Paul Colmer & Associates — open-source PBX and VoIP consultancy in Johannesburg
Paul Colmer & Associates is a Johannesburg communications and IT consultancy built around open-source voice. It designs and supports unified communications on Linux, Asterisk and Ubuntu, terminating over SIP and IAX, and states plainly that it does not endorse proprietary equipment or software. Alongside the technical work it runs specialised recruitment in the IT and telecommunications sectors, which is an unusual pairing in this directory.
Key facts
| Who they are | A communications and IT consultancy specialising in local and cloud-based unified communications, describing custom-built solutions rather than packaged products |
| Open-source position | Explicit and deliberate. The company states it supports Linux, Asterisk, Ubuntu and the open-source initiative, and that it does not endorse proprietary systems because they lock clients into product cycles and licence fees. Few suppliers in this directory take a position that clear |
| Voice services | Carrier-grade voice via next-generation telecoms providers, with cloud-based communication converged and terminating over SIP and IAX. IAX support is genuinely uncommon and points to real Asterisk depth |
| Full service list | Specialised consulting, unified communications, VoIP, network design covering LAN, VPN, WAN and WLAN, peripheral IT support, smartphone apps, training and web design |
| Recruitment | The practice also runs specialised recruitment within the IT and telecommunications sectors. If you are struggling to hire an Asterisk engineer, that is a relevant second service from the same people |
| Network design | LAN, VPN, WAN and WLAN design with full monitoring, and training for your own IT staff. The stated design priorities are performance, reliability and security |
| Head office | 31 John Voster Road, Rand Park Ridge, Johannesburg |
| Customer rating | No rating is shown. The company’s Google listing matches its domain and published phone number but carries no reviews, so there is nothing to publish |
| Pricing | Project-based and not published. Consultancy of this kind is scoped rather than priced off a list, so expect a proposal against a defined brief |
| Founded | Not publicly stated |
| ICASA licence | Not publicly stated. As a consultancy it designs and implements systems rather than carrying calls itself, so the licensing question belongs to whichever provider terminates your traffic |
| Listed In | Cloud PBX Providers |
Buying expertise rather than a subscription
Almost every other listing in this category sells you a monthly service. This one sells you a design and an implementation, and the difference is worth understanding before making contact. An open-source PBX built on Asterisk is yours: you own the configuration, you are not paying per extension forever, and nobody can raise a licence fee on you. The cost is that somebody has to look after it, either your own staff or a consultancy on a support agreement, and that is a genuine ongoing obligation rather than a footnote. Ask directly what support looks like after go-live, what it costs, and what happens if the consultancy is unavailable when something breaks at nine on a Monday. The technical signals here are credible. IAX alongside SIP is not something a generalist mentions, and offering training for your own IT staff suggests a willingness to make you independent rather than dependent, which is consistent with the stated open-source position. The recruitment arm is an unusual and practical extra: an Asterisk skills gap is exactly what makes businesses abandon self-hosted voice, and a supplier who can also help you hire for it addresses the real risk. Weigh this against a hosted provider on total cost across three to five years rather than on the monthly figure alone. Compare providers in the cloud PBX directory.
Who Paul Colmer & Associates is a fit for
- Businesses that want to own an Asterisk or Linux-based PBX outright rather than rent one
- Organisations avoiding proprietary licence cycles and per-extension subscription pricing
- Companies with in-house IT who want the system designed, then training to run it themselves
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Ask what happens after go-live: who supports the system, at what cost, and what the escalation path is if the consultancy is unavailable. Get the project scoped as a fixed brief with a written handover, including configuration documentation. Compare the total cost over three to five years against a hosted per-extension service rather than judging on the implementation fee alone.
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What does Paul Colmer & Associates do?
Consulting, unified communications and VoIP design on open-source platforms, plus network design, IT support, smartphone apps, training, web design and specialised IT and telecoms recruitment.
Which platforms do they work on?
Linux, Asterisk and Ubuntu, with voice terminating over SIP and IAX. The company states it does not endorse proprietary equipment or software.
Why choose an open-source PBX?
You own the configuration and avoid per-extension licence fees and vendor product cycles. The trade-off is that somebody has to maintain it, so establish the support arrangement before you commit.
Where are they based?
31 John Voster Road, Rand Park Ridge, Johannesburg.
What does it cost?
Engagements are project-based and not published. Expect a proposal against a defined brief rather than a monthly per-user price.
Do they help with hiring?
Yes. The practice runs specialised recruitment within the IT and telecommunications sectors, which is relevant if the skills to run a self-hosted PBX are the constraint.
This listing is maintained by WhichVoIP, an independent South African telecoms comparison service running since 2019. Details are verified against the provider’s public website and were last reviewed on 31 July 2026.