HUB and switch
1. From the perspective of OSI architecture, HUB belongs to the first layer physical layer equipment of OSI, while switch belongs to the second layer data link layer equipment of OSI. This means that HUB only plays the role of synchronization, amplification and shaping for data transmission, and cannot effectively deal with short frames and fragments in data transmission, and cannot guarantee the integrity and correctness of data transmission. The switch can not only synchronize, amplify and shape data transmission, but also filter short frames and fragments.
2. From the working mode, HUB is a broadcast mode, that is to say, when one port of HUB is working, all other ports listen to the information, which is easy to cause a broadcast storm. When the network is large, the network performance will be greatly affected, so what can be done to avoid this phenomenon? Switches can play this role. When the switch works, only the request port and the destination port respond to each other.
Ring other ports, the switch can isolate the collision domain and effectively suppress the broadcast storm.
3. In terms of bandwidth, no matter how many ports there are in the hub, all ports * * * enjoy a bandwidth, only two ports can transmit data at the same time, and other ports can only wait; At the same time, the hub can only work in half-duplex mode. For the switch, each port has its own bandwidth, and when two ports work, it will not affect the work of other ports. At the same time, the switch can work in half-duplex mode and full-duplex mode.
It can be seen that all ports on the hub are competing for the bandwidth of a shared channel, so with the increase of network nodes, the data transmission volume increases and the available bandwidth of each node decreases. HUB transmits data in the form of broadcast, which means transmitting data to all ports.
All ports of the switch have dedicated channel bandwidth to ensure fast and efficient data transmission on each port. Switches provide exclusive point-to-point connections for users, and packets are only sent to the destination port, not all ports.
But the price of switches is generally higher than that of hubs.