SIP Trunk
A SIP trunk connects your company's PBX to the public telephone network over IP. GBC supplies both the trunks and the numbers in Finland and across the EU — including porting the numbers you already use, with no break in service.
The basics
A SIP trunk carries voice calls over an internet or data connection instead of traditional ISDN lines. It replaces physical phone lines with a software-defined connection whose capacity you can change without new circuits or hardware.
A single SIP trunk carries all of your company's numbers: the main switchboard number, direct dial numbers for staff, service numbers and local numbers in other countries. Adding number ranges does not require a new line.
The number of simultaneous calls goes up or down with a contract change. Seasonal peaks and campaigns no longer mean provisioning new lines.
Because voice travels over IP, your phone system is not tied to one site. Offices, remote staff and a PBX in a data centre or the cloud all use the same connection.
Fixed line rental disappears and call rates are typically lower. You pay for the capacity you reserve and the minutes you use, not for hardware you have to maintain.
Numbers and coverage
We supply the phone numbers and the SIP trunks together. Your company can hold a local number in several EU countries and route every call into one and the same phone system.
Use cases
A SIP trunk is voice connectivity, not a phone system. It plugs into whatever system you already run — or into our mobile PBX if you do not have a PBX of your own.
An IP PBX running in a data centre or the cloud — Asterisk, FreePBX, 3CX or a vendor appliance — reaches the public network through the SIP trunk.
Many CRM and ERP platforms have a switchboard built in. A SIP trunk gives it numbers and voice connectivity, so calls are logged straight against customer records.
Teams connects to the public telephone network through certified AudioCodes Direct Routing, so Teams users make and take calls on your company's own numbers.
If you have no PBX, or want to retire the one you have, the SIP trunk can terminate directly on our mobile PBX. Phone system and voice connectivity then come from one supplier.
Technical details
The trunk is built on industry standards, so it is compatible with practically any SIP-based phone system.
Add-on services
Alongside the connection itself, you can add the services that many phone systems simply do not include.
Recording with automatic transcription and written summaries. Recordings and transcripts are searchable from the portal.
Call menus that route each caller to the right team or person.
National service numbers for customer support and sales.
Send and receive text messages by email or through the API.
Inbound faxes arrive as email; outbound faxes are sent from the browser.
APIs for call data, transcription and speech recognition, so calls can become part of your own application or CRM.
Getting started
We go through your current numbers, your PBX, how many concurrent calls you need and your network connection.
You get a written quote itemising capacity, numbers and call rates.
The trunk is opened for testing alongside your current connection, and calls are verified in both directions.
Numbers are ported at the agreed time, and our support team watches the traffic through the cut-over.
FAQ
A SIP trunk is a voice connection over an IP network that links your company's PBX to the public telephone network. Instead of traditional ISDN lines, calls travel over a data connection, so capacity can be added or reduced without installing new physical circuits.
Yes. Finnish geographic numbers, national service numbers and mobile numbers can all be ported. We handle the transfer between operators and agree the cut-over time so that no calls are lost.
We supply phone numbers and SIP trunks in Finland and across the EU. In practice your company can hold a local number in several countries and route every call into the same phone system.
A stable internet connection with enough headroom, and prioritisation for voice traffic. Budget roughly 100 kbit/s per concurrent call in each direction. The connection can be secured with TLS and SRTP and authenticated either by IP address or by SIP registration.
Yes. Teams is connected to the public telephone network with Direct Routing through a certified AudioCodes interface, so Teams users make and receive calls on your company's own numbers.
Next step
Tell us how many concurrent calls you need, which numbers are in use and which system the trunk should terminate on. You will get a written quote with pricing.