Switching
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Topic: _________Switching , Circuit AND Packet Switching Submitted By:______ M.Dawood Khan Class: ______________________________BS ( I.T)4th R.No: __________________________ 021 Submitted to: _____________ Miss Saima Gul 0100090000037800000002001c00000000000400000003010800050000000b02 00000000050000000c02e401bd02040000002e0118001c000000fb02100007000 0000000bc02000000000102022253797374656d0001bd02000098c9110072edc6 30005d1a000c020000bd020000040000002d01000004000000020101001c0000 00fb02f0ff0000000000009001000000000440001254696d6573204e657720526f6 d616e0000000000000000000000000000000000040000002d010100050000000 902000000020d000000320a0e0000000100040000000000bc02e301201f070004 0000002d010000030000000000
What is Network Switching? A network switch is a small hardware device that joins multiple computers together within one local area network (LAN). Technically, network switches operate at layer two (Data Link Layer) of the OSI model. Network switches appear nearly identical to network hubs, but a switch generally contains more intelligence (and a slightly higher price tag) than a hub. Unlike hubs, network switches are capable of inspecting data packets as they are received, determining the source and destination device of each packet, and forwarding them appropriately. By delivering messages only to the connected device intended, a network switch conserves network bandwidth and offers generally better performance than a hub. As with hubs, Ethernet implementations of network switches are the most common. Mainstream Ethernet network switches support either 10/100 Mbps Fast Ethernet or Gigabit Ethernet (10/100/1000) standards. Different models of network switches support differing numbers of connected devices. Most consumer-grade network switches provide either four or eight connections for Ethernet devices. Switches can be connected to each other, a so-called daisy chaining method to add progressively larger number of devices to a LAN In a telecommunications network, a switch is a device that channels incoming data from any of multiple input ports to the specific output port that will take the data toward its intended destination. In the traditional circuit-switched telephone network, one or more switches are used to set up a dedicated though temporary connection or circuit for an exchange between two or more parties. On an Ethernet local area network (LAN), a switch determines from the physical device (Media Access Control or MAC) address in each incoming message frame which output port to forward it to and out of. In a wide area packet-switched network such as the Internet, a switch determines from the IP address in each packet which output port to use for the next part of its trip to the intended destination. In the Open Systems Interconnection (OSI) communications model, a switch performs the layer 2 or Data-Link layer function. That is, it simply looks at each packet or data unit and determines from a physical address (the "MAC address") which device a data unit is intended for and switches it out toward that device. However, in wide area networks such as the Internet, the destination address requires a look-up in a routing table by a device known as a router. Some newer switches also perform routing functions (layer 3 or the Network layer functions in OSI) and are sometimes called IP switches. On larger networks, the trip from one switch point to another in the network is called a hop. The time a switch takes to figure out where to forward a data unit is called its latency. The price paid for having the flexibility that switches provide in a network is this latency. Switches are found at the backbone and gateway levels of a network where one
network connects with another and at the subnetwork level where data is being forwarded close to its destination or origin. The former are often known as core switches and the latter as desktop switches. In the simplest networks, a switch is not required for messages that are sent and received within the network. For example, a local area network may be organized in a Token Ring or bus arrangement in which each possible destination inspects each message and reads any message with its address.
Different Models Of Switches
STES2908 8 Port Websmart Switch Description: The STES2908 is an 8-port 10/100Mbps Auto-Negotiation Web-Smart switch.It supports port mirroring and port bandwidth control. Administrator can monitors the real-time connectivity status of each port through its Web-based Interface. STES2908 supports Port VLAN of up to 9 groups and Port Trunking of up to 2 groups, QoS, Static MAC Address Table, port security, and broadcast storm control. It offers easy-to-use management Interface and it, fits smalland medium size enterprise, net cafe and smart residential areas network configurations.
STES2016 16 Port Websmart Switch Description: The STES2016 is a 16 port 10/100Mbps Auto-Negotiation Web-Smart switch. It supports port mirroring and port bandwidth control. Administrator can monitors the real-time connectivity status of each port through its Web-based Interface. STES2016 supports Port VLAN of up to 16 groups and Port Trunking of up to 2 groups, Quos, Static MAC Address Table, port security, and broadcast storm control. It offers easy-to-use management Interface and it, fits small and medium size enterprise, net cafe and smart residential areas network configurations.
