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Sonet project

  1. 1. SONETPage 2 of 32-Introduction & Objectives of theSONET………………………………………………………………………...…4-5SONET History& the CurrentTechniques……………………………………………………………………….5-6SONET Protocols, NetworkTopologies&Configurations----
  2. 2. SONETPage 3 of 32The Basic Unit of Transmission in theSONET -Turn it in Report…………………………………………………………………33
  3. 3. SONETPage 4 of 32Synchronous Optical Networking(SONET)INTRODUCTION & OBJECTIVES:-Introduction to SONET:-We know that in the modern world, an organization’s are increasingly looking forward for theresult of the character knowledge that flows through their communication networks. Thesenecessities require more effective management & identity of such knowledge flows. The tool foridentifyingsocial networks & its structures acommunication is needed. Again, the flow of suchknowledge in which social networks communicate is also to be analyzed. Thus, a research tool toanalyses such communication in course sites that use social networks was motivated to becreated. This tool was SONET. It gives the data, sound and video through the same service as anunion of technology in combination. We know that social networks are like graphs. They usenodes to constitute parties & edges to constitute the communication links. In the same way,considering knowledge management, here the nodes constitute people whereas theassociatesconstitute the transfer of knowledge from person to person.SONET falls under Physical Layer of OSI model defining the interface standards. This standardis the hierarchy is the of interface rates. It allows data streams to be multiplexed at the differentrates. Its implementation has helped the communication carriers in the world to interlink theirliving fiber optic systems & the digital carriers. Optical Carrier levels from 51.8 Mbps to 2.48Gbps can be established by the SONET.SDH is the international equivalent of SONET, which is standardized by the ITU.Also SONETnetwork components can obtain signals from different forms of facilities like DS1, DS3, LAN,
  4. 4. SONETPage 5 of 32MAN, WAN, ATM, Internet& a variety of network topologies. Moreover,it is known that eventhe SDH signals can be connected to SONET and vice versa.Objectives of SONET:-Some of the objectives of the SONET are given below:- To visualize & recognize the type of communication that occurs in a network. Recognize the knowledge hubs not contributing to the community. For synchronous networking To transport new services like the ATM. For grooming For the enhancement of OAM&P To arrange multi-point To introduce mid-span meet For the standards-based survival ringsHISTORY & CURRENT TECHNIQUES:-History:-It is known that the SONET was primitively developed for the populace telephone networking.Formerly in the 1980s, the break apart of the AT&T in United States generated various regionaltelephone companies. However, theorganizationssoon faced hardships in the networking withone another. Fiber optic cabling had so soonpersistedfor a far distance voice traffic transmission.The living networks was unnecessary costly to develop&hard to extend for a lengthy haul data &video traffic.
  5. 5. SONETPage 6 of 32Thus, the American National Standards Institute (ANSI) successfully intended SONET as thenew standard for these applications.SONET was founded in the mid 1980s by the ExchangeCarriers Standard Association (ECSA) to the American National Standards Institute (ANSI). It isconsidered as the standard for the fiber optic networks which are used widely today all over theworld. It allows multiple vendor products & technologies defining physical network interfaces.We know that the very first fiber optic network was creditworthy for equipment, procedures, linecodes, maintenances etc. The need of standard that supports in matching equipment fromdifferent vendors is being opted by the users from different companies as well as countries likeKorea, Brazil, Hong Kong, Canada, Japanetc. Like Ethernet, SONET provides aninterface layertechnology. This is because the SONET also behaves as a carrier of the multiple high levelapplication protocol.Current Techniques:-SONET is presently a grouping of physical layer constraintBased on the signaling speed hierarchy Synchronous Transport Signals (STS), SONET is just agroup of physical layer requirements. It also demonstrates the sub level of the STS-1 signals.STS-1 formats can also be subdivided into smaller segments called virtual tributaries. We knowthat these virtual tributaries are the synchronous signals which are used for the transporting thelow speed transmission.Pointers are a concept that is used to compensate frequency & phase variations. These pointersallow the transporting of the synchronous payload envelops across the boundaries transparently.The payload envelops may be either STS or virtual tributaries. They are between the nodes alongwith the separate network clocks with same timings. It is known that to avoid data loss & delays,the pointers are used widely.This table down shows the contents of the list of virtual tributaries with their sizes.
