Promax -27 Manual De Uso página 114

The protocol DOCSIS / EuroDOCSIS uses the concept of service flows for traffic
transmitted between cable modem and CMTS. A service flow is a one-way packets flow
that provide a specific service quality. Traffic is classified in a service flow, and each
service flow has its own set of parameters, named QoS.
QoS (Quality of Service) are technologies that ensure the transfer of certain
amount of data at a time, ensuring a good quality of service.
There are four types of QoS defined, depending on the type of data to transmit:
UGS (Unsolicited Grant Service), rtPS (real time Polling Service), nrtPS (non real time
Polling Service) and BE (Best Effort).
In the case of VoIP, voice over IP, the type UGS is the most suitable, because it
is designed for applications that generate fixed-size packets on a periodic basis. In this
type, CMTS provides a fixed-size grant to a service flow at fixed intervals without
additional polling or interaction.
The PROMAX-27 allows the user to establish a service flow to verify the quality of
service based on type UGS type. Flow services are used to verify the network between
the test point and the CMTS. It analyses parameters that can affect the quality of
communication, among them latency, jitter, lost packets, MOS and R-value.
In short, the VoIP function of the PROMAX-27, performs an exhaustive analysis
of the network based on parameters set by UGS, which will ensure the best quality
service.
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USER'S MANUAL. PROMAX-27
09/2010