STES2024 24 Port Websmart Switch Description: The STES2024 is a 24 port 10/100Mbps Auto-Negotiation Web-Smart switch.It supports port mirroring and port bandwidth control. Administrator can monitors the real-time connectivity status of each port through its Web-based Interface. STES2024 supports Port VLAN of up to 24 groups and Port Trunking of up to 2 groups, QoS, Static MAC Address Table, port security, and broadcast storm control. It offers easy-to-use management Interface and it, fits smalland medium size enterprise, net cafe and smart residential areas network configurations.
Packet Switching The concept of packet switching was first explored by Paul Baran in the early 1960s, and then independently a few years later by Donald Davies (Abbate, 2000). Packet switching is a network communications method that groups all transmitted data, irrespective of content, type, or structure into suitably-sized blocks, called packets. The network over which packets are transmitted is a shared network which routes each packet independently from all others and allocates transmission resources as needed. The principal goals of packet switching are to optimize utilization of available link capacity and to increase the robustness of communication. When traversing network adapters, switches and other network nodes, packets are buffered and queued, resulting in variable delay and throughput, depending on the traffic load in the network. Network resources are managed by statistical multiplexing or dynamic bandwidth allocation in which a physical communication channel is effectively divided into an arbitrary number of logical variable-bit-rate channels or data streams. Each logical stream consists of a sequence of packets, which normally are forwarded by a network node asynchronously using first-in, first-out buffering. Alternatively, the packets may be forwarded according to some scheduling discipline for fair queuing or for differentiated or guaranteed quality of service, such as pipeline forwarding or time-driven priority (TDP). Any buffering introduces varying latency and throughput in transmission. In case of a shared physical medium, the packets may be delivered according to some packetmode multiple access schemes. Packet switching contrasts with another principal networking paradigm, circuit switching, a method which sets up a specific circuit with a limited number dedicated connection of constant bit rate and constant delay between nodes for exclusive use during the communication session. Most data today is sent, using digital signals, over networks that use packet-switching. Using packet-switching, all network users can share the same paths at the same time and the particular route a data unit travels can be varied as conditions change. In packetswitching, a message is divided into packets, which are units of a certain number of bytes. The network addresses of the sender and of the destination are added to the packet. Each network point looks at the packet to see where to send it next. Packets in the same message may travel different routes and may not arrive in the same order that they were sent. At the destination, the packets in a message are collected and reassembled into the original message.
Packet switching is essentially connectionless, a packet switching network can be made connection-oriented by using a higher-level protocol. TCP, for example, makes IP
networks connection-oriented.
Two kinds of Packet Switching There are two basic types of Packet Switching. 1. Virtual Circuit Packet Switching Networks An initial setup phase is used to set up a route between the intermediate nodes for all the packets passed during the session between the two end nodes. In each intermediate node, an entry is registered in a table to indicate the route for the connection that has been set up. The packets passed through this route, have short headers, containing only a virtual circuit identifier (VCI). Each intermediate node passes the packets according to the information that was stored in its table, in the setup phase and according to the packets header content. In this way, packets arrive at the destination in the correct sequence. This approach is slower than Circuit Switching, since different virtual circuits may compete over the same resources. As in Circuit Switching, if an intermediate node fails, all virtual circuits that pass through it are lost. The most common forms of Virtual Circuit networks are ATM and Frame Relay, which are commonly used for public data networks (PDN). 2. Datagram Packet Switching Networks This approach uses a different, more dynamic scheme, to determine the route through the network links. Each packet is treated as an independent entity, and its header contains full information about the destination of the packet. The intermediate nodes examine the header of the packet, and decide the next hop of this packet. In the decision two factors are taken into account: The shortest way to pass the packet to its destination - protocols such as RIP/OSPF is used to determine the shortest path to the destination. Finding a free node to pass the packet to - in this way, bottle necks are eliminated, since packets can reach the destination in alternate routes.
Circuit Switching In this networking method, a connection called a circuit is set up between two devices, which is used for the whole communication. Information about the nature of the circuit is maintained by the network. The circuit may either be a fixed one that is always present, or it may be a circuit that is created on an as-needed basis. Even if many potential paths through intermediate devices may exist between the two devices communicating, only one will be used for any given dialog.
Example Of Circuit Switching Through Telephone Network.
Circuit-switching networks are sometimes called connection-oriented networks. In a circuit-switched network, before communication can occur between two devices, a circuit is established between them. This is shown as a thick blue line for the conduit of data from Device A to Device B, and a matching purple line from B back to A. Once set up, all communication between these devices takes place over this circuit, even though there are other possible ways that data could conceivably be passed over the network of devices between them.
