Issue link: https://www.e-digitaleditions.com/i/1255991
For networks that run AVoIP services in conjunction with other types of data, it is highly advised to prioritize AVoIP- related protocols (i.e., multicast and IGMP) over non-delay critical data. 12 I ICT TODAY 192.168.11.114 192.168.11.117 192.168.11.118 192.168.11.121 192.168.11.116 192.168.11.115 FIGURE 5: Illustration of multicast transmission. ally to each receiver, consequently reducing the load on the network and encoder devices (Figure 5). Traffic Management Most data flowing over the LAN and wide area network (WAN) connections, where the internet resides, use con- nection-oriented protocol layers. Packets sent have sequence numbers, and there is an acknowledgment mechanism in place that ensures packets are retransmitted if there is acknowledgement of no receipt on the receiver end. Thus, standard internet traffic, such as email or web browsing, will generally continue unabated even when quality issues (e.g., packet arrival order, packet loss) arise. If a packet does not arrive, the user device—with the help of buffering algorithms, acknowledgements, and retransmissions—can still receive the entire data. These retransmissions and acknowledgments sound like mecha- nisms that are applicable for every type of data traffic. The catch is that latency and delay make these approaches to data transmission ineffective for real-time video and AVoIP. Low-latency, high-fidelity AVoIP networks are "connectionless," meaning that there is no feedback coming from the receiving end to indicate packet loss. This makes lower latency streaming over the network Multicast—A multicast is described as a single transmission host to a group of receiving hosts. In this transport method, receiving hosts subscribe to a multicast group, and any receivers subscribed to that group receive the information forwarded to that multicast group address. The protocol that is used by receivers to subscribe to the multicast group is called internet group management protocol (IGMP). Audiovisual over IP relies on multicast functionality to transmit and receive video and audio. Multicast pro- vides efficiency, which is very important when moving high bit rate video over IP networks. Multicast eliminates the need to send the same high bit rate stream individu-