What is VoIP – and what is SIP?
VoIP stands for "Voice over IP": speech is digitised and sent over the internet in data packets. SIP (Session Initiation Protocol) is the standard that phones, phone systems and providers use to set up and end calls. A "SIP trunk" is the connection between a phone system and a provider – today's equivalent of the exchange line.
In Switzerland this has long been everyday reality: the major providers have moved their landline networks to All-IP, and analogue and ISDN lines are a thing of the past. So the question for an SME is no longer whether it makes calls over the internet, but how well the solution fits the business.
Which options are there for SMEs?
Cloud phone system
The phone system runs as a virtual PBX in the provider's data centre, ideally in Switzerland. All that remains in the office are the phones, plus apps for mobile and computer. There is no hardware of your own for the system, the provider takes care of updates, and new workstations are set up quickly. For most small businesses, this is the simplest solution.
Your own phone system with a SIP trunk
A phone system such as 3CX runs on your own server or in your own cloud instance and is connected to the provider via a SIP trunk. This pays off if you need particular workflows – such as call queues, many extensions or integration with industry software – or if you already have a system in place.
Calling in Microsoft Teams
If you already work with Microsoft 365, you can make calls directly in Teams: on your computer, on your mobile and with compatible desk phones. This requires a Teams Phone licence and a provider that connects your calls to the phone network. The advantage: chat, meetings and phone all live in a single application.
| Option | Needed on site | Suits |
|---|---|---|
| Cloud phone system | phones or apps only | most small businesses |
| Own system with SIP trunk | server or own cloud instance, phones | particular workflows, existing systems |
| Microsoft Teams | just computers, mobiles or Teams phones | businesses that work with Microsoft 365 |
What does my business need for VoIP?
- A stable internet connection. A call needs around 100 kbit/s in each direction. Low latency and as little packet loss as possible matter more than bandwidth. A fibre, cable or DSL connection is usually more than enough.
- A correctly configured router. Many routers have a feature called "SIP ALG" that tends to disrupt calls rather than help. Typical symptoms are calls where only one side can hear anything, or calls that drop after a few seconds. We check your router and firewall and give voice traffic priority (QoS) where needed.
- Suitable devices. Desk phones at the workstation, cordless DECT phones for the warehouse and workshop, or apps on mobiles and computers. Desk phones with PoE (Power over Ethernet) draw their power directly through the network cable.
- A plan for outages. If the power or internet goes down, the office phones go down with it. With automatic forwarding to mobiles, your business stays reachable all the same.
Can I keep my phone number?
Yes. Existing numbers can be ported to the new provider, including whole number blocks. Porting needs some lead time; we schedule the switchover so that your business stays reachable throughout.
Important: don't cancel your existing phone line yourself beforehand. Otherwise the numbers can be lost – the switch is handled through the porting process.
Do emergency calls work over VoIP?
Yes. The emergency numbers 112, 117, 118 and 144 can also be reached over VoIP. The location transmitted is the one registered with the provider for the number – usually the company address. Anyone using the office phone or the app while working from home or on the road should be aware of this and give their own address in an emergency.
Which features do SMEs use most?
- Ring groups: a call rings for several employees at once or one after the other.
- Time-based routing: outside opening hours, an announcement or the voicemail kicks in automatically.
- Voicemail by email: voice messages arrive in your inbox as an audio file.
- Company number on your mobile: when you're out and about, you take calls in the app and call back with the company number.
- A shared phone book: on incoming calls, every phone shows the caller's name – for example with our Phonebook Service for Yealink.
How much does VoIP cost for an SME?
The costs are made up of the monthly base fee per number or user, call minutes or a flat rate, the devices and the one-off setup. Compared with traditional lines they are usually lower, especially with several locations or many international calls.
You'll find our telephony packages and prices on the Services page.
How switching works with us
- Needs analysis: how many workstations, which numbers, which workflows – and what is already in place?
- Choosing provider and solution: together we choose the right provider and option, for example with our partners sipcall and 3CX.
- Setup and testing: we configure the system, phones and router and test everything before the switchover.
- Porting: your numbers move over on the agreed date.
- Introduction and support: your team gets a short introduction, and we remain your point of contact – via remote support too if needed.