SIP Trunking
Connect your phone system to public telephony and prepare its migration.
Session Initiation Protocol (SIP) supports calls over IP. For compatible phone systems, review numbers, countries and simultaneous calls.
Numbering, emergency services, portability, codecs and features vary by country and platform.
Let’s talk
How it works
Modernise telephony while retaining control of numbers, quality and continuity.
Customer PBX
SBC / SIP trunk
Telephone networkEstablish the call and carry the voice
The PBX or compatible platform exchanges SIP signalling with Colt at the agreed demarcation. The session border controller (SBC) governs interconnection; audio uses media flows that also need a working path.
A ringing call with no sound may have working signalling but blocked audio. Validate addresses, ports, NAT, codecs and SBC ownership.
Customer PBX
SBC / SIP trunk
Telephone networkQuality and concurrency
Size simultaneous calls, not just numbers. Analyse loss, latency and jitter, distinguishing channel-limit rejection from audio degradation.
QoS needs consistent treatment across controlled segments. LAN priority does not guarantee quality across arbitrary Internet paths.
Customer PBX
SBC / SIP trunk
Telephone networkKeep receiving calls
Design alternatives for access, SBC or PBX failure: trunk routing, a second destination or inbound diversion according to available options. Test detection and restoration.
Restoring new calls does not guarantee preserving ongoing calls. The pilot covers inbound, outbound, authorised emergency-call procedures and normal restoration.
Illustrative case: from situation to decision
- Situation
- A phone system must migrate while retaining numbers eligible for porting.
- Option
- Plan countries, concurrent channels and porting phases with the compatible platform.
- Check
- Test inbound and outbound calls, two-way audio and recovery before each phase.
Validate numbering, emergency calling, porting, codecs and resilience by country and platform.
Decisions for your project
- Countries and numbers
- Porting, caller ID, location and emergency-calling obligations.
- Interconnection
- PBX/SBC, codecs, agreed encryption, channels and media.
- Continuity
- Access, alternative destinations and failure/restoration tests.
From design to operation
Inventory numbers and PBXs; test a pilot block before phased number porting.
Complements, alternatives and variants
Product sources
What challenge would you like to solve?
Tell us what is happening and what needs to change. You do not need to know the catalogue.
What happens next?
- Understand the context
What’s changing, where your teams work and what cannot fail. Still defining the brief? We can help structure it.
- Design the options
Bring needs, Colt capabilities and technical criteria together. Compare alternatives and explain dependencies and limits.
- Validate before committing
Coverage, feasibility, responsibilities and terms. A commercial proposal is developed with the relevant specialists.
ColtPlatinum guides the project and coordinates commercial discussions and follow-up. Colt validates feasibility, enters into the service contract, and provisions, installs and delivers the services.
Availability, coverage, capabilities, SLAs and timelines are subject to technical validation and contract. No diagram is a service guarantee.