Role of network layer and Internet Multicast

The role of network layer and Internet multicast 1. Briefly describe the role of the OSI physical layer, data link layer, and network layer? Network Layer: provides the most suitable path for packets or groups through the Communication Subnet through the routing selection protocol (Routing Algorithm). Data Link Layer: various control protocols are used to convert erroneous physical channels into error-free data frames that can be reliably transmitted. Physical Layer: uses transmission media to provide channels for transmission of data frames, enabling transparent transmission of bit streams. 2. What are the benefits of Internet multicast? Multicast is a network technology that allows one or more senders to send a single packet to multiple receivers. Multicast can greatly save network bandwidth, because no matter how many destination addresses there are, only a single packet is transmitted on any link of the network, therefore, the core of multicast technology is to ensure service quality on the premise of Saving network resources. The multicast protocol includes the IGMP at the network layer and IGMP Snooping at the link layer.