World Telecom Labs (WTL) has announced that more than six billion calls lasting around ten billion (ten thousand million) minutes have now passed through its specialist VoIP switches deployed by five of Nigeria's interconnect exchange carriers.

According to a statement issued by WTL, five carriers - Breeze Micro, Exchange, ICN, Niconnx and Solid – have built new VoIP networks across Nigeria with local switching enabled at new POPs in Abuja, Lagos, Port Harcourt, Ibadan and Kano.

WTL added that the carriers chose to build VoIP networks rather than legacy TDM as it was both quicker and cheaper – "and, with the use of WTL's advanced compression techniques, more calls can be transmitted down the links."

"The VoIP networks have significantly improved the quality of voice calls in Nigeria by increasing capacity and taking traffic of congested long-distance inter-city links," read the statement by WTL.

Based on figures sourced from the Nigerian Communications Commission (NCC), since the end of 2013, when the new carriers went live, there has been a 70% reduction in call failure, a 50% decrease in dropped calls, 30% reduction in traffic congestion, and a 60% reduction in signalling congestion.

Breeze Micro is headquartered in Kano and works with Nigeria's operators to transport voice traffic across Northern Nigeria.

Jihad Jaafar, CTO of Breeze Micro, said "The interconnect exchange carriers were wise to choose VoIP and even wiser to choose WTL whose continued support has been instrumental in improving voice calls in Nigeria."

WTL has been working with operators in Nigeria since 2010 helping them to maximise TDM voice capacity and then migrate to VoIP.

Leigh Smith, MD of WTL, said, "Many people have said that we accelerated the update of VoIP in Nigeria as we made it very easy for the new carriers to build, manage and expand their VoIP networks. Nigeria has provided the rest of Africa with a blueprint for how they can decrease congestion on traditional voice networks."