Ethernet Communications and Switch port configuration - networks 802.3/Ethernet
Ethernet Communications
Communications in a switched LAN network occur in three ways: unicast, broadcast and multicast:
Unicast: Communication in which a host sends a frame to a specific destination. In the unicast transmission, there are only a transmitter and a receiver. Unicast transmission is the predominant mode of transmission in the LAN and the Internet. Some examples of protocols that use unicast transmissions are: HTTP, SMTP, FTP and Telnet.
Broadcast: Communication in which a frame is sent from an address to all other directions. In this case, there is only one source but the information is sent to all connected receivers. The broadcast transmission is essential when sending the same message to all devices on the LAN. An example of broadcast transmission is the address resolution query sent by the Address Resolution Protocol (ARP) to all computers on a LAN.
Multicast: Communication in which it sends a frame to a specific group of devices or clients. The multicast transmission customers must be members of a logical multicast group to receive the information. An example of multicast transmission is voice and video related to business meetings in web-based conference.
Duplex Settings
There are two types of parameters for duplex communications in an Ethernet network: half duplex and full duplex.
Half Duplex: half-duplex communication is based on a unidirectional data flow in the sending and receiving data do not occur simultaneously. This is similar to the role of two-way radios or two walkie-talkies where only one person can talk at once. Half-duplex communication implements the CSMA / CD in order to reduce the chances of collisions and detect them if they arise.
Half-duplex communications malfunctions occur due to the constant expected, since the flow of data occurs only in one direction at a time. Half-duplex connections are often the oldest hardware devices such as hubs.
Full duplex: In full-duplex communications, data flow is bidirectional, so the information can be sent and received simultaneously. The bidirectional capacity improves performance, because it reduces the wait time between transmissions. In full-duplex mode, the collision detection circuit is disabled. The frames sent by the two end nodes connected can not collide because they use two separate circuits on the cable network.
Switch port configuration
The switch port must be configured with a duplex settings match the type of medium.
The auto option sets the duplex mode autonegotiation. When this mode is enabled, both ports are communicated to decide the best mode of operation.
The full option sets the full-duplex mode.
The half option sets the half-duplex mode.
For Fast Ethernet and 10/100/1000 ports, the default is auto. For 100BASE-FX ports, the default is full. The 10/100/1000 ports operate in both half-duplex mode and in full-duplex when set to 10 or 100 Mb / s, but they work in full-duplex mode when set to 1000 Mb / s.
MAC address and MAC address tables of the switches
The switches use MAC addresses for routing the communications network through the port structure corresponding to the destination node. The structure of the switch are integrated circuits and attached machine programming that lets you control the data paths through the switch. The switch must first know which nodes exist in each of its ports to define what the port used to transmit a unicast frame.
The switch determines how to handle incoming data frames by a MAC address table. The switch generates its MAC address table recording MAC addresses of the nodes that are connected in each of its ports. Once the MAC address of a specific node in a given port is registered in the address table, the switch knows to send traffic destined to that specific node from the port assigned to that node for subsequent transmissions.
Methods of the switch packet forwarding
This topic will describe how switches forward Ethernet frames across a network. The switches can work in different modes and they can have both positive or negative.
Previously, the switches used to use one of the following methods to switch data forwarding between the ports of the network: switching method of cutting or storage and shipping. Button switch forwarding method shows these two methods. However, store and forward is the only forwarding method used in current models of Cisco Catalyst switches.
Store and forward switching
In this type of switching, when the switch receives the frame, this is stored in data buffers to receive the frame in its entirety. During storage, the switch analyzes the frame to find information about your destination. In this process, the switch also performs error checking using the trailer portion of the Cyclic Redundancy Check (CRC) of the Ethernet frame.
Communications in a switched LAN network occur in three ways: unicast, broadcast and multicast:
Unicast: Communication in which a host sends a frame to a specific destination. In the unicast transmission, there are only a transmitter and a receiver. Unicast transmission is the predominant mode of transmission in the LAN and the Internet. Some examples of protocols that use unicast transmissions are: HTTP, SMTP, FTP and Telnet.
Broadcast: Communication in which a frame is sent from an address to all other directions. In this case, there is only one source but the information is sent to all connected receivers. The broadcast transmission is essential when sending the same message to all devices on the LAN. An example of broadcast transmission is the address resolution query sent by the Address Resolution Protocol (ARP) to all computers on a LAN.
Multicast: Communication in which it sends a frame to a specific group of devices or clients. The multicast transmission customers must be members of a logical multicast group to receive the information. An example of multicast transmission is voice and video related to business meetings in web-based conference.
Duplex Settings
There are two types of parameters for duplex communications in an Ethernet network: half duplex and full duplex.
Half Duplex: half-duplex communication is based on a unidirectional data flow in the sending and receiving data do not occur simultaneously. This is similar to the role of two-way radios or two walkie-talkies where only one person can talk at once. Half-duplex communication implements the CSMA / CD in order to reduce the chances of collisions and detect them if they arise.
Half-duplex communications malfunctions occur due to the constant expected, since the flow of data occurs only in one direction at a time. Half-duplex connections are often the oldest hardware devices such as hubs.
Full duplex: In full-duplex communications, data flow is bidirectional, so the information can be sent and received simultaneously. The bidirectional capacity improves performance, because it reduces the wait time between transmissions. In full-duplex mode, the collision detection circuit is disabled. The frames sent by the two end nodes connected can not collide because they use two separate circuits on the cable network.
Switch port configuration
The switch port must be configured with a duplex settings match the type of medium.
The auto option sets the duplex mode autonegotiation. When this mode is enabled, both ports are communicated to decide the best mode of operation.
The full option sets the full-duplex mode.
The half option sets the half-duplex mode.
For Fast Ethernet and 10/100/1000 ports, the default is auto. For 100BASE-FX ports, the default is full. The 10/100/1000 ports operate in both half-duplex mode and in full-duplex when set to 10 or 100 Mb / s, but they work in full-duplex mode when set to 1000 Mb / s.
MAC address and MAC address tables of the switches
The switches use MAC addresses for routing the communications network through the port structure corresponding to the destination node. The structure of the switch are integrated circuits and attached machine programming that lets you control the data paths through the switch. The switch must first know which nodes exist in each of its ports to define what the port used to transmit a unicast frame.
The switch determines how to handle incoming data frames by a MAC address table. The switch generates its MAC address table recording MAC addresses of the nodes that are connected in each of its ports. Once the MAC address of a specific node in a given port is registered in the address table, the switch knows to send traffic destined to that specific node from the port assigned to that node for subsequent transmissions.
Methods of the switch packet forwarding
This topic will describe how switches forward Ethernet frames across a network. The switches can work in different modes and they can have both positive or negative.
Previously, the switches used to use one of the following methods to switch data forwarding between the ports of the network: switching method of cutting or storage and shipping. Button switch forwarding method shows these two methods. However, store and forward is the only forwarding method used in current models of Cisco Catalyst switches.
Store and forward switching
In this type of switching, when the switch receives the frame, this is stored in data buffers to receive the frame in its entirety. During storage, the switch analyzes the frame to find information about your destination. In this process, the switch also performs error checking using the trailer portion of the Cyclic Redundancy Check (CRC) of the Ethernet frame.
0 Comments:
Post a Comment