WHAT IS SIP TRUNKING?

SIP trunking (Session Initiation Protocol trunking) is a method of sending voice and other unified communications services over the internet, instead of using traditional phone lines.

What it Does

• Connects your business phone system (PBX) to the internet.
• Lets you make and receive calls using VoIP (Voice over IP) instead of old-school landlines.

Why It’s Called a "Trunk"

• In traditional telephony, a "trunk line" was a single line that carried many phone calls.
• SIP trunking is the modern, digital version of that — using internet bandwidth to carry multiple calls.

What You Need

• A SIP provider (also called an ITSP – Internet Telephony Service Provider)
• An IP-enabled PBX (or a regular PBX with a gateway)

Benefits

• Cost savings – lower rates than traditional phone services
• Scalability – add or remove lines easily
• Flexibility – works anywhere you have internet
• Unified communications – integrate with video, messaging, and other tools

Common Use Case

Businesses replacing their expensive PRI (Primary Rate Interface) lines or analog lines with SIP trunks to modernize and save money.