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Business Telephony & VoIP

SIP Trunks & Numbering

We size and configure SIP trunks against your real concurrent call volume rather than headcount. We coordinate number porting, set up a failover route so an outage does not leave you without a phone, and document the whole numbering scheme per department and branch.

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Who it is for

  • Businesses on ISDN or analogue lines with high line costs
  • Companies with branches and multiple published numbers
  • Organisations wanting redundancy in their telephony
  • Sites where losing the phone means losing sales

When we are NOT the right choice

  • If internet connectivity is unstable with no backup link
  • If only the lowest per-minute rate matters
  • If there is no phone system, and none is in scope

PROCESS

The process

Indicative times from signature of the proposal, subject to hardware availability. Every project is shaped to the size and the needs of the client.

  1. 01Traffic analysis

    We examine actual call traffic to size the channels. Headcount is a poor guide to concurrency.Time: 2-5 working daysDeliverable: Concurrent call estimate

  2. 02Numbering plan

    We define which numbers are published, which are internal, and how the company presents on outbound calls.Time: Alongside the studyDeliverable: Number map per department and branch

  3. 03Configuration and failover

    We configure the trunks on the phone system and define a failover route, usually to mobiles, for outages.Time: 1-3 daysDeliverable: Live trunks with a failover route

  4. 04Number porting

    We coordinate porting with the provider. The duration is set by them and is stated separately in the timeline.Time: Per provider timelineDeliverable: Ported numbers with no lost calls

  5. 05Testing and documentation

    We test inbound and outbound per number, including the outage scenario, and hand over the documentation.Time: On completionDeliverable: Numbering and test documentation

What is included

  • Traffic analysis and channel sizing
  • Numbering plan per department and branch
  • SIP trunk configuration on the phone system
  • Failover route for outages
  • Number porting coordination
  • Per-number testing and documentation

What is not included

  • Provider monthly fees and call charges
  • Provider delays in porting
  • Internet circuit upgrades
  • Commercial rate negotiation with the provider

Technology and equipment

  • SIP trunks
  • FreePBX / Asterisk
  • Yeastar
  • Grandstream
  • MikroTik RouterOS

From practice

The most common overspend in telephony is not call time, it is channels. Their number is often chosen from headcount, while actual concurrent calls at peak are considerably fewer.

The opposite mistake is more dangerous: no failover route at all. When the line goes down the phone system simply falls silent, and the lost calls are recorded nowhere for anyone to see.

Prerequisites

  • Stable internet connectivity, ideally with a backup link
  • A working phone system, or one within the project
  • Details of existing numbers and contracts
  • A decision on which numbers are ported

Cost

Configuration and porting coordination are quoted as a project. Monthly fees and call charges remain your relationship with the provider. Trunk management and numbering changes sit within the support agreement.

We do not publish a price list. Every proposal follows a site survey and separates hardware from labour.

What moves the cost

  • Number of concurrent call channels
  • How many numbers are ported
  • Whether a failover route and second link are required
  • Numbering complexity across multiple branches

Frequently asked questions

How many channels do I need?

It follows from concurrent calls at peak, not from headcount. In many companies concurrency is considerably lower than assumed, and that is where cost is saved.

What happens if the internet goes down?

That is what the failover route is for, usually forwarding to mobiles, so calls are not lost. Without it, a line fault means silence on the phone system.

How long does porting take?

It is set by the provider and outside our control. We state it as a separate item in the timeline rather than folding it into our own commitment.

Can we keep our provider?

Yes, provided they support SIP trunks. We work with the provider you already have; the proposal concerns configuration and sizing, not your commercial relationship.

Related services

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NEXT STEP

Size your lines correctly

We examine your real call traffic and propose channels, numbering and a failover route.

Request a site survey+30 210 598 9588

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