SIP Trunking
SIP trunking is a method of delivering telephone services over the internet using the Session Initiation Protocol (SIP). It connects your private phone system (PBX) to the public switched telephone network (PSTN) without traditional phone lines.
Why SIP Trunking Matters to Your Small Business
Traditional phone lines charge per line, per month—regardless of usage. A business needing five simultaneous call capacity pays for five lines even if they rarely use all five at once. SIP trunking changes this by delivering calls over your internet connection, often at lower per-minute costs with more flexibility.
Beyond cost savings, SIP trunking enables features that traditional lines cannot provide. You can easily add or remove call capacity, keep your phone numbers when moving locations, and integrate with modern business tools. It is the bridge between old phone systems and new cloud communications.
For small businesses, SIP trunking matters because it levels the playing field. You get enterprise-grade phone capabilities without enterprise-grade infrastructure costs. Combined with AI phone services, you can build a professional communication system for a fraction of what large companies spend.
How SkipCalls Works With SIP Technology
SkipCalls uses SIP technology behind the scenes to handle your calls. When you forward your business number to SkipCalls, the call travels over SIP connections to our AI systems. This allows us to provide high-quality voice AI conversations, real-time transcription, and instant call summaries—capabilities that would be impossible with traditional phone line technology.
Related SkipCalls Features:
- •HD Voice Quality
- •Real-time Transcription
- •Call Recording
- •Number Porting
How SIP Trunking Works
SIP (Session Initiation Protocol) handles call setup, management, and termination over IP networks. A SIP trunk is essentially a virtual phone line delivered over the internet. Your PBX connects to a SIP trunking provider who routes calls to and from the PSTN. Codecs compress voice data for transmission, with G.711 providing toll-quality audio and G.729 offering better compression for bandwidth-limited connections.
Real-World Examples
A small office replacing expensive phone lines
A 10-person office paying $500/month for five phone lines switches to SIP trunking. They now pay around $100/month for the same capacity with better features like auto-attendant and call recording included.
A business with seasonal call volume
A tax preparation firm needs 10 lines during tax season but only 2 lines the rest of the year. SIP trunking lets them scale capacity up and down rather than paying for peak capacity year-round.
A company moving to a new location
Rather than getting new phone numbers at the new address, the business keeps all existing numbers. SIP trunking makes phone numbers portable—they work anywhere with internet access.
Frequently Asked Questions
What is the difference between SIP trunking and VoIP?
VoIP is the broad technology of voice calls over the internet. SIP trunking is a specific way to connect a business phone system (PBX) to the phone network using VoIP. Think of SIP trunking as a business-grade VoIP connection for companies with their own phone systems.
Do I need special equipment for SIP trunking?
You need a SIP-compatible PBX (most modern phone systems support SIP) and sufficient internet bandwidth. Many businesses already have both. Cloud-hosted phone systems eliminate even this requirement by handling everything in the cloud.
How much bandwidth does SIP trunking require?
Each concurrent call needs about 100 Kbps of bandwidth. A business wanting 10 simultaneous calls should have at least 1 Mbps of dedicated upload bandwidth. Most business internet connections easily handle this.
Is SIP trunking reliable for business calls?
With a stable internet connection, SIP trunking matches or exceeds traditional phone line quality. Many providers offer 99.99% uptime guarantees. For critical reliability, businesses can maintain a backup traditional line or use a secondary internet connection.
Related Terms
Modern Phone Technology Made Simple
Skip the complexity of managing SIP trunks and PBX systems. SkipCalls handles your calls with AI—just forward your number and let us do the rest.
