Development and Validation of VoIP features in PacketCable Technology

Abstract

PacketCable is a CableLabs speci cations in e ort to design and support con- vergence of voice, video and other IP based applications over the existing cable networks. PacketCable 2.0, the latest version of the PacketCable is based on the IP Multimedia Services developed by the 3rd Generation Partnership Protocol. Packet- Cable 2.0 is a SIP based architecture for providing IP multimedia services. Present work is focused on providing analog telephony features on the managed IP network. SLIC-SLAC chip has been interfaced with the Set Top Box to avail with the basic analog telephony functions which are provided by the PSTN. An individual hard- ware component as Cable Modem is provided with the set top box to obtain the IP connectivity. Connection between user and service provider secure between the user and service provider by means of provisioning of the User Equipment. Compression of voice frames with the help of the CODEC available and converting them in the RTP packets will help in transmission on the IP network. Controlling of packets

ow between the sender and the receiver is done with the help of the Real Time Control Protocol (RTCP). Extended report of RTCP which contains the di erent parameters related to source and destination. These parameters can be used for di erent purposes which are helpful in improving the voice quality. Voice quality in the PacketCable can be a ected by signal level, echo, delay, codec and other packet impediments. E ect of this parameter and their possible solutions are discussed. Measuring delay for the di erent case is also shown. Jitter bu er which is used at the receiver side to compensate for the jitter. Adaptive Jitter Bu er which is used in the PacketCable has the range of 20-420msec theoretically. Adaptive jitter bu er with its mechanism of how the jitter will be controlled for the PacketCable has been explained in detail. Algorithm to calculate the packet loss and packet discard is also discussed. Adaptive Jitter Bu er used in the PacketCable behaves according to the theoretical limit. PacketCable in all is the new technology developed and validated for the new era of communication.