10 OTN基本原理（初級(jí)篇）北研

OTN基本原理（初級(jí)篇）承載網(wǎng)規(guī)劃系統(tǒng)部孫萍課程目標(biāo)了解OTN目錄Where? （15’）What? （20’）How? （50’）三個(gè)問題Where？高速數(shù)字傳輸網(wǎng)的發(fā)展產(chǎn)生背景主傳數(shù)據(jù)，少量語(yǔ)音業(yè)務(wù)突發(fā)為主業(yè)務(wù)量多，爆炸式增長(zhǎng)光纖+多波長(zhǎng)OTUkOTNG.709主傳語(yǔ)音，少量數(shù)據(jù)業(yè)務(wù)確定+突發(fā)業(yè)務(wù)量較多光纖+單波長(zhǎng)STM16SONET/SDHG.707主傳語(yǔ)音業(yè)務(wù)確定為主業(yè)務(wù)量較少光纖+單波長(zhǎng)T1/E1第一代第二代第三代Where?O T NNetwork網(wǎng)絡(luò)，網(wǎng)狀物Transport傳送，運(yùn)輸Optical光學(xué)的Optical

TransportNetworkWhere?Optical

TransportNetworkWhere?統(tǒng)一成幀為何成幀？

OTN有什么用？客戶信號(hào)幀格式SDH9行270*N列的字節(jié)幀，N為SDH速率等級(jí)。STM-1的速率為155.52Mbps，STM-N的速率等于N*155.52MbpsGE，F(xiàn)C，Escon等數(shù)據(jù)業(yè)務(wù)8b/10b編碼，相當(dāng)于幀長(zhǎng)為10位的幀10GE-LAN64/66b編碼，相當(dāng)于幀長(zhǎng)為66b的幀OTUk4行4080列的字節(jié)幀客戶信號(hào)幀格式、速率不統(tǒng)一Where?統(tǒng)一成幀為何要定義統(tǒng)一的幀格式？識(shí)別所有類型客戶信號(hào)的幀格式，性能檢測(cè)成本很高客戶信號(hào)無(wú)法業(yè)務(wù)匯聚，極大浪費(fèi)波長(zhǎng)上的帶寬能提供波分設(shè)備專用開銷，提高設(shè)備的維護(hù)管理能力OTN有什么用？Where?大容量傳送（Tbit級(jí)，波分復(fù)用原理）強(qiáng)大的網(wǎng)維管理功能（電層開銷，光層開銷）OTN設(shè)備互連互通（統(tǒng)一的標(biāo)準(zhǔn)）運(yùn)行商的成本降低（網(wǎng)絡(luò)層次減少）OTN有什么用？目錄Where? （15’）What? （20’）How? （50’）三個(gè)問題What?OTN是ITU制定的光傳送網(wǎng)標(biāo)準(zhǔn)內(nèi)容標(biāo)準(zhǔn)框架G.871體系架構(gòu)G.872結(jié)構(gòu)和映射G.709設(shè)備功能特征G.798性能G.8201,G.8251物理層G.664,G.693,G.959.1設(shè)備管理特性G.874,G.874.1,G.875,G.7710保護(hù)G.873.1What?波分設(shè)備的基本功能將各種客戶業(yè)務(wù)封裝到特定幀格式變成帶波長(zhǎng)的光信號(hào)將許多不同波長(zhǎng)的特定幀格式匯聚到一根光纖中OTN是一種設(shè)備實(shí)現(xiàn)長(zhǎng)距離大容量業(yè)務(wù)傳送What?波分設(shè)備的基本單元OTN是一種設(shè)備業(yè)務(wù)接入單元客戶業(yè)務(wù)特定波長(zhǎng)特定幀格式的信號(hào)業(yè)務(wù)接入單元客戶業(yè)務(wù)特定波長(zhǎng)特定幀格式的信號(hào)業(yè)務(wù)接入單元客戶業(yè)務(wù)特定波長(zhǎng)特定幀格式的信號(hào)波長(zhǎng)調(diào)度單元特定波長(zhǎng)特定幀格式的信號(hào)特定波長(zhǎng)特定幀格式的信號(hào)特定波長(zhǎng)特定幀格式的信號(hào)合分波單元多波長(zhǎng)光信號(hào)光線路處理單元光線路信號(hào)監(jiān)控管理單元電中繼單元What?OTN和波分設(shè)備的關(guān)系OTN是將波分設(shè)備抽象化的結(jié)果波分設(shè)備信號(hào)和OTN各層的對(duì)應(yīng)關(guān)系OTN是一種設(shè)備特定波長(zhǎng)特定幀格式信號(hào)OCH層特定幀格式信號(hào)OTUk層合波處理后的多波長(zhǎng)信號(hào)OMS層光線路處理后的信號(hào)OTS層What?也表示OTN設(shè)備組成的網(wǎng)絡(luò)OTN網(wǎng)絡(luò)的特點(diǎn)網(wǎng)絡(luò)內(nèi)部，信號(hào)格式統(tǒng)一節(jié)點(diǎn)間傳送的只有OTM信號(hào)OTN是一個(gè)網(wǎng)絡(luò)What?OTN是一個(gè)網(wǎng)絡(luò)What?OTM-nr.m

