Racal Excalibur ISX 5312 DTE Multiplexer DSla T1 Networking For Parts

Racal Excalibur ISX 5312 DTE Multiplexer DSla T1 Networking For Parts

The Racal Excalibur ISX 5312 is a desktop DTE multiplexer from Racal Datacom, designed for wide-area network (WAN) data aggregation and DTE-level multiplexing across T1 and similar digital circuits. The front LCD panel in the photos displays "Excalibur ISX 5312-5 DSla Red," indicating a DSla (DS-1a) configuration, consistent with T1/fractional T1 WAN applications. This unit is being sold as-is for parts or repair — the required external power supply (Racal part number 25C168-01) is not included and is no longer in our inventory.

Specifications & What's Included

• Manufacturer: Racal (Racal Datacom)
• Model: Excalibur ISX 5312
• Type: DTE Multiplexer
• Configuration shown on LCD: ISX 5312-5, DSla (DS-1a / T1 level)
• Form Factor: Desktop / tabletop enclosure
• Front Panel: Backlit LCD display, 4 numbered channel buttons, Escape, Top, User, Test, and navigation (◄ ►) buttons, Sync and Error indicators
• Rear Panel: DIN-style power connector, RJ-style port, two DB-style (DB-25 / DB-37 style) data connectors, power on/off toggle switch
• Required Power Supply: Racal 25C168-01 — NOT included
• Unit only — no power supply, no cables, no documentation included

Applications

The Racal Excalibur ISX series multiplexers were WAN access devices developed by Racal Datacom — a major player in enterprise and carrier-grade data networking equipment through the 1980s and 1990s. Multiplexers of this type aggregate multiple lower-speed DTE data streams (from serial devices, terminals, or other DTEs) across a single high-speed digital circuit such as a T1 (DS-1, 1.544 Mbps) or fractional T1 link, making efficient use of leased-line bandwidth. The ISX 5312 was aimed at enterprise WAN environments where multiple branch locations or data terminals needed to share a single T1 circuit. The "DSla" designation on the LCD references a DS-1a framing configuration, pointing to its use in North American T1 carrier applications. Racal Datacom equipment was widely deployed in corporate networks, government installations, and telecommunications infrastructure of this era. Units like this are now primarily sought by collectors of vintage networking hardware or engineers maintaining legacy WAN infrastructure.