Abbey, the UK's sixth largest bank, has embarked on a project to boost sound quality on the Voice over IP (VoIP) network that it is rolling out across 800 of its UK branches.

The project centres on embedding a voice quality monitoring system into the bank's BT VoIP network.

The software, from BT spin-off monitoring firm Psytechnics, will catch, diagnose and repair "potentially customer-affecting faults".

Psytechnics will monitor areas such as jitter and packet loss to help assess and maintain voice quality.

The monitoring software will be able to detect problems relating to common VoIP quality issues, such as buffer size, and notify BT before the fault causes noticeably poor voice quality.

The deal will see Psytechnics provide BT with weekly and monthly voice quality assessments, based on the International Telecommunications Union's mean option score (MOS) for measuring VoIP voice quality.

These MOS grades assess voice quality on VoIP networks from one to five, with five indicating the highest quality available.

Psytechnic said its network management software, which incorporates MOS standards, will help BT to ensure that it always delivers an MOS voice quality level of at least 3.7.

"In the early days we had individual engineering problems," said Nigel Chisnall, IT architect at Abbey. "MOS is the ultimate service level agreement."

"With voice quality guarantees in place, the VoIP network will allow us to improve both internal and customer-facing communications, and to increase flexibility to meet future business needs."

Psytechnics chief executive John Winchester added: "Employing MOS metrics to monitor voice quality is not only an essential part of network management of VoIP systems, it is a meaningful service level agreement term that helps to ease concerns associated with implementing a new technology."