（波分設(shè)備最終輸出的主光信號(hào)）由多個(gè)波長(zhǎng)組成，每個(gè)波長(zhǎng)都有特定的幀格式（OTUk）n=波長(zhǎng)數(shù)，r=不支持光層開銷和光監(jiān)控通道，m=速率等級(jí)用于和其他廠家的波分設(shè)備互連（在波長(zhǎng)級(jí)互連）OTN是一種信號(hào)What?OTM-0.m0=沒有波長(zhǎng)，沒有光層開銷，不支持光監(jiān)控通道有特定幀格式（OTUk）m=速率等級(jí)用于和其他廠家的波分設(shè)備互連（OTUk互連）OTN是一種信號(hào)What?OTM-n.m

（波分設(shè)備最終輸出的主光信號(hào)）由多個(gè)波長(zhǎng)組成，每個(gè)波長(zhǎng)都有特定的幀格式（OTUk）同時(shí)支持光層開銷（OOS）和光監(jiān)控通道n=波長(zhǎng)數(shù)，m=速率等級(jí)用于自己的波分設(shè)備間互連，無(wú)法和其他廠家波分設(shè)備互通OTN是一種信號(hào)What?OTN是OTUk（

OpticalchannelTransportUnit）從狹義的角度，OTN就是OTUk幀OTUk幀是OTN信號(hào)在電層的幀格式OTM可以理解為n個(gè)OTUk同時(shí)傳送OTN是一種信號(hào)ODUkOHFAOHOTUkOHOTUkFEC151617……38243825…4080OTUk1……78……141234OPUkOHClientSignalmappedinOPUkPayloadWhat?ITU制定的光傳送網(wǎng)標(biāo)準(zhǔn)一種設(shè)備一個(gè)網(wǎng)絡(luò)一種信號(hào)小結(jié)——OTN是目錄Where? （15’）What? （20’）How? （50’）三個(gè)問題How?OTUk的幀結(jié)構(gòu)kindicatestheorder:12.5G210G340GODUk

-OpticalChannelDataUnitODUkOHFrameAlignmentFAOHOTUk

-OpticalChannelTransportUnitOTUkOHOTUkFEC151617……38243825…4080OTUk1……78……141234OPUk-OpticalChannelPayloadUnitOPUkOHOPUkPayloadClientSignalClientSignalmappedinOPUkPayloadHow?大顆粒業(yè)務(wù)，2.5G/10G/40G低速ODUi可完全裝入高速ODUk的凈荷，進(jìn)行匯聚，開銷獨(dú)立幀速率針對(duì)SDH設(shè)計(jì)FEC開銷，提高OTUk幀的傳送能力字節(jié)調(diào)整技術(shù)比SDH的指針調(diào)整簡(jiǎn)單開銷（不含F(xiàn)EC）比例低，維護(hù)管理功能強(qiáng)OTUk幀可方便的接入GE或10GE以太網(wǎng)業(yè)務(wù)OTUk幀的特點(diǎn)How?OPUk幀為實(shí)現(xiàn)將業(yè)務(wù)裝入OTUk幀而設(shè)計(jì)各種業(yè)務(wù)裝入凈荷部分開銷和業(yè)務(wù)映射有關(guān)OTUk,ODUk,OPUk的區(qū)別和聯(lián)系151617……38243825…40801……78……141234OPUk-OpticalChannelPayloadUnitOPUkOHOPUkPayloadHow?ODUk幀電層處理時(shí)用到對(duì)OTUk做電再生處理電層交叉調(diào)度OPUk加上一些維護(hù)管理開銷組成ODUkOTUk,ODUk,OPUk的區(qū)別和聯(lián)系151617……38243825…40801……78……141234OPUkOHOPUkPayloadODUkOHODUk

