synchronous data transfer rates from 2400 bps to 512 kbps. At rates over 64 kbps, the BONDING Mode 1 inverse multiplexing protocol synchronizes data over up to eight 64 kbps B channels. By supporting BONDING Mode 1, the ISU 512 interoperates with other BONDING-compatible inverse multiplexers and ISDN terminal adapters. Configuration of the ISU 512 is achieved using the front panel keypad or a VT 100 menu system. Dialing from the unit is accomplished by using the front panel, stored numbers, DTR assertion, AT commands, V.25 bis in-band, or the RS-366 dial interface.

ISU 512 ----- 1200086L1
For 122/128 kbps dual-port videoconferencing applications these cables may be necessary:

RS-530 to V.35 adapter cable ----- 1200072L1
RS-366 "Y" cable ----- 1200120L1

Click here to download a pdf format brochure of the ISU 512.

ISU is a trademark of ADTRAN, Incorporated.