Delta-Multiplexing: A Novel Technique to Improve VoIP Bandwidth Utilization between VoIP Gateways

Gradually, Voice over Internet Protocol (VoIP) has been dominating the telecommunications world. Unfortunately, its applications are injecting a huge number of small packets in the network, which produces high overhead and therefore wastes network bandwidth. This paper proposed the use of a novel multiplexing technique, Delta-Multiplexing, to save the wasted bandwidth. In the Delta-Multiplexing technique, the VoIP packets destined to the same destination gateway are aggregated in a single UDP/IP header, therefore reducing the header overhead and saving network bandwidth. Moreover, the Delta-Multiplexing technique reduces the size of the packets payload by transmitting the difference between the consecutive packets payloads. Accordingly, the Delta-Multiplexing technique greatly saves bandwidth. We have simulated the Delta-Multiplexing technique using a 14-byte LPC codec. The result showed that Delta-Multiplexing is capable of saving between 68% and 72% as compared to conventional techniques (without multiplexing). Moreover, the Delta-Multiplexing technique reduces the number of VoIP packets running over the network, therefore reducing network traffic, overload, and congestion, thus improving the overall network performance.