SIP Trunking
Cloud-hosted SIP Trunking from Claranet — connect your on-premise PBX to the PSTN over our MPLS network with resilient, feature-rich voice services supported 24x7x365.
Challenges we solve
ISDN switch-off approaching
Traditional ISDN lines are being retired. You need a reliable, future-proof alternative to connect your existing PBX to the telephone network without replacing your entire phone system.
Expensive legacy voice circuits
Dedicated voice lines are costly, especially across multiple sites. You want to consolidate voice and data over a single IP network to reduce overheads and simplify management.
Limited call handling features
Your current connectivity offers basic dial tone but lacks cloud-based features like auto attendants, call queues, call recording, and analytics that modern businesses need.
No visibility of call performance
Without integrated analytics, you can't see call volumes, patterns, or quality metrics across your organisation — making it impossible to optimise your voice infrastructure.
What is SIP Trunking?
Claranet's Hosted SIP Trunking service provides a highly resilient SIP trunk for your on-premise PBX to connect to the PSTN over Claranet's MPLS network. It replaces traditional ISDN lines with IP-based voice connectivity, delivering significant cost savings and opening up a range of cloud-based call handling features.
The service is hosted within our voice partner BT's network, based on Cisco Broadsoft technology, and your PBX platforms connect via Claranet MPLS connectivity and shared interconnects. Think of it as an overlay PBX on top of your existing system — not just a connectivity pipe, but a feature-rich cloud voice platform.
Day-to-day management is in your hands through an intuitive Business Portal, while Claranet handles the design, build, and ongoing platform support. Optional extras include call recording with PCI DSS compliant storage, integrated Tollring call analytics, and trunk failover for business-critical resilience.
Key benefits
- Replace ISDN with IP-based voice over MPLS
- Cloud-based auto attendants, ACD queues, and hunt groups
- PCI DSS compliant call recording (30-day, 180-day, or 7-year)
- Integrated Tollring call analytics
- Enterprise trunk failover for resilience
- 24x7x365 support from Claranet
Why Claranet?
Service components
SIP Trunk Channels
Basic and Premium channel licences for concurrent calls, with trunk failover on Premium.
Site Licences
Per-location licences with auto attendant, call logging, calling plans, and capacity management.
Call Recording
Cloud-hosted PCI DSS compliant recording with AES-256 encryption and pause/resume for card data.
User Licences
SIP Trunking, Functional, Fixed, and Mobile licence tiers with CRM integration bolt-ons.
Tollring Analytics
Three-tier call analytics: Insight (standard), Report (custom), and Report Premier (real-time wallboards).
Technical capabilities
MPLS voice delivery
SIP trunks are delivered over Claranet MPLS with Quality of Service (QoS) configuration to prioritise voice packets. Supports G711, G722, and G729 codecs for optimal call quality across your estate.
Enterprise trunk failover
Link multiple trunks across sites for resilient call patterns with load balancing, overflow, most idle, or least idle routing policies. Requires Premium channel licences and at least two configured trunks.
PCI DSS compliant recording
Cloud-based call recording with DTMF pause/resume for card data protection. AES-256 encryption with MD5 digital fingerprinting ensures recordings are legally admissible. Storage options: 30 days, 180 days, or 7 years.
Approved PBX compatibility
Connect Cisco, Mitel, Avaya, and other approved PBX and gateway models. BT maintains the approved equipment list including required firmware levels to ensure platform compatibility.
Number management
Full UK geographic (01/02) and non-geographic (03xx) number support. Import existing numbers via porting (single-line 4 days, multi-line 10 days, complex DDI 25 days) or provision new number ranges.
Business Portal self-service
Administrators manage users, sites, auto attendants, hunt groups, and call handling rules in real time. Near-real-time call logging with 15-minute refresh. User add/remove capability within licence limits.
Accreditations & partnerships
Certified expertise you can trust.
Ready to get started?
Replace your legacy ISDN lines with cloud-hosted SIP Trunking from Claranet. Our voice specialists will design a solution that fits your existing PBX infrastructure.