  6. 6. SONETPage 7 of 32SONET PROTOCOLS,NETWORKTOPOLOGIES&CONFIGURATIONS:-SONET Protocols:-We know different terms are used by the SONET to explain functions & features. Again, theseterms exaggerates their differences & create confusions too. It is known that the protocolsarehighly multiplexed. The header is furnished in a complex way between the data. This helps thecapsuled data to own its own frame rate. The data is locked in a different rate than frame rate soextra padding is allowed to the multiplexed data. Decision to allow extra padding in the mostlevels of multiplexing has made the protocol more complex. Here, compared to the frame rate of125 microseconds, the data sending rate is delayed by 32 microseconds.SONET Topologies:-Ring is the major deployment architecture of the SONET. Survivability is the major benefit ofthe ring architecture. ASMs can be put in ring architecture. Rings are the most
  7. 7. SONETPage 8 of 32relevantarchitectures in SONET implementation due to its redundancy.Multiplexers can sendsignals through the rings with no interruption even if the fiber is cut down.Network Architecture:-We know that the SONET has limited number of architectures which allows us for the protection& enough usage of the bandwidth. Regardless the transmission speeds, the SONET connectionuse two fiber optics.Some of the network architectures of the SONET are:- Linear Automatic Protection Switching:-Linear Automatic Protection Switching (APS) is also known as one plus one (1+1) switching. Inthis switching four fibers are included. Among which two of the fibers are working fibers & toware protection fibers each in both the directions. Here the switching is always based in the linestatus. The switching may be in unidirectional or bidirectional.
  8. 8. SONETPage 9 of 32 Unidirectional Path Switched Ring:-Two path degree transcriptsof the protected traffics are transferred to either direction across thering in Unidirectional Path Switched Ring (UPSR). Here a selector is placed at the egress nodewhich uses the copy identifying the copy that contains the maximum quality. UPRSs always sitclose to the network edge. They are called collector rings too. Total capacity of the UPSR is thesame of the line rate of the OC-N ring. This is because the data transmitted across the ring is bothdirections are always the same.
  9. 9. SONETPage 10 of 32 Bidirectional Line Switched Ring:-Bidirectional Line Switched Ring (BLSR) can be divided into two parts. They are two fibersBLSR & four fibers BLSR. BLSRs do not send path level copies from ingress to the egress sameas the UPSR. We know that anunsuccessful or sustenance action on one line cause protectionfiber which connects the two nodes needed to be employed rather than looping across the ring.So, either multiple line failures or single node failures can be supported in four fiber ring. Totalbandwidth which BLSR supports is unlimited to that of OC-N so it can move traffic betweenmetropolitan regions too. BLSR serves as a collector ring. Thus BLSR are often deployed incollector rings, inter-office rings so it is seldom in nature.
  10. 10. SONETPage 11 of 32COMPARISON WITH OTHER TECHNOLOGIES:-Comparision with ATM:-We know that ATM falls under the data link layer whereas the SONET is a physical layerapplication of the OSI model. ATM uses layer one technology to transport services. The SONETis the major technology in physical layer. This technology is commonly used by the ATM. Theremay also be other examples of the physical layer containing WAN interfaces. The ATM followsthe fixed cell length technology whereas the SONET uses a frame based technology. The ATMspecified cells are added to the frames used by the SONET through which the ATM cells aretransported.