-OpticalChannelDataUnitHow?OTUk幀讓ODUk幀能在光纖中傳輸開銷用于外部傳輸OTUk,ODUk,OPUk的區(qū)別和聯(lián)系ODUkOHFAOHOTUkOHOTUkFEC151617……38243825…40801……78……141234OPUkOHOPUkPayloadFrameAlignmentOTUk

-OpticalChannelTransportUnitOTUkHow?聯(lián)系OPUk幀是ODUk幀的一部分ODUk幀是OTUk幀的一部分OTUk,ODUk,OPUk的區(qū)別和聯(lián)系ODUkOPUkHow?OPUk（kbit/s） "STM-N"*238/(239-k)ODUk（kbit/s） "STM-N"*239/(239-k)OTUk（kbit/s） "STM-N"*255/(239-k)OTU,ODU,OPU速率等級(jí)ODUkOHFAOHOTUkOHOTUkFEC151617……38243825…40801……78……141234OPUkOHOPUkPayload16Bytes3808Bytes256Bytes16/16=13808/16=238256/16=16238+1=239239+16=255How?OTU,ODU,OPU速率等級(jí)kOPUk（kbit/s）"STM-N"*238/(239-k)12488320.000（2488320*238/238）29995276.962（9553280*238/237）340150519.322（39813120*238/236）ODUk（kbit/s）"STM-N"*239/(239-k)2498775.126（2488320*239/238）10037273.924（9553280*239/237）40319218.983（39813120*239/236）OTUk（kbit/s）"STM-N"*255/(239-k)2666057.143（2488320*255/238）10709225.316（9553280*255/237）43018413.559（39813120*255/236）注：bitratetolerance=±20ppmHow?幀結(jié)構(gòu)和長(zhǎng)度不變（SDH不同速率，幀長(zhǎng)不同）不同速率等級(jí)，幀周期不同（SDH固定8k幀周期）OTN幀的周期OTU/ODU/OPUtypePeriod（note）OTU1/ODU1/OPU148.971usOTU2/ODU2/OPU212.191usOTU3/ODU3/OPU33.035usNOTE-Theperiodisanapproximatedvalue,roundedto3digits.OTUkOHODUkoverheadarea123456789101112131415161234OPUkoverheadHow?幀同步開銷開銷FASMFASFAS FramealignmentsignalMFAS Multiframealignmentsignal0xF6F6F62828

28256幀How?OTUk

OH開銷ODUkoverheadareaFASSM123456789101112131415161234OPUkoverheadMFASRESGCC0SM OTUksectionmonitoringoverheadGCC0 OTUkgeneralcommunicationchannel0RES OTUkreservedoverhead，all"0"How?OTUkSM開銷——OTUkOHSM123TTIBIP-8TTI trailtraceidentifierBIP-8 bitinterleavedparitySMRESGCC0How?SMTTI蹤跡標(biāo)識(shí)符，標(biāo)示OTUk幀的起點(diǎn)和終點(diǎn)每幀一個(gè)字節(jié)，64字節(jié)包括3個(gè)字段SAPI，標(biāo)示源地址DAPI，標(biāo)示目的地址用戶自定義信息開銷——OTUkOHSM123TTIBIP-8SAPIDAPIOperatorspecific0|1516|3132|63How?開銷——OTUkOHSM123TTIBIP-8SMBIP-8校驗(yàn)OPUk幀是否有誤碼一個(gè)字節(jié)第i幀15至3824列的所有字節(jié)（OPUk幀）異或結(jié)果，放入第i+2幀的BIP-8字節(jié)一般對(duì)應(yīng)性能量xx-BIP-8誤碼數(shù)SM、PM、6個(gè)TCM中都有BIP8開銷，計(jì)算的內(nèi)容和方法相同，開銷位置不同，作用范圍不同How?SM

