Triple-Play Service Deployment

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Chapter 2: Triple-Play Service Delivery over Ethernet Networks
For video quality measurements, additional important metrics
may include the measurement of the PCR jitter in the Ethernet
aggregation network, as these may be caused by the content
quality problems (at the super head end) or overall network
packet jitter. The source of the problem can be differentiated by
evaluating more than one channel/program at a time. If excessive
PCR jitter is present at more than one channel, the overall network
jitter is most likely at fault. If excessive PCR jitter is present on only
one channel, then a video source problem (at a super headend) is
typically the cause.
Voice over IP
(Note: VoIP deployment and testing is described in detail in Chapter 8.)
Successful voice over IP (VoIP) service delivery over a convergent
network can be facilitated by an understanding of the service
characteristics and quality metrics that are affected by events in
the Ethernet aggregation network. Furthermore, it is important to
state that Ethernet and IP layers are critical to the deployment and
troubleshooting of VoIP service, and have significant impact on
the overall QoE parameters, including dropped calls and call
quality. Items that affect the overall transport quality of VoIP
service are IP packet delay, loss, jitter, and out of sequence (OoS)
packets. While these are described in more detail in Chapter 8,
their impact is briefly summarized below.
– Packet delays can have varying effects on voice quality, so it is
important to measure the delay at the time of service installation
to provide a benchmark for verification against potential
problems.
– Packet loss can occur for a variety of reasons inside a network.
Periodic losses in excess of 5 to 10 percent of all voice packets
transmitted will degrade voice quality significantly.