Definition
Multicast is a network communication model that allows a single host to transmit the same data to multiple receivers simultaneously.
It saves network bandwidth and reduces loads by allowing efficient data transmission from the network center point to multiple points. Multicast enables easy support for value-added services such as live streaming, IPTV, remote education, telemedicine, online radio, and real-time video conferencing—applications that demand high bandwidth and real-time interaction.
Benefits
In point-to-multipoint communication scenarios, compared with unicast and broadcast transmission, multicast significantly reduces server load and improves bandwidth utilization.
Unicast Transmission:
In unicast transmission, a source sends an independent copy of data to each host requiring its data. In unicast mode, the amount of data transmitted on the network is proportional to the number of users that require the data. If a large number of users require the same data, the source host must send many copies of data to these users, consuming high bandwidth on the source and the network. As shown in Figure 1.
Figure 1: Unicast Transmission
From its transmission process, it can be seen that the unicast mode is not suitable for batch data transmission.
Broadcast Transmission:
In broadcast mode, data is sent to all hosts on a network segment regardless of whether they require the data. This threatens information security and causes storms on the network segment as hosts that do not need the information will also receive it. As shown in Figure 2.
Figure 2: Broadcast Transmission
From its transmission process, it can be seen that broadcast mode is not suitable for data transmission from a source to specified destinations, and it also wastes a great amount of bandwidth.
Multicast Transmission:
In multicast communication, the multicast source needs to send only one copy of data. A multicast distribution tree is then established using multicast routing protocols. During transmission, multicast gateways forward only one packet. It is replicated only at the gateways closest to the client, reducing server load and saving bandwidth. As shown in Figure 3.
Figure 3: Multicast Transmission
In summary, multicast has the following advantages:
• Compared with unicast, the multicast mode starts to copy and distribute data copies on the network node as far from the source as possible. Therefore, the amount of data and network resource consumption will not increase greatly when the number of receivers increases.
• Compared with broadcast, the multicast mode transmits data only to receivers that require the data. This avoids network resource waste and enhances data transmission security. In addition, broadcast operates only within a network segment, while multicast supports cross-network segment transmission.
Features and Advantages
Low Cost: Multicast is a cloud-native feature of eSurfing Cloud that allows you to quickly build multicast networks with minimal bandwidth usage. It reduces server load effectively and requires no additional physical devices or third-party software licenses.
You can deploy multicast networks rapidly, without the need for extra hardware or third-party certificates.
High Reliability: Supports distributed active-active clusters with horizontal scaling. It uses VXLAN for natural isolation and supports IGMPv2 and IGMPv3 dynamic multicast. This ensures precise packet forwarding and optimal replication, meeting the growing demands of your business.
Easy Maintenance: eSurfing Cloud provides a unified, visualized multicast network management interface that is simple to maintain and ready for immediate use.
Billing Instructions
Multicast follows a pay-as-you-go billing model, which includes connection fees and traffic processing fees. For details, see Multicast Billing Instructions.
Supported Regions
Supported only in certain availability zone (AZ) resource pools. Actual availability is subject to the console display.