Telephony — 3CX & VoIP

3CX phone systems and business VoIP for companies

Replace your ageing phone system with business VoIP (voice over IP): a 3CX phone system hosted and administered by our teams, softphones on desktop and mobile, video conferencing and Microsoft 365 integration. We handle the porting of your numbers, the sizing of your network and day-to-day operation, for a single site or several branches — in Paris and Île-de-France.

Discuss my telephony project01 83 81 17 48
What holds you back

The patterns we keep seeing.

01

A rigid, ageing phone system

Adding a line, changing a call forward or supporting an office move means working on an installation that nobody fully masters any more. With the gradual shutdown of the legacy copper network, the question is no longer whether to migrate, but when and on what terms.

02

Missed calls away from the office

The desk phone rings in an empty office while the employee is travelling, working from home or at another site. Customers land on voicemail, teams call back from personal mobiles and the company loses track of those conversations.

03

Telephony and IT managed separately

One carrier for the lines, one installer for the phone system, one provider for the network: when call quality degrades, each points at the other. A single team operating both the telephony and the network can diagnose the full chain, from the softphone to the carrier link.

What we cover

The scope of the service.

01 / PHONE SYSTEM

Hosted and administered 3CX phone system

A 3CX instance dedicated to your company, hosted and operated by our teams: configuration, updates and changes are handled over the long term.

  • Dedicated 3CX instance, hosted and kept up to date
  • Dial plan, call forwarding and voicemail
  • Voice greetings, business hours, call queues and announcements
  • 3CX video conferencing accessible from the browser
  • Call statistics and activity monitoring
02 / DEVICES & MOBILITY

Softphones, desk phones and remote work

Your employees make and take calls on their business number from the tool that suits their role: computer, smartphone or IP desk phone.

  • Desktop softphone, integrated into the working environment
  • Mobile app: the business number follows the employee
  • IP desk phones for reception and desk-based roles
  • The same experience in the office, working from home or on the move
  • Headsets and equipment chosen to match how each role works
03 / NUMBERS & CARRIERS

Number porting and carrier links

We prepare and coordinate the porting of your existing numbers and the connection of voice links, working with the carriers involved.

  • Porting of your numbers: mandate, coordination, planned cutover
  • New numbers and direct lines (DDI, direct dial-in)
  • Sizing of simultaneous call channels
  • Carrier coordination when an incident affects a link
04 / INTEGRATION & MULTI-SITE

Microsoft 365, network and multi-site

Telephony builds on your existing environment: Microsoft 365 directory, company network and remote sites brought together in a single dial plan.

  • Microsoft 365 integration: directory, accounts and presence, depending on the features enabled
  • Coordination with Teams, depending on your usage
  • Network prerequisites: voice traffic prioritisation (QoS) and a dedicated VLAN
  • Multi-site: a single phone system with internal calls between sites
  • On-site work beyond Île-de-France through our regional partners
How we proceed

From scoping to follow-up.

The exact scope, deliverables and timelines are formalised in the proposal, before any commitment.

1
Scoping and usage audit

Analysis of your call flows, your greeting scenarios, your carrier contracts and the state of your network — internet link, cabling, Wi-Fi. This baseline is what sizes the solution.

2
Phone system design

Dial plan, call queues, business hours, call forwarding, choice of devices and single- or multi-site architecture, validated with you before any configuration.

3
Preparation and number porting

Configuration of the 3CX instance, user creation, network preparation (QoS, voice VLAN) and launch of the porting mandate with the carriers.

4
Cutover and training

A cutover scheduled in a window agreed with you and organised to limit the impact on your inbound call handling. Your teams are trained on the softphones and on day-to-day management of the phone system.

5
Operations and ongoing changes

Routine administration, employee joiners and leavers, adjustments to greeting scenarios, statistics monitoring and support for your users.

Frequently asked questions — telephony

The answers describe how the service works. Quantified commitments are formalised in your contract.

Yes — that is what number porting is for: we prepare the porting mandate, coordinate the gaining and losing carriers and schedule the cutover to limit the impact on your inbound call handling. Your existing numbers — main line, direct lines, fax numbers — are inventoried during scoping, as some specific cases sit with the carrier. The effective porting date depends on the carriers; the timetable is agreed during scoping.
No, not necessarily. 3CX works with softphones on computers and mobiles, which reduces the need for physical handsets for a large share of your staff. Existing IP phones are reviewed case by case: compatible models can be reconfigured, while the others come with a replacement recommendation planned with you.
Voice uses little bandwidth but demands a stable connection: call quality comes from the consistency of the link more than from its raw speed. We assess your access (FTTH or FTTO), your local network and your Wi-Fi during scoping, then set up voice traffic prioritisation (QoS) and, where needed, a dedicated VLAN. If the link is undersized, we tell you before the cutover, not after.
Continuity rules are configured in advance: inbound calls forwarded to mobiles or to another site, with an announcement or voicemail depending on the agreed scenario. The mobile apps remain usable as long as they have a cellular data connection. For critical sites, a second internet link can be considered; the chosen architecture is defined during scoping.
The integration covers the directory and authentication in particular: synchronisation of users and contacts, sign-in with Microsoft 365 accounts and presence surfaced according to the features enabled. Your employees find their usual contacts directly in the softphone. The exact scope is defined during scoping, based on your tenant and your usage, particularly around Teams.
The number of users and simultaneous calls, the number of sites, the devices to supply or reuse, the carrier links, the complexity of your greeting scenarios and the level of operational support. 3CX licensing is sized on simultaneous calls in particular, not only on the number of extensions. We produce a costing after scoping, formalised in the specific terms of your contract.
The timeline depends on the number of sites and users, the greeting scenarios to build, the network prerequisites and the porting lead times, which partly sit with the carriers. The cutover is scheduled in a window agreed with you, with the old system staying in service until the switch. The timetable and milestones are formalised during scoping and in your service contract.
3CX provides queue monitoring, call statistics and, depending on the configuration, call recording. These features involve personal data: informing the people concerned, purposes and retention periods are designed to fit within the applicable obligations — the legal qualification remains to be validated with your counsel. The chosen configuration is documented during scoping.
Your numbers belong to you and remain portable to the carrier of your choice; your phone system configuration — dial plan, greeting scenarios, users — is documented and handed back to you. The reversibility arrangements, including the transfer of access and support through the exit, are formalised in your service contract.
Related services

Frequently engaged together.

IVR and auto attendant for smooth call handling

Design a professional phone greeting on 3CX: IVR menus, call queues, business hours, skills-based routing and custom announcements, in Paris and Île-de-France.

3CX call center: supervision, queues and statistics

Call queues, real-time supervision, statistics, call recording, CRM integration and team support to structure your 3CX call center in Paris and Île-de-France.

Business fibre, network and Wi-Fi for companies

FTTO or business FTTH fibre, SD-WAN, multi-AP Wi-Fi, VLAN segmentation, QoS and VPN for reliable, monitored company networks in Paris and Île-de-France.

An audit, then a clear plan.

Describe your need in a minute. We come back with an assessment and prioritised next steps.

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3CX integrator: business VoIP for companies in France | Dalena