Telephone

Modern voice, on the network you already have.

VoIP PBX, SIP trunks, DECT roaming and IP door-entry. We move you off ageing ISDN onto a flexible system that pairs with your data network and your KNX for free.

Discipline
Telephone

Available now

What's included

Everything in one quote.

Below is the full scope of what we deliver under the telephone banner. Most clients pick a subset — we'll talk through which parts make sense for your building and budget on the first visit.

Cloud / on-prem PBX

3CX, Yealink, AVM FRITZ! and Auerswald — we install whichever fits your shape best, and run the dial-plan with you.

SIP trunking

Move off ISDN to SIP trunks with number porting. Lower per-minute rates, more flexible routing, future-proof.

DECT roaming

Site-wide cordless coverage with hand-over, multi-cell base stations and rugged handsets for hospitality and industrial.

IP door-entry

Behnke and 2N door panels that ring your desk phone, your mobile and your wall panel — all at once.

Our process

From walk-through to handover.

STEP 01

Audit

Existing extensions, lines and feature usage — plus how your team actually uses them.

STEP 02

Design

Dial-plan, hunt groups and porting schedule. Hardware list mapped to budget.

STEP 03

Install

PBX commissioned, handsets provisioned, trunks tested. Number port scheduled at the right time.

STEP 04

Train

On-site walk-through with your team, plus printed quick-start cards on every desk.

Case study

Family-run dental practice migration

Three-site practice was paying for ten ISDN channels they only needed at peak. We ported numbers to SIP, cut their line rental by 62%, and added DECT handsets so dentists answer back-of-house calls without leaving the chair.

Why clients choose us

The benefits

01 Lower line rental and per-minute costs versus legacy ISDN.
02 Works on the data network you already paid us to install.
03 Door-entry pings any device — desk, mobile, wall panel.
04 Hand-over with full dial-plan documentation; no vendor lock-in.
05 Number porting handled end-to-end with zero downtime in 95% of cases.

Common questions

You asked, we answered.

Don't see your question? Drop us a line — a real engineer will reply within one working day.

ISDN is still being switched off, right?

Yes — most German operators are completing the IP migration. Switching now is cheaper than a forced migration later.

Can I keep my existing numbers?

Yes. Number porting is part of every move and we schedule it for off-hours so you have no downtime.

What happens to the door-entry intercom?

IP door panels integrate with the PBX and ring multiple devices simultaneously. The old analogue intercom is replaced as part of the same project.

Cloud or on-prem PBX?

Most clients save money on cloud. On-prem makes sense if you have very large call volumes or sensitive data. We quote both.

Let's Talk

Time to retire the old phone system?

No-pressure site visits. Itemised quotes. Honest timelines.