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Switch works

Exchange, LAN switches (switching) is based on both ends of the communication transmission information need, complete with the manual or automatic way, to transfer information technology to meet the requirements of the appropriate routing of them collectively. Broad switches (switch) is a communication system for information exchange-enabled devices.
in computer network systems, Exchange concept is the shared pattern of improvement. Previously introduced HUB hub is a shared device, HUB itself cannot identify destination addresses, hosts when a host on the same LAN to b when data is transferred, packets from the HUB system is based on a network of broadcast transmissions, by each terminal by verifying the header address information to determine whether to accept. In other words, in this mode, at the same time only one set of data frames on the network communication, if a collision had to try again. Network bandwidth is shared in this way.
switch back has a very high bandwidth bus and internal switching matrix. Switch of all of port are hanging received in this article back bus Shang, control circuit received data package yihou, processing port will find memory in the of address table to determine purpose MAC (NIC of hardware address) of NIC (NIC) hanging received in which port Shang, through internal Exchange matrix quickly will data package transfer to purpose port, purpose MAC if not exists only broadcast to all of port, received port response Hou switch will "learning" new of address, and put it added into internal MAC address table in the.
using the switch or network "fragment", by against the MAC address table, switches allow only the necessary network traffic through the switch. Filtered and forwarded through the switch, can effectively isolate broadcast storms and reduce the appearance of packet error and wrong, to avoid a sharing violation.
switch between multiple ports at the same time for data transmission. Each port can be regarded as a separate network segment connected whole bandwidth, network equipment on its own without having to compete with other devices using the. When node a sends data to node d, node b sends data to node c, and two transports are entitled to the full bandwidth of the network, all have their own virtual connections. If here are using 10Mbps Ethernet switches, the switches when the total circulation is equal to 2x10Mbps=20Mbps, and when you use the shared 10Mbps HUB, a HUB of the total flow volume will not exceed 10Mbps.
in short, is based on the MAC address of the switch identification, network equipment forward packets to complete the package. Switches can "learn" MAC address, and put them in the internal address tables, through the sending of data frames and set up temporary switching path between the target receiver, make a data frame directly from the source address to the destination address.
switches are divided into two types: Wan and LAN switches. Wide-area network switches are mainly used in the field of telecommunications, provide communication platforms. LAN switch is used in local area networks, used to connect devices, such as PC and network printers, and so on. From a transmission medium and transfer speeds can be divided into the Ethernet switch, fast Ethernet switches, Gigabit Ethernet, FDDI switches, ATM switch and token ring switches. From the scale used can be divided into enterprise-class switches, departmental and workgroup switches, level switches. Division of the manufacturers are not entirely consistent. In General, enterprise class switches are rack-mountable and departmental class switches can be rack-mounted (less number of slots), or it can be fixed-configuration, and workgroup switch is a fixed profile (more simple).
on the other hand, from the scope of application, while acting as a backbone switch, switch to support large enterprise above the 500 information applications for enterprise-class switches, supports 300 points the following Midsize Enterprise switches for departmental class switches, supports 100 switches for workgroup switch information points.
, network switch function switch key features include physical addressing, network topology and flow control, error checking, frame sequence. Current switches also has some new features, such as a VLAN (virtual local area network) support, support for link aggregation, and some even have a firewall feature.
: Ethernet switches connected to each port device's MAC address, and address with the appropriate port mappings stored in the switch MAC address cache table.
forwarding/filtering: when a data frame in the destination address in the MAC address table mapping, it is forwarded to the connecting port, but not all, of the destination node port (such as the data for broadcast/multicast frames are forwarded to all ports).
elimination circuit: when switch includes a redundant circuits, Ethernet switch with spanning tree Protocol to prevent loops, while backup path is permitted.
switch but can connect to the same type of network, it can also be in different types of networks (such as Ethernet and fast Ethernet network) interconnection between roles. Many switches today are able to provide support for fast Ethernet or FDDI, the high-speed connection ports, use to connect other network switches or for bandwidth critical servers provide additional bandwidth.
in General, each port of the switch is used to connect a separate network segment, but sometimes in order to provide faster access speed can be important on a network computer is connected directly to the switch ports. In this way, network key server and important users faster access speeds, supporting greater flow of information.