Advantages of Circuit Switching: * Once the circuit has been set up, communication is fast and without error. * It is highly reliable Disadvantages: . * Involves a lot of overhead, during channel set up. * Waists a lot of bandwidth, especial in speech whereby a user is sometimes listening, and not talking. * Channel set up may take longer. To overcome the disadvantages of circuit switching, packet switching was introduced, and instead of dedicating a channel to only two parties for the duration of the call it routes packets individually as they are available. This mechanism is referred to as being connectionless
What is Network Switching? A network switch is a small hardware device that joins multiple computers together within one local area network (LAN). Technically, network switches operate at layer two (Data Link Layer) of the OSI model. Network switches appear nearly identical to network hubs, but a switch generally contains more intelligence (and a slightly higher price tag) than a hub. Unlike hubs, network switches are capable of inspecting data packets as they are received, determining the source and destination device of each packet, and forwarding them appropriately. By delivering messages only to the connected device intended, a network switch conserves network bandwidth and offers generally better performance than a hub. As with hubs, Ethernet implementations of network switches are the most common. Mainstream Ethernet network switches support either 10/100 Mbps Fast Ethernet or Gigabit Ethernet (10/100/1000) standards. Different models of network switches support differing numbers of connected devices. Most consumer-grade network switches provide either four or eight connections for Ethernet devices. Switches can be connected to each other, a so-called daisy chaining method to add progressively larger number of devices to a LAN In a telecommunications network, a switch is a device that channels incoming data from any of multiple input ports to the specific output port that will take the data toward its intended destination. In the traditional circuit-switched telephone network, one or more switches are used to set up a dedicated though temporary connection or circuit for an exchange between two or more parties. On an Ethernet local area network (LAN), a switch determines from the physical device (Media Access Control or MAC) address in each incoming message frame which output port to forward it to and out of. In a wide area packet-switched network such as the Internet, a switch determines from the IP address in each packet which output port to use for the next part of its trip to the intended destination. In the Open Systems Interconnection (OSI) communications model, a switch performs the layer 2 or Data-Link layer function. That is, it simply looks at each packet or data unit and determines from a physical address (the "MAC address") which device a data unit is intended for and switches it out toward that device. However, in wide area networks such as the Internet, the destination address requires a look-up in a routing table by a device known as a router. Some newer switches also perform routing functions (layer 3 or the Network layer functions in OSI) and are sometimes called IP switches. On larger networks, the trip from one switch point to another in the network is called a hop. The time a switch takes to figure out where to forward a data unit is called its latency. The price paid for having the flexibility that switches provide in a network is this latency. Switches are found at the backbone and gateway levels of a network where one
network connects with another and at the subnetwork level where data is being forwarded close to its destination or origin. The former are often known as core switches and the latter as desktop switches. In the simplest networks, a switch is not required for messages that are sent and received within the network. For example, a local area network may be organized in a Token Ring or bus arrangement in which each possible destination inspects each message and reads any message with its address.
Different Models Of Switches
STES2908 8 Port Websmart Switch Description: The STES2908 is an 8-port 10/100Mbps Auto-Negotiation Web-Smart switch.It supports port mirroring and port bandwidth control. Administrator can monitors the real-time connectivity status of each port through its Web-based Interface. STES2908 supports Port VLAN of up to 9 groups and Port Trunking of up to 2 groups, QoS, Static MAC Address Table, port security, and broadcast storm control. It offers easy-to-use management Interface and it, fits smalland medium size enterprise, net cafe and smart residential areas network configurations.
STES2016 16 Port Websmart Switch Description: The STES2016 is a 16 port 10/100Mbps Auto-Negotiation Web-Smart switch. It supports port mirroring and port bandwidth control. Administrator can monitors the real-time connectivity status of each port through its Web-based Interface. STES2016 supports Port VLAN of up to 16 groups and Port Trunking of up to 2 groups, Quos, Static MAC Address Table, port security, and broadcast storm control. It offers easy-to-use management Interface and it, fits small and medium size enterprise, net cafe and smart residential areas network configurations.
STES2024 24 Port Websmart Switch Description: The STES2024 is a 24 port 10/100Mbps Auto-Negotiation Web-Smart switch.It supports port mirroring and port bandwidth control. Administrator can monitors the real-time connectivity status of each port through its Web-based Interface. STES2024 supports Port VLAN of up to 24 groups and Port Trunking of up to 2 groups, QoS, Static MAC Address Table, port security, and broadcast storm control. It offers easy-to-use management Interface and it, fits smalland medium size enterprise, net cafe and smart residential areas network configurations.