  11. 11. SONETPage 12 of 32Many companies including the government agents use ATMs. They can achieve a lot of leverageusing the SONET transport tecnhology. This combination of ATM & the high speed SONETdevices leads the customersto satisfy through the advantages of the SONET.Comparision with FRAME RELAY:-As the SONET is a technology with rotating rings, it cures mechanically in the happening offailures. The rate of transfer in SONET begins with 155 Mbps & goes up to 9.95 Gbps. Toachieve the high speed, the SONET channels are multiplexed.We know packets are used by the frame relays which are 64-1500 bytes in size. A flag isassigned to the start & end points. Frame relays can transfer voice traffic & even video traffics. Itassists save the network bandwidth as well as to generate higher productivity of the network.SONET has a high speed as it consist optical fiber. However, frame relay can’t gain speedwithout the help of RBOC. Users of the frame relay are growing day by day. In the same way,the frame relay supports the SONET to grow the bandwidth of their network.Comparision with SDH:-It is known that the SONET & SDH standards are both specified for the data transmission overfiber optics. SONET is an American standard presented by the ANSI likewise SDH is theinternational standard presented by the ITU. The main ingredient of SDH is the STM-1 likewisethe STS-1 is the major ingredient of the SONET. However, both the SONET & the SDH containthe common OC-n that provides the midpoint meeting. OC-n signals are achieved by scramblingthe STS-n & STM-n signals. The SONET & the SDH will be incompatible if the SPE mappingsused are different.BENEFITS OF SONET:-
  12. 12. SONETPage 13 of 32The SONET has become the well-known major technology in the market against the formertelecommunication technologies. This is because of its flexibility in configuration.Some of the major merits of the SONET are provided as follows:-
  13. 13. SONETPage 14 of 32 Grooming:-Combination & separation process is exercised by the grooming in order to function in a highefficiency rate. Arrangement of multi-point:-Point-to-point configurations can only be handled by the asynchronous systems. However, theSONET handles multi point configurations as well as the hubs. These hubs support in deductingthe multiplex along with the de multiplex which supports in the traffic grooming. Reduction of cables as well as DSX panel elimination:-We know that DSX panels are the equipment of the asynchronous system. DSX panels areintended to perform grooming in synchronous network electrically. Enhancement of performance monioring:-The SONET can switch the traffic automatically as it can sense the problems with the help of thedual ring architecture. Enhancement of OAM&P:-The network vendors are excessively referred to Operation, Administration, Maintenance&Provisioning (OAM&P) process. This is because of the availability of various network providershave various products in the transmission network. OAM&P networks can be merged by the
  14. 14. SONETPage 15 of 32SONET. This will support the linking a connection to another that supports to save budget whichconnects individual networks. Optical Interconnection:-We can summarize all the advantages of the SONET in the form of compatibility, flexibility,technology & economics. STS as well as the optical carrier (OC) needed for the transmission in afiber optic cabling is included in the SONET.DISADVANTAGES OF SONET:-However, the SONET also has some limitations too. They are provided below:- Multicast traffic:-Multicast traffic requires different circuits for the individual destination. Thus, a copy iscreated in the both destinations. The result in the multiple copies of packets will deductthe bandwidth in the network. Fixed circuits:-In the SONET, the ring nodes are placed in the point-to-point circuit. The bandwidth maybe wasted if they are not used by the SONET. Thus, this causes limitations whiletransferring data & it creates bursts. Wastage of protection bandwidth:-We know that always 50 % of bandwidth is differentiated for security. However, theSONET does not follow this method. This causes the vendors difficulties to select theappropriate amount of bandwidth required for security.PROTOCOL LAYERS in the SONET STANDARD:-
  15. 15. SONETPage 16 of 32The SONET relies on the four protocol layersentire works of multiplexing, organizingtransmitting& routing frameseach of that controls each aspect of the whole transmission. Thesefour levels are given below.1. Photonic Layer:-This layer converts signals between optical & electrical form.2. Path Layer:-This layer is concerned with receiving the frames from source to destination& viceversa.3. Section layer:-This layergenerates the frames & looks after the monitoring errors in transmission.4. Line Layer:-This layerhandles the part of synchronizing, demultiplexing& multiplexing.OPERATION, MAINTENANCE & ADMINISTRATION:-The SONET also represents the management of the networks in support of the administrativefunctions, operations & maintenances. Overheads added in the SONET frame gives the controlof network monitoring & managements. It is known that the 4% of the actual bandwidth isconsumed by the overhead of network management.Some of the monitoring functions are givenbelow:-
