SIP trunking connects the phone system you already own to the public telephone network over your internet connection, instead of through traditional phone lines. You keep your PBX, your phones and the way your team works, and FastPBX carries your calls. It’s the simplest way to move an on-premises phone system to VoIP without replacing it.
What is a SIP trunk?
SIP (Session Initiation Protocol) is the standard VoIP phone systems use to set up calls. A SIP trunk is a virtual connection between your PBX and a provider like FastPBX. Calls travel over the internet as data, and FastPBX connects them to any phone number, landline or mobile.
Traditional phone lines (analog lines or PRI circuits) are physical connections, each with a fixed capacity and a monthly bill. A SIP trunk replaces them with a connection that runs over the internet service you already pay for.
Benefits of SIP trunking
- Keep your phone system. Protect the investment you’ve made in your PBX and phones, and keep the call flows your team knows.
- Lower phone line costs. Stop paying for physical lines and circuits you may not fully use.
- Keep your numbers. We port your existing business numbers, so customers keep calling the numbers they know. You can also add new local, toll free or vanity numbers.
- Scale as you grow. Add capacity when you hire or open a location, without waiting for a new line to be installed.
- 24/7 U.S.-based support. Our team helps you connect your PBX and stays available after you go live.
SIP trunking or a hosted PBX?
SIP trunking suits businesses that already own a PBX and want to keep it. If your phone system is aging, or you’d rather not maintain one at all, a hosted PBX may be the better fit: the phone system lives in FastPBX’s cloud, and you get features like auto attendant, extension dialing and call recording with no equipment to maintain. Plans start at $19.95 per extension per month; compare plans.
Not sure which you need? Tell us about your current setup with the form below, and a cloud specialist will help you choose.
How to get started with SIP trunking
- Tell us about your phone system: your PBX, how many calls you handle at once, and which numbers you use.
- Get a quote based on what your business needs.
- Connect and port. We help you configure your PBX and port your numbers to FastPBX.
SIP trunking FAQ
Do I need to replace my phones?
No. SIP trunking connects to your existing PBX, so your phones keep working as they do today.
Can I keep my phone numbers?
Yes. We port your existing business numbers to FastPBX.
What do I need for SIP trunking?
A PBX that supports SIP (or a gateway that adds SIP to it) and a reliable internet connection. Our support team can check your connection and help set up Quality of Service (QoS) on your router so calls stay clear.