ATM over SONET~Kavitha Sriraman1 ATM Over SONET By: Kavitha Sriraman, CEPE, Dept of ECE, Drexel University,

ATM over SONET~Kavitha Sriraman2 What is ATM over SONET?? prevalent in the Computer Networking for transmitting of Internet Packets. optical layer provides the foundation of transport services for both metro and long- haul applications.. Transporting Layer is the ATM.

ATM over SONET~Kavitha Sriraman3 SONET?? Synchronous Optical NETwork. Synchronous, Asynchronous, Plesiochronous. Plesiochronous difference. Data rate

ATM over SONET~Kavitha Sriraman4 SONET SIGNAL. defines 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- STS–1 operates at Mbps. Higher-level signals are integer multiples of STS–1, creating the family of STS–N signals

ATM over SONET~Kavitha Sriraman5 SONET SIGNAL TABLE. SignalBit Rate (Mbps)Capacity STS–1, OC– DS–1s or 1 DS–3 STS–3, OC– DS–1s or 3 DS–3s STS–12, OC– DS–1s or 12 DS–3s STS–48, OC–482, ,344 DS–1s or 48 DS–3s STS–192, OC–1929, ,376 DS–1s or 192 DS– 3s Note: STS = synchronous transport signal; OC = optical carrier SignalBit Rate (Mbps)Channels DS– DS–0 DS– DS–0s DS– DS–0s DS– DS–1s

ATM over SONET~Kavitha Sriraman6 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 payload. 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 SONET~Kavitha Sriraman7 Transmission Of Signals in SONET 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 trace, error monitoring, far-end error, or virtual container (VC) composition. packaged in VCs and transported in synchronous transport vehicles or signals (STS).

ATM over SONET~Kavitha Sriraman8 Transmission Of Signals in SONET

ATM over SONET~Kavitha Sriraman9 Transmission Of Signals in SONET contd.. An 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 maintenance 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 SONET~Kavitha Sriraman10 Transmission Of Signals in SONET contd.. Bit Rate (Mbps ) PDH North AmericaPDH EuropeSDHSONET NameBit Rate (Mbps ) NameBit Rate (Mbps ) ContainerTransportContainerTransport 10,000 STM–64 STS/OC–192 2,500 STM–16 STS/OC– STM–4 STS/OC– STM–1 STS/OC–3 140 E4140VC4 51 STS/OC–1

ATM over SONET~Kavitha Sriraman11 Asynchronous 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 information such as voice or video is not affected by long data frames or packets. header is organized for efficient switching

ATM over SONET~Kavitha Sriraman12 ATM Connections virtual path connections (VPCs), which contain virtual channel connections (VCCs). A virtual channel connection (or virtual circuit) 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 circuits (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 SONET~Kavitha Sriraman13 Structure to Carry Data ATM cells does not 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 SONET~Kavitha Sriraman14 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.