  16. 16. SONETPage 17 of 32Failure of the systemParity errorsPointer lossFrame lossSignal lossSynchronization lossOperation:-Electrical signals are converted to the optical levels by the SONET for transmission. We knowthat the SONET is not very long & a single piece optical fiber. The transmission can transformthrough routers, repeaters & switches along with the ways from the source to destination as wellas bymore than one intermediate multiplexer to boost the signals. Transmissions amongthemselves are composed up of 810 bytes framewhich are sent out at the rate of 8000 Bps.Section: It is a single length fiberoptic cable.Line: It is a segment of the any path which travels between the two multiplexers.Path: It is the complete route between the destination multiplexer & the sourcemultiplexer.WIDE AREA NETWORK:-
  17. 17. SONETPage 18 of 32WAN stands for Wide AreaNetwork. It is a computer network which coversthe multiple distanceareas which spreadsover the whole world. The WAN joinsthe multiple smaller networks likeLAN & MAN. Internet is the world’swell-nigh popular WAN. WAN technologies usuallyoperate at the bottom three layers of the OSI reference model. Frame Relay, SONET, X.25, PPP& ATM are some of the technologies often found in WAN. SONET is considered as aninternational standard for high speed communication across fiber optic network whichestablishes Optical Carrier (OCs) levels from 51.8 Mbps to 10 Gbps& even higher.
  18. 18. SONETPage 19 of 32OVERVIEW of WAN TECHNOLOGY:-Concept of WAN technology is majorly discoursed in the physical layer & the data link layer ofOSI model. Various protocols are used there. Some of the services interleaved by WANtechnology are frame relay, HDLC. WAN technology operates on the layer 1 & layer 2 of OSImodel. Different authorities like the ISO & Telecommunication Industry Association (TIA)describe the access standard of WAN technology.The functional as well as the electrical connection are defined by the protocols in the physicallayer. Whereas encapsulation of data to unknown location is described by the protocols in thedata link layer. We know that ATMs & Frame relays are taken for frame transfers.WAN DEVICES:-Some of the components of the WAN technology are given as follow:-RoutersModemsCore RoutersAccess ServersCSU/DSUWAN switches
  19. 19. SONETPage 20 of 32SYNCHRONIZATION:-It is good to know what the plesiochronous, synchronous & asynchronous is beforeunderstanding the concept & details of the SONET. Signal occurs at the same rate insynchronous. However, the phase difference between the signals lies in their limits. Propagationdelays introduced in transmission networks creates the phase difference. Every clock is trackedtowards Primary Reference Clock (PRC) in synchronous.When two signals comes at the same rate plesiochronous is created with variation. Thus, clocksalso may be achieved when two networks are connected from two RPCs. The differences in theresult are the plesiochronous difference. Differences in the result occur even if the clocks areaccurate.Whereas in the asynchronous, signals does not come in the same rate. It is said to beasynchronous when the difference between the two clocks becomes more than theplesiochronous difference.Some of the synchronous sources available are as follows:-Local external timing:-It is created by a satellite-derived clock or an atomic Cesium clock with a device in thesame central office as the network element. Along with sync-status messages placed intothe DS1 overhead supplied by the clock, the interface is often a DS1,Holdover:-A network element reaches a holdover mode in the absence of high quality timing as alast resort until high quality timing is available. The network element uses own timingcircuits as a reference in this mode.Line-derived timing:-
