A Comparison Research on DSCP Marking’s Impact to the QoS of VoIP-based and SS7-based Phone Calls

Voice over Internet Protocol (VoIP) phone service has several factors that can contribute to its degraded quality. Some of these factors include delay, packet loss, and jitter. This research study focuses on VoIP phone services offered to customers by cable companies that utilize broadband hybrid fiber coaxial (HFC) networks. The value of this research comes from the nature of the HFC broadband networks where they deliver three types of traffic on the same network links. Traffic types include voice, data, and video. Voice is unlike data and video, some delays or packet loss can result in a noticeable degraded impact on a VoIP's phone conversations. This research will analyze and assess VoIP traffic prioritization and its impact on VoIP's quality of service (QoS) based on the concept of differentiated services code point (DSCP) markings. This study examines two call types that include VoIP-based and signaling system 7 (SS7) based networks. This research mimics the production environment. This study provides some DSCP markings configurations that can clearly improve VoIP's conversations quality.