What is SIP Trunking?
SIP (Session Initiation Protocol) trunking enables businesses to make and receive calls over the internet rather than traditional telephone lines.
A SIP trunk acts as a virtual connection between your phone system and the wider telephone network, replacing ISDN and analogue lines with a more flexible solution that supports modern business communications.
Whether you’re retaining an on-premise PBX or integrating with a Unified Communications platform, SIP trunking provides a straightforward route to modernising your telephony environment.
Benefits of SIP Trunking
Reduced Communication Costs
Eliminate expensive line rental costs and benefit from lower call charges compared to traditional telephony services.
Scale as Your Business Grows
Quickly add or remove call channels as your requirements change without installing additional physical lines.
Improve Business Continuity
Automatic failover and call routing help keep your organisation connected during outages and disruptions.
Simplify Management & Integration
Connect SIP services to your existing PBX, MS Teams, UC platform or contact centre solution, while consolidating voice services with a trusted provider for simpler management and support.
How SIP Trunking Works
SIP trunking converts voice calls into digital data and securely transports them over your internet connection.
A typical deployment includes:
- Existing PBX or Unified Communications Platform
- Session Border Controller (SBC)
- SIP Trunk Service
- Public Telephone Network or External Endpoints
The Session Border Controller (SBC) provides additional security, call control and performance management, helping protect your voice services and maintain reliable connectivity.
SIP Trunking Services from SCG
Whether you’re replacing ISDN services, supporting hybrid workers or improving telephony resilience, SCG delivers SIP trunking services tailored to your organisation.
Flexible Call Capacity
Scale concurrent call paths to match your business demand.
Contact Number Flexibility
Retain existing numbers or deploy new numbering across the UK.
Built-In Resilience
Failover and routing options help maintain service availability and minimise disruption.
Secure Voice Services
Encryption, fraud prevention and secure connectivity help protect your communications and reduce risk.
Number Porting Support
Expert guidance throughout the migration process.
UK-Based Support
Access experienced engineers and support teams whenever you need assistance.
Our Simple SIP Migration Process
- Assess
Review your existing telephony environment and requirements. - Design
Design the right SIP solution for your business. - Migrate
Port numbers and deploy services with minimal disruption. - Optimise
Monitor performance and provide ongoing support
Our experienced team manages the migration process from planning through to deployment, helping minimise downtime and operational disruption.
SIP Trunking: Built for Modern Organisations
Contact Centres
Multi-Site Businesses
Professional Services
Healthcare & Public Sector
Retail & Hospitality
Hybrid & Remote Workforces
Ready to Modernise Your Business Communications?
Reduce costs, improve resilience and future-proof your telephony with SIP trunking services from SCG.
FAQs
SIP trunking delivers voice calls over internet connectivity instead of traditional physical telephone lines.
Pricing varies depending on the number of channels, usage requirements and resilience options selected.
The number required depends on how many simultaneous calls your business expects to handle during peak periods.
Yes. SIP trunking solutions incorporate security measures such as encryption, fraud protection, monitoring and Session Border Controllers (SBCs) to help protect business communications.
Most businesses require a SIP-enabled PBX, compatible Unified Communications platform or SBC. SCG can help assess compatibility.
In many cases, yes. SIP trunking integrates with a wide range of on-premise and Cloud-based communication platforms.