Asynchronous Transfer Mode Overviews

ATM Model

Asynchronous Transfer Mode: ATM network communications. A protocol name is the same as standard ATM data transmission speed by ATM has been developed for use with the look. Multiple data formats and require high-speed data transmission more. A data transmission speed from 2 Mbps to a Gbps network media in a call from Finance Co. yoke. Fiber cable coat. Or double cross lines (Twisted pair) has been developed by the ATM network packet switch (packet switched), which will share information to send out a small unit. Called a packet (packet) and a small constant then each packet sent out. Then bring together the information of the original destination to another advantage of ATM is to use a variety of information such as animation, computer data or audio more efficiently. A high speed data. And also guarantee the quality of delivery because of Quality of Service (QoS).

Features of ATM networks over other network types are high data rate transmission. And travel time of less information. Resulting in some groups believe that the core technology of the ATM network supporting LAN in the future due to the Application for example, higher data rate transmitted over the conference call. (Videoconferencing) or even a reply to the Client Application to Sever.

ATM network is a packet switch specialties. With the information you send a packet switch is generally called a “packet”, but will use ATM “cell” instead of using the word because cells. Cells that are small size and constant While the packet size is not fixed. And larger cells. The cell is then the standard size is 53 bytes by 48 bytes and data bytes are 5 headers (Header) of the ATM switch makes work faster than other switch of the network.

To avoid loss of data using ATM switch will adapt techniques traffic (Traffic Shapping) to set the packet data pursuant to the example set in the station to send data at rates exceeding the support link. ATM switch will act as a buffer packet much as possible. And forwarding the link to support that amount. Or defined. And one technique is used. Traffic policies (Traffic Policing) is sent if the cell data rate than data set will be a symbol to show that this cell has low priority (Priority) when passing it to this cell may will be abandoned or at any time, depending on the congestion of the network.

Basis of ATM

Mechanism to send data in the form of ATM transfer station is sending and receiving stations will be built virtual paths (Virtual Path) for information before you submit. Switch in the virtual path will be sent to the Packard to see a fried. Using information in the header.

Virtual Connection.

Virtual Connection can be created in the ATM network is type 2.

• Virtual Circuit:VC
• Virtual Path:VP

Virtual Circuit is a virtual connection (Logical Connection) between any two stations. Network switch Station to communicate by sending data via cell. Through virtual circuits. The virtual paths (Virtual Path) is a group of virtual circuits. The circuit as a group, it will be beneficial to manage virtual circuits that may contain several cycles at the same time. Or it is easier to manage virtual circuits instead of a separate group. 

In each cell of the ATM. Information about the virtual path. Or VPI (Virtual Path Information) and information about virtual circuits. Or VCI (Virtual Circuit Information) switch will use this information to send the cells to the appropriate device. The switch will work on this switch must be the path table (Switch Table) data in the table is a match between the VPI, VCI, and the switch interface.

Type of connection

• Point-to-point Connection
• Point-to-Multipoint Connection

For a point-to-point. And point-to-multipoint. Can create a virtual circuit is a 2-way switch or SVC (Switched Virtual Circuit) and a permanent or PVC (Permanent Virtual Circuit) is the first advantage is that PVC use a data path will be booked for sending data. only part of the SVC connection is different from PVC is to reserve bandwidth of the network depends on the data rate to send If it stops sending data during the connection. bandwidth will be left to the network while the PVC is complete when sending data bandwidth. Continue to be booked for this connection.

Devices on the network ATM.

Equipment used in the ATM network switch is only called ATM switch network that uses ATM Master-blend polo star with a central ATM switch. Network for ATM. Network card will be called UNI (User-to-Network Interface) interface that connects between the switch that triggers the NNI (Network-to-Network Interface).

Architecture of network ATM.

The protocol of the ATM is different from the protocol type is generally different protocol layers will be divided into a 2-dimensional but the protocol is ATM-3. Each dimension is called dimension. “South Plainfield, (Plane)” The players will each be set protocol that consists of 3 players each, as follows:

• Control Plane
• User Plane
• Management Plane

ATM will work in layers 1 and 2 of the OSI MODEL The protocol above is the protocol standard for the way around the protocol is divided into ATM layer. And bottom layer. This layer is on the part of the User Plane and Control Plane, User Plane is responsible for providing information about the transfer station between the sending and receiving stations, the Control Plane is responsible for the signal (Signal).

Physical Layer

Physical copies of the ATM protocol is subdivided into Class 2:

• Transmission Convergence (TC)
• Physical Medium (PMD)

TC class will be responsible for transmission to send data such as if a class will receive information from the ATM layer cells and then calculate the value Checksum for error checking and then transmitting each bit on the medium. If a data class will be run in contrast to data in the PM class will be responsible for the control signal. To synchronize real-time performance and cherished possession that depends on the type of cabling used.

ATM Adaptation Layer (AAL)