1、ATM over SONETKavitha Sriraman,1,ATM Over SONET,By: Kavitha Sriraman, CEPE, Dept of ECE, Drexel University, Email : kavithadrexel.edu,ATM over SONETKavitha Sriraman,2,What is ATM over SONET?,prevalent in the Computer Networking for transmitting of Internet Packets. optical layer provides the foundat
2、ion of transport services for both metro and long-haul applications. . Transporting Layer is the ATM.,ATM over SONETKavitha Sriraman,3,SONET?,Synchronous Optical NETwork. Synchronous, Asynchronous, Plesiochronous. Plesiochronous difference. Data rate,ATM over SONETKavitha Sriraman,4,SONET SIGNAL.,de
3、fines a technology for carrying many signals of different capacities through a synchronous, flexible, optical hierarchy Byte interleaving. SONET multiplexing involves the generation of the lowest level or base signal- STS1operates at 51.84 Mbps. Higher-level signals are integer multiples of STS1, cr
4、eating the family of STSN signals,ATM over SONETKavitha Sriraman,5,SONET SIGNAL TABLE.,ATM over SONETKavitha Sriraman,6,SONET FRAME FORMAT,divided into two main areas: transport overhead and the synchronous payload envelope (SPE). SPE divided into two parts: the STS path overhead (POH) and the paylo
5、ad. Once the payload is multiplexed into the synchronous payload envelope, it can be transported and switched through SONET without being examined and possibly de-multiplexed at intermediate nodes service-independent or transparent .,ATM over SONETKavitha Sriraman,7,Transmission Of Signals in SONET,
6、signal into containers. Adds the section overhead signal and the quality of transmission are all traceable. containers have two names depending on size: virtual tributary (VT) or a synchronous payload envelope (SPE). path overhead contains data to control the facility (end to end) such as for path t
7、race, error monitoring, far-end error, or virtual container (VC) composition.packaged in VCs and transported in synchronous transport vehicles or signals (STS).,ATM over SONETKavitha Sriraman,8,Transmission Of Signals in SONET,ATM over SONETKavitha Sriraman,9,Transmission Of Signals in SONET contd,A
8、n STS exists on each section (i.e., the link between two nodes), also contains the line or section overhead. This line/section overhead contains data to control the node-to-node transmission (protection switching, error monitoring), and, in addition, provides extra channels (network management and m
9、aintenance phone link). line transmission rates are 51, 155, and 622 Mbps; 2.5 Gbps; and 10 Gbps.Line signals can be optical or electrical. Electrical signals are used for short distances.,ATM over SONETKavitha Sriraman,10,Transmission Of Signals in SONET contd,ATM over SONETKavitha Sriraman,11,Asyn
10、chronous Transfer Mode,A high-performance, cell-oriented switching and multiplexing technology that utilizes fixed-length packets to carry different types of traffic. fixed-length cells consisting of 48 bytes (8 bits per byte) of payload and 5 bytes of cell header ensures that time-critical informat
11、ion such as voice or video is not affected by long data frames or packets. header is organized for efficient switching,ATM over SONETKavitha Sriraman,12,ATM Connections,virtual path connections (VPCs), which contain virtual channel connections (VCCs). A virtual channel connection (or virtual circuit
12、) is the basic unit, which carries a single stream of cells, in order, from user to user. All cells belonging to a particular virtual path are routed the same way through the ATM network faster recovery in case of major failures. Virtual circuits can be statically configured as permanent virtual cir
13、cuits (PVCs) or dynamically controlled via signaling as switched virtual circuits (SVCs)a rich set of service capabilities.SVCs are the preferred mode of operation dynamically established minimizing reconfiguration complexity,ATM over SONETKavitha Sriraman,13,Structure to Carry Data,ATM cells does n
14、ot have the structure. SONET provides the VT (containers). its filled with cells (ATM ) of 53 bytes. Higher Data Rate the cells are concatenated.,ATM over SONETKavitha Sriraman,14,Conclusion.,high performance via hardware switching dynamic bandwidth for bursty traffic class-of-service support for multimedia traffic. scalability in speed and network size provide a range of data, image, video and voice services that take advantage of increasing insensitivity of the network to distance.,
