Triple-Play Service Deployment

Chapter 8: Troubleshooting VoIP
Objective voice quality is established by generating a MOS, which
is then compared to maintenance and provisioning and SLA
requirements. Measurements are taken at the packet interface of
live calls. The MOS is calculated based on network performance
and transport measurements such as packet delay, packet jitter,
packet loss, and out-of-sequence packets. The customer quality
complaint is based on an actual MOS score derived through the
customer’s ear. The technician’s MOS values are based on a MOS
score calculated by a test device. If the test set shows a good MOS
score, the call must be captured and listened to. To take this step,
the technician must use a test set with the ability to play back the
voice and emulate the actual VoIP phone.
VoIP Testing Strategy
Providers rolling out VoIP in the triple play must address a tough
challenge from the beginning. Potential customers have a
preconceived expectation of the quality of VoIP services. These
expectations are based on years of experience with legacy landline
voice services. Achieving this level of service and voice quality is
possible for hosted residential and business VoIP services with
careful testing at all phases of service deployment. For a service
provider, making a bad first impression with a new service, which
often involves losing the customer, is usually more expensive
implementing proactive and comprehensive test procedures.
Experience gained from the deployment of other new services
demonstrates the importance of sound installation methods and
procedures supported by effective field test tools in achieving
deployment success. This combination can enable the field
technician to turn-up new services and to troubleshoot problems
quickly yet efficiently. In this model, deployment costs are
minimized by enabling less experienced technicians to isolate and
solve problems at the premises. Providers will see the impact on
the bottom line—future trouble calls, trouble escalation, and
dispatch of higher level support can all be greatly reduced.
219