BIP-8開銷——OTUkOHHow?OTUkSM開銷——OTUkOHSM123TTIBIP-812345678BEI/BIAEBDIIAERESRES bitsreservedforfutureinternationalstandardization all"0"BDI backwarddefectindicationBEI backwarderrorindicationBIAE backwardincomingalignmenterrorIAE incomingalignmenterrorSMRESGCC0How?反向開銷正向和反向，相對(duì)于同一個(gè)站點(diǎn)而言本站點(diǎn)的發(fā)送為正向，本站點(diǎn)的接收為反向開銷——OTUkOHC站點(diǎn)A站點(diǎn)B站點(diǎn)OTUkOTUkOTUkOTUkA到B的反向A到C的反向A到C的正向A到B的正向How?反向開銷本站點(diǎn)的接收為反向，和接收OTUk有關(guān)的開銷本站點(diǎn)發(fā)出去的反向開銷，根據(jù)本站點(diǎn)的接收的結(jié)果產(chǎn)生OTN中現(xiàn)在定義的，都是錯(cuò)誤指示信息開銷——OTUkOHC站點(diǎn)A站點(diǎn)B站點(diǎn)OTUkOTUkOTUkOTUk收到反向錯(cuò)誤指示?OKHow?SMBEI反向錯(cuò)誤指示4個(gè)比特，為1～8時(shí)，表示BIP-8校驗(yàn)出的錯(cuò)誤數(shù)SMBIAE反向幀對(duì)齊錯(cuò)誤在接收檢測(cè)到IAE時(shí)，在發(fā)送自動(dòng)插入BIAE一般用來(lái)屏蔽下游的反向誤碼檢測(cè)，防止出現(xiàn)檢測(cè)錯(cuò)誤開銷——OTUkOH12345678BEI/BIAEBDIIAERESHow?SMBEI/BIAE開銷——OTUkOH12345678BEI/BIAEBDIIAERESOTUkSMBEI/BIAEbits1234BIAEBIPviolations備注0001～1000false1~8BIP-8校驗(yàn)后的錯(cuò)誤數(shù)0000，1001，1010，1100～1111false0BIP-8校驗(yàn)后無(wú)誤碼1011true0代表BIAE信號(hào)How?SMBDI反向失效指示1位0 無(wú)反向業(yè)務(wù)失效1 有反向業(yè)務(wù)失效一般接收口檢測(cè)到LOF或LOM時(shí)，發(fā)送口會(huì)插入BDI開銷——OTUkOH12345678BEI/BIAEBDIIAERESHow?SMIAE幀對(duì)齊錯(cuò)誤1位OTUk幀出現(xiàn)幀頭間隔不是一個(gè)幀周期的現(xiàn)象一般用來(lái)屏蔽下游的誤碼檢測(cè)，防止因幀對(duì)齊錯(cuò)誤導(dǎo)致誤碼檢測(cè)不準(zhǔn)開銷——OTUkOH12345678BEI/BIAEBDIIAERESHow?OTUkGCC0GCC共3組，每組2個(gè)字節(jié)用來(lái)傳送網(wǎng)管信息，對(duì)應(yīng)我們?cè)O(shè)備的電監(jiān)控通道功能GCC1和GCC2在ODUk開銷中GCC0在OTUk終結(jié)點(diǎn)之間，提供一條通用通訊通道GCC1和GCC2在ODUk終結(jié)點(diǎn)之間，提供一條通用通訊通道開銷——OTUkOHSMRESGCC0How?FEC（Forwarderrorcorrection）糾正傳輸中產(chǎn)生的誤碼每行，239字節(jié)的信息+16字節(jié)的FEC校驗(yàn)字節(jié)最大糾錯(cuò)能力是8個(gè)字節(jié)準(zhǔn)確檢測(cè)到最多16字節(jié)的錯(cuò)誤開銷FAOHOTUkFECRS(255,239)orall-0s(4×256bytes)15……38243825……4080OTUk1……78……141234How?ODUkOH開銷ODUkoverheadareaFASOTUkOH123456789101112131415161234OPUkoverheadMFASRESTCM3GCC1TCMACTTCM6TCM5TCM4FTFLTCM2TCM1PMEXPGCC2APS/PCCRESPM ODUkpathmonitoringoverheadTCM ODUktandemconnectionmonitoringoverheadGCC1,GCC2 ODUkgeneralcommunicationchannelsAPS/PCCODUkautomaticprotectionswitchingandprotectioncommunicationchannelFTFL ODUkfaulttypeandfaultlocationreportingcommunicationchannelEXP ODUkexperimentaloverheadRES ODUkreservedoverheadTCMACT ODUktandemconnectionmonitoringactivation/deactivationHow?ODUk