  20. 20. SONETPage 21 of 32Monitoring the S1 sync-status bytes to ensure quality, a network element can beconfigured to derive its timing from the line-level.SONET EQUIPMENTS:-The traditional sections of network components are no longer distinct with advancement in theSONET chipsets. However, as new equipment can be examined in light of the architectures itsupportsthe network architectures which haverelatively remained constant. So, in terms of theold sections, there is always a value in viewing newer plus traditional equipments.Regenerators:-Only the section overhead is terminated by the traditional regenerators. Line or path is notaffected by it. Long haul routes are extended by the generators converting optical signals alreadypassed a long distance of electrical format. It also retransmits a regenerated high power signal.Regenerator has been replaced largely by optical amplifierssince late 1990s. Even thetransponders of wavelength-division multiplexing systems have absorbed some of thefunctionality of regenerators.Digital cross connect system:-DCSs or DXCs recently often supports various high speed signals. It also allows the crossconnection of the DS-1, DS-3 plus the STS-3s & other connections from one input to other.Again various subtending rings are supported by the advanced DCSs simultaneously.Add-drop multiplexer:-They are the most common network elements. Though the new generation systems oftensupportvarious architecture, the traditional ADMs were developed to operate only in onearchitecture. Traditionally ADMs have a low speed side & a high speed side that contain
  21. 21. SONETPage 22 of 32electrical plus optical interfaces. It is known that the low speed signals multiplexed by thenetwork element are taken by the low seed side & vice versa.SONET STANDARS:-Telcordia GR-253-CORE, SONET Transport Systems: Common Generic CriteriaTelcordia GR-499-CORE, Transport Systems Generic Requirements (TSGR): CommonRequirementsANSI T1.105: SONET-Basic Description including Multiplex Structure, Rates andFormatsANSI T1.119/ATIS PP 0900119.01.2006: SONET-Operations, Administration,Maintenance, and Provisioning (OAM&P) - CommunicationsITU-T recommendation G.707: Network Node Interface for the Synchronous DigitalHierarchy (SDH)ITU-T recommendation G.783: Characteristics of synchronous digital hierarchy (SDH)equipment functional blocksITU-T recommendation G.803: Architecture of Transport Networks Based on theSynchronous Digital Hierarchy (SDH)
  22. 22. SONETPage 23 of 32NEXT GENERATION of SONET:-The requirement to transport multiple PDH signals in the network drove to the creation of theSONET. Some of the transport multiple PDH signals areDS1, DS3, E1, E3 etc. Moreover, otherchunks of multiplexed 64 kbps pulse code modulated voice trafficare also considered as the PDHsignals. Nextformer application was the power to transport ATM traffic. In order to help a hugemass of the ATM bandwidtha concatenation has beendeveloped, where small multiplexcontainers are oppositely multiplexed to create ahuge container. This helps out the huge dataoriented pipes.However, inflexibility is one of the major problem with traditional concatenation. This dependson the data & voice traffic mix which is required to be carried.The fixed size of concatenatedcontainers creates a huge mass of unused bandwidth left over due to the fixed sizes ofconcatenated containers. For an instance, if a fitting of 100 Mbps Fast Ethernet connection insidea 155 Mbps STS-3c container will lead to considerable waste of the bandwidth. It is vital needfor all the intermediate network components to support newly introduced concatenation sizes.The introduction of Virtual Concatenation has solved this problem.Arbitrary assembly of the low order multiplexing container, creating huge containers of arbitrarysize up to 100 Mbps is done by the Virtual concatenation (VCAT).It can be done without thespecifications for intermediate network elements that support this type of concatenation. Virtualconcatenation leverages the X.86 or Generic Framing Procedure (GFP) protocols. In order tomap payloads of arbitrary bandwidth to virtually-concatenated container, multiplexing containersbased on the short term bandwidth requires the network. We know that the dynamicallyalterthrough dynamic virtual concatenation in the bandwidth is possible by the Link CapacityAdjustment Scheme (LCAS).Ethernet over SONETis referred as the set of the next-generation SONET protocols which allowsEthernet transport.SONET HIERARCHY:-
  23. 23. SONETPage 24 of 32DEPLOYMENT of SONET:-We know that the SONET equipment is deployed in various sectors by the service providers.Various companies, public-service corporation, governments as well as high level clients haveadopted deploying the SONET. Nowadays SONET has become so popular among all categoriesof customers. This is because the SONET has a lot of advantages like scalability, reliability, highperformance rates etc. SONET is being used in the customers’ self-governance or in a jointcentral office. Their main objective is to achieve WAN connectivity.SONET is being used for the transporting process of the ATM, Frame relay, DS-1, IP etc. toother services.This is done by the support of hub based & ring based configuration. The mostpopular SONET topology is ring based configuration. It helps in the network’s survivability.Implementation of dual ring configuration is required to achieve further more survivability.
