Virtual paths can be permanent or switched. A permanent virtual path is established by the network manager and exists for a long period of time, often for the life of the network. Virtual circuits can be routed over the existing permanent virtual circuits. It is also possible to have switches that route virtual paths. Because permanent virtual paths are simpler, most ATM networks use permanent virtual circuits.
Frame is sent row wise.
Three bytes of control are sent followed by 87 bytes of data then the next 3 bytes of control and the next 87 bytes of data until the whole frame is sent. A TM A daptation L ayers ATM provides several different services. The ATM Adaptation Layers correspond closely to the ATM classes Higher level protocols call the Adaptation Layer to send a block of data. The Adaptation Layer adds its own header and trailer to the data. The large block is then divided into 48 byte pieces, which are sent in ATM cells.