Packet Switching The concept of packet switching was first explored by Paul Baran in the early 1960s, and then independently a few years later by Donald Davies (Abbate, 2000). Packet switching is a network communications method that groups all transmitted data, irrespective of content, type, or structure into suitably-sized blocks, called packets. The network over which packets are transmitted is a shared network which routes each packet independently from all others and allocates transmission resources as needed. The principal goals of packet switching are to optimize utilization of available link capacity and to increase the robustness of communication. When traversing network adapters, switches and other network nodes, packets are buffered and queued, resulting in variable delay and throughput, depending on the traffic load in the network. Network resources are managed by statistical multiplexing or dynamic bandwidth allocation in which a physical communication channel is effectively divided into an arbitrary number of logical variable-bit-rate channels or data streams. Each logical stream consists of a sequence of packets, which normally are forwarded by a network node asynchronously using first-in, first-out buffering. Alternatively, the packets may be forwarded according to some scheduling discipline for fair queuing or for differentiated or guaranteed quality of service, such as pipeline forwarding or time-driven priority (TDP). Any buffering introduces varying latency and throughput in transmission. In case of a shared physical medium, the packets may be delivered according to some packetmode multiple access schemes. Packet switching contrasts with another principal networking paradigm, circuit switching, a method which sets up a specific circuit with a limited number dedicated connection of constant bit rate and constant delay between nodes for exclusive use during the communication session. Most data today is sent, using digital signals, over networks that use packet-switching. Using packet-switching, all network users can share the same paths at the same time and the particular route a data unit travels can be varied as conditions change. In packetswitching, a message is divided into packets, which are units of a certain number of bytes. The network addresses of the sender and of the destination are added to the packet. Each network point looks at the packet to see where to send it next. Packets in the same message may travel different routes and may not arrive in the same order that they were sent. At the destination, the packets in a message are collected and reassembled into the original message.
Packet switching is essentially connectionless, a packet switching network can be made connection-oriented by using a higher-level protocol. TCP, for example, makes IP
networks connection-oriented.
Two kinds of Packet Switching There are two basic types of Packet Switching. 1. Virtual Circuit Packet Switching Networks An initial setup phase is used to set up a route between the intermediate nodes for all the packets passed during the session between the two end nodes. In each intermediate node, an entry is registered in a table to indicate the route for the connection that has been set up. The packets passed through this route, have short headers, containing only a virtual circuit identifier (VCI). Each intermediate node passes the packets according to the information that was stored in its table, in the setup phase and according to the packets header content. In this way, packets arrive at the destination in the correct sequence. This approach is slower than Circuit Switching, since different virtual circuits may compete over the same resources. As in Circuit Switching, if an intermediate node fails, all virtual circuits that pass through it are lost. The most common forms of Virtual Circuit networks are ATM and Frame Relay, which are commonly used for public data networks (PDN). 2. Datagram Packet Switching Networks This approach uses a different, more dynamic scheme, to determine the route through the network links. Each packet is treated as an independent entity, and its header contains full information about the destination of the packet. The intermediate nodes examine the header of the packet, and decide the next hop of this packet. In the decision two factors are taken into account: The shortest way to pass the packet to its destination - protocols such as RIP/OSPF is used to determine the shortest path to the destination. Finding a free node to pass the packet to - in this way, bottle necks are eliminated, since packets can reach the destination in alternate routes.
Circuit Switching In this networking method, a connection called a circuit is set up between two devices, which is used for the whole communication. Information about the nature of the circuit is maintained by the network. The circuit may either be a fixed one that is always present, or it may be a circuit that is created on an as-needed basis. Even if many potential paths through intermediate devices may exist between the two devices communicating, only one will be used for any given dialog.
Example Of Circuit Switching Through Telephone Network.
Circuit-switching networks are sometimes called connection-oriented networks. In a circuit-switched network, before communication can occur between two devices, a circuit is established between them. This is shown as a thick blue line for the conduit of data from Device A to Device B, and a matching purple line from B back to A. Once set up, all communication between these devices takes place over this circuit, even though there are other possible ways that data could conceivably be passed over the network of devices between them.
Advantages of Circuit Switching: * Once the circuit has been set up, communication is fast and without error. * It is highly reliable Disadvantages: . * Involves a lot of overhead, during channel set up. * Waists a lot of bandwidth, especial in speech whereby a user is sometimes listening, and not talking. * Channel set up may take longer. To overcome the disadvantages of circuit switching, packet switching was introduced, and instead of dedicating a channel to only two parties for the duration of the call it routes packets individually as they are available. This mechanism is referred to as being connectionless
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