  24. 24. SONETPage 25 of 32SONET SIGNAL:-The SONET technology carries signals containing various capacities across the synchronous &flexible hierarchy that achieves the bytes provided multiplexing connive. It is also simplifiedwith the byte provided to it.The first step in SONET multiplexing is to create the base signal which operates at the speed of51.84 Mbps. It is also regarded as Synchronous Transport Signal, level 1 (STS-1). Generations ofthe family of STS-N signals takes place by the occurrence of various levels. Here is the tabledefining the OC as well as the synchronous signals.THE BASIC UNIT OF TRANSMISSION IN SONET:-
  25. 25. SONETPage 26 of 32In SONET, STM-1 (Synchronous Transport Module, level 1) is the basic unit of framing. Itoperates at 155.52 Mbps. We know that SONET refers to it as the STS-3c (SynchronousTransport Signal, concatenated 3).This depends on whether the signal is carried optically orelectrically. However, its bit rate, frame size& function is same to the STM-1.Again, it is known that the SONET offer additional basic unit of transmission. The speed ofoperation is 51.84 Mbps which is the one third to STM-1, STS-3c & OC-3c carrier. This speed isdetermined to bandwidth specification for PCM encoded voice in telephone signals at the rate inwhich a STS-1 & OC-1 circuit carry bandwidth equal to the standard DS-3 channel. DS-3channel carries 672.64 Kbps voice. STS-3c & OC-3c signals are composed of three multiplexedSTS-1 signal. Even STM-0 is support the SONET equivalent to the STS-1 & OC-1.1. Framing:-Packet oriented data transmission like Ethernet usually contain a packet frame of header & apayload. Here at first the header is transmitted then the payload. However, in SONET this isslightly modified. Instead of transmitting the payload first, the header is termed as the overheadis interleaved during the transmission with it. First part of the overhead is transmitted & next thepart of payload. Again, the part of overhead then part of payload till the whole frame’stransmission is completed.The frame is of size 810 octets in the case of the STS-1 whereas the STM-1 & STS -3c frame isof 2430 octets. The frame is transmitted 3 octets overhead for STS-1 with payload of 87 octets.This process repeats for nine times till 810 octets is transmitted per 125 Mbps. 9 octets ofoverhead are transmitted following 261 octets of payload in STS-3c & STM-1 that functionsthrice fast than STS-1. This process again repeats till nine time. By this time 2430 octets istransmitted per 125 Mbps. This is represented displaying frame graphically in SONET in 90columns & 9 rows to the STS-1 & 270 columns & 9 rows to the STM-1 & STS-3c. Thus,overhead as contiguous block like payload in this representation.We use STS-1 & 270 columns interchangeably in practice. However, the OC designations referto signals in optical form. Thus, it is inaccurate to say that OC-3 consists three layers. But we cansay that it consist three STS-1s.
  26. 26. SONETPage 27 of 322. SDH frame:-The first 9 columns are the overhead & the pointers in STM-1 frame. For simplicity, frame hereis shown rectangular with 270 columns & 9 rows. However, the bytes are not transmitted in thisorder by the protocol.
