STANDARD Revision 1.0
C4® CMTS Release 8.3 User Guide
© 2016 ARRIS Enterprises LLC. All Rights Reserved.
810
Chapter 28
PacketCable™ Services and Voice Applications
PacketCable Overview ...................................................................... 810
PacketCable Multimedia Overview .................................................. 813
PacketCable Overview
PacketCable Voice-only refers to the functionality defined by the following CableLabs specifications:
PacketCable 1.0
PacketCable 1.1
PacketCable 1.5
PacketCable 2.0 is addressed later in this chapter.
Packetized voice traffic, such as that carried over an IP network, tends to have stringent latency and jitter requirements. If
one adjusts for the packet arrival jitter through the use of a large jitter buffer, the latency of the audio hampers a normal
conversation pattern. If the jitter buffer is too small, poor audio quality results as the audio codec hardware under- or
overflows due to packets arriving too late or too early. In order to reduce both jitter and latency simultaneously in a
network that has not been over-engineered, the packets must be treated with an enhanced quality-of-service (QoS).
PacketCable services on the C4/c CMTS provide the ability to place enhanced-QoS telephone calls over an existing DOCSIS
cable data access network. To provide this capability, the C4/c CMTS must communicate with several other specialized
servers over a managed IP network that is capable of providing enhanced QoS from end-to-end. See the figure on see
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PacketCable Multimedia Overview
(page 813). These other servers may be packaged separately or they may be bundled
