# OpenStage 15 T — Entry-level Digital Desk Phone

URL: https://www.promark.tr/en/products/openstage-15t
Category: Endpoints
Family: [OpenStage TDM Family — 15T / 40T / 60T (Legacy)](https://www.promark.tr/en/products/openstage-tdm)

Full-featured entry-level TDM desk phone connecting to OpenScape Business / OpenScape 4000 via the UP0/E digital interface, with a 2-line display and 8 LED-equipped programmable keys. Backward compatible with OptiPoint.

## Key features

- 2-line monochrome graphic display (205 × 41 pixels, fixed 30° viewing angle, no backlight).
- 8 programmable keys (red LED) — usable as line keys or speed-dial/feature keys; paper inlay labeling.
- 3 fixed function keys (red LED) + 3 navigation keys + volume +/− keys.
- Full-duplex hands-free + AEC echo cancellation.
- UP0/E digital interface + extended CorNet-TS protocol (software updated over the line).
- Expansion: max. 1 × OpenStage Key Module 15 (18 extra LED keys).
- Wall-mountable.
- Ice blue or lava color; OptiPoint backward compatibility — 1:1 swap of legacy fleet.
- Compatible with OpenScape Business, OS 4000, HiPath 3000/4000.

## Specifications

- **Line interface:** UP0/E (CorNet-TS, digital; supports software download)
- **Display:** 2 lines, 205 × 41 pixels, monochrome (fixed 30°)
- **Backlight:** No
- **Programmable keys:** 8 (red LED, paper inlay)
- **Fixed function keys:** 3 (red LED)
- **Navigation:** 3 navigation keys
- **Hands-free:** Full-duplex + AEC
- **Headset jack:** No
- **USB:** No
- **Bluetooth:** No
- **Expansion:** Max. 1 × OpenStage Key Module 15
- **Power supply (PSU):** Optional (country variant)
- **Wall mounting:** Yes
- **Dimensions (H × W × D):** 70 × 240 × 220 mm
- **Weight:** 0.777 kg
- **Color:** Ice blue or lava
- **Operating temperature:** +5 °C to +40 °C
- **Compatible PBX:** OpenScape Business, OS 4000, HiPath 3000/4000

## Use cases

- OptiPoint refresh — 1:1 replacement of legacy Optiset/OptiPoint phones without IP migration.
- OS 4000 plant facility — standard user phone where digital UP0/E infrastructure is preserved.
- Hotel/hospital TDM room phone — sites with heavy analog/digital usage; PSU or line-powered.
- Banking and public buildings — environments without IP infrastructure; red LED + 8 line keys standard.
- Emergency line — TDM backup line that keeps working without IP failover (operator arm).

## For a quote and BOM

https://www.promark.tr/en/contact · +90 312 544 0915 · destek@promark.tr