  27. 27. SONETPage 28 of 32We know that STM-1 frame transmits in 125 Mbps. So, on a fiber optic circuit of 155.52 MbpsOC-3, there are about 8,000 frames. This frame contains pointers, overhead & InformationPayload (IP). Administrative Unit Pointers (AUP) & Section Overhead (SO) is made up of thefirst 9 columns of the frame. The remaining 261 columns makes Information Payload. Within theinformation payload, Administration Units (AU) are identified by the pointers (H1, H2, H3bytes). Hence, after accounting for the overhead, OC-3 circuit carries 150.336 Mbps of payload.Administrative Units are carried within information payload, with their own frame structuresconsisting 261 columns & 9 rows recognized by pointers. There are more than one virtualcontainers (VC) within the Administrative Units too which consists of VC payload & pathoverhead. We know that path overhead is at the first column which is followed by the payloadcontainer. The pointer indicates the row four where the Administrative Units contain their phasealignment inside STM frame.
  28. 28. SONETPage 29 of 32Now the section overhead is divided into two groups. They are Regenerator Section Overhead(RSOH) & Multiplex Section Overhead (MSOH). Te information gained by the overhead fromtransmission system is then utilized for a broad range of the management function. This can befor service channels, detecting failures data communication monitoring transmission quality etc.Byte-by-byte & row-by-row is a serial fashion how the STM is transmitted in a continuous way.3. Transport overhead:-For measuring &signaling transmission error ratesthe transport overhead is used.It is composedin the following way:- Section overhead:-It is called Regenerator Section Overhead (RSOH) in SONET terminology. Here, thereare 27 octets which consist of information related to frame structure that is neededalongthe end equipment. Line overhead:-It is called Multiplex Section Overhead (MSOH) in SONET terminology.Here, there are45 octets which consist of information related to the Automatic Protection Switchingmessages like maintenance messages, alarms &error correction as they may beneededalong networks. AU Pointer:-It points towards location of first byte in the virtual container i.e. J1 byte in the payload.4. Path virtual envelope:-Path data is the data transmitted from end to end. It is broken down into two parts:- Payload overhead (POH):-Payload overhead employs 9 octets for end-to-end error measurement& signaling.
  29. 29. SONETPage 30 of 32 Payload:-STS-1 payload carries a complete PDH DS3 frames. Path overhead is added when the DS3enters a SONET network. The SONET network element entering the SONET network is the pathterminator or the generator. If the path or the line ended then the section is terminated too. It isknown that the line or the path is terminated by the SONET regenerators.To form other degree of the SONET hierarchy, three STS-1 signals are multiplexed. This signalmultiplexed by the interleaving bytes of 3 STS-1 frame forms STS-3 frames which consists2,430 bytes that transmits in 125 Mbps.We know that Dense Wave Division Multiplexing (DWDM) are the circuits which are used asthe basis to long haul circuits & all modern submarine communication cable systems.COST:-However, the SONET technology is costly. It provides its services at about 20% higer than theother services in the market. Again, the prediction of the SONET technology’s world market isincreasingly 17.4 % every year. This has proved that the SONET technology is going to rule theentire world in the near future.CONCLUSION:-We have now come to know that the SONET has specialized various standards needed to insuredata communication & efficiency. This has supported a lot to the customers in the standardcommunication. Applications like teleconferencing, HDTV etc. has been created with thecombination of the telephone & data communication. These need a high mass of bandwidth. It isknown that it is only SONET that provides the large amount of bandwidth. SONET has a speedof 10 Gbps for the data communication & voice traffic. This is why all the vendors have realizedthe importance of the SONET technology.
  30. 30. SONETPage 31 of 32Now we have been cleared that the SONET is the only technology which is most efficient toevery users in the whole world.ACKNOWLEDGEMENT:-hard to make a reliable & appreciable . I have gonethrough the various curriculums, deep on SONET to make my project much worthy.have through related websites links.Mr. Ayush Mani Subedi. Hehasassist me in collecting suggest me toinclude all the fundamental features & functions. my colleaguestechnically & morally.
  31. 31. SONETPage 32 of 32- Webpage Links:--