SIP Trunking for Business
Connect your PBX to the public telephone network over an IP connection, with flexible calling capacity and service options.
What Is SIP Trunking?
SIP trunking connects a business phone system to the public switched telephone network (PSTN) over an IP network. Session Initiation Protocol (SIP) establishes and manages communications sessions.
A SIP service supports incoming and outgoing calls through a compatible PBX. Capacity can be adjusted to meet changing call volumes without adding traditional phone lines.
SIP trunking can modernize an existing PBX and support unified communications. Our team can review your equipment, network, and calling requirements to plan the transition.
How SIP Trunking Works
A SIP trunk links your business phone system with an internet telephony service provider. The diagram shows how calls travel between your system and external numbers.
Voice is transmitted as digital packets over an IP connection. Your provider connects those calls to the public telephone network.
Switching to SIP Trunking
Review these requirements before deployment:
- Internet connection: Review bandwidth and connection quality for your call volumes.
- Compatible PBX: Confirm SIP support or discuss a hosted PBX alternative.
- Phones and softphones: Use compatible SIP devices or supported adapters.
- Local network: Configure networking for your phones and internal calling features.
Direct Inward Dialing Numbers
Direct inward dialing (DID) numbers let callers reach specific users or departments through your phone system.
How DIDs Work
- Your provider assigns DIDs to the appropriate destinations in your phone system.
- Incoming calls route to the configured user, department, or service.
- Multiple numbers can share a SIP service. Pricing and capacity depend on your plan.
Is SIP Trunking Right for Your Business?
SIP trunking offers an IP-based alternative to traditional PRI connections. Consider your calling costs, capacity, network, and equipment when evaluating a move.
- Are you overpaying for unused call capacity?
- Are equipment maintenance costs increasing?
- Does your current system meet your call-quality and reliability needs?
- Do you need to support remote or mobile users?
IPVoice Plus can help you assess compatibility, capacity, and service options for your business.
Key Benefits
SIP trunking can simplify capacity management, connect locations, and support business continuity options.
1. Manage Calling Costs
Choose service and capacity options that match your call volumes. Review metered and unmetered plans, usage charges, and equipment requirements with your provider.
2. Support Flexible Call Handling
Use supported routing and forwarding features to direct calls to users, offices, or mobile devices.
3. Adjust Capacity
Scale calling capacity as your business changes, subject to your network and service requirements.
4. Plan for Continuity
Explore alternative routing and failover options to help maintain access when a location or connection is unavailable.
Plan for Call Quality
Latency, jitter, and packet loss can affect voice quality. Review bandwidth, network configuration, and quality-of-service (QoS) settings with your technical team before deployment.
Choose the Right Service
Compare pricing, capacity, number porting, call-management features, security options, and support. Select a provider and service configuration that fit your business requirements.
PRI, SIP Trunking, and VoIP Compared
These technologies differ in how they connect calls, scale, and support business features.
- Feature
- PRI
- SIP Trunking
- VoIP
Technology
Traditional phone lines
Internet Protocol (IP)
Internet Protocol (IP)
Scalability
Limited, requires additional physical lines
Highly scalable, no physical line limitations
Highly scalable, no physical line limitations
Cost
Higher costs for maintenance and scaling
Lower costs, no physical line expenses
Lower costs, no physical line expenses
Mobility
Limited to physical locations
Supports remote workers and mobility
Supports remote workers and mobility
Features
Basic voice calling
Depends on the specific protocol used (e.g., SIP)
Advanced features like video conferencing, integration with business apps
Flexibility
Capacity tied to physical connections
Flexible, adaptable to changing needs
Flexible, adaptable to changing needs
Long-Term Planning
May become obsolete as telecom providers phase out support
Uses IP networks; depends on platform support
Uses IP networks; depends on platform support
Getting Started
Start with a review of your current system and calling requirements.
Who Can Benefit?
SIP trunking may suit businesses with high or variable call volumes and changing capacity requirements.
- High call volumes
- Changing capacity requirements
- A need for additional call-management features
Setting Up SIP Trunking
Confirm PBX compatibility, review network readiness, and choose suitable phones or adapters. Your service provider can then help configure trunks, routing, and number transfers.