PM開銷——ODUkOHPM123TTIBIP-8SAPIDAPIOperatorspecific0|1516|3132|6312345678BEIBDISTATTTI trailtraceidentifierBIP-8 bitinterleavedparityBDI backwarddefectindicationBEI backwarderrorindicationSTAT statusbitsindicatingthepresenceofamaintenancesignal1234567891011121314234RESTCM3GCC1TCMACTTCM6TCM5TCM4FTFLTCM2TCM1PMEXPGCC2APS/PCCRESHow?PM

BEI開銷——ODUkOH12345678BEIBDISTATODUkPMBEIbits1234BIPviolations備注0001～10001~8BIP-8校驗(yàn)后的錯(cuò)誤數(shù)0000，1001～11110BIP-8校驗(yàn)后無(wú)誤碼How?ODUk

STAT3個(gè)比特，表示有維護(hù)信號(hào)維護(hù)信號(hào)時(shí)，PM其他字段可以為全“1”、重復(fù)01100110

或重復(fù)01010101開銷——ODUkOH12345678BEIBDISTATPMbyte3bits678Status000，010，011，100Reservedforfutureinternationalstandardization001Normalpathsignal101Maintenancesignal:ODUk-LCK110Maintenancesignal:ODUk-OCI111Maintenancesignal:ODUk-AISHow?ODUk

TCMiOH6個(gè)TCM每個(gè)TCM有3個(gè)字節(jié)開銷——ODUkOH1234567891011121314234RESTCM3GCC1TCMACTTCM6TCM5TCM4FTFLTCM2TCM1PMEXPGCC2APS/PCCRESODUk

TCMi123TTIiBIP-8i12345678BEIi/BIAEiBDIiSTATiTTI trailtraceidentifierBIP-8 bitinterleavedparityBDI backwarddefectindicationBEI/BIAE backwarderrorindicationandbackwardincomingalignmenterrorSTAT statusbitsindicatingthepresenceofTCMoverhead,incomingalignmenterror,oramaintenancesignalHow?嵌套和瀑布式應(yīng)用開銷——ODUk

TCMiOHTCM6TCM5TCM4TCM3TCM2TCM1TCM6TCM5TCM4TCM3TCM2TCM1TCM6TCM5TCM4TCM3TCM2TCM1TCM6TCM5TCM4TCM3TCM2TCM1TCM6TCM5TCM4TCM3TCM2TCM1TCM6TCM5TCM4TCM3TCM2TCM1A1B1C1C2B2B3B4TCM6TCM5TCM4TCM3TCM2TCM1A2C1-C2B1-B2B3-B4A1-A2How?重疊式應(yīng)用開銷——ODUk

TCMiOHTCM6TCM5TCM4TCM3TCM2TCM1TCM6TCM5TCM4TCM3TCM2TCM1TCM6TCM5TCM4TCM3TCM2TCM1TCM6TCM5TCM4TCM3TCM2TCM1TCM6TCM5TCM4TCM3TCM2TCM1A1B1C1A2C1-C2B1-B2A1-A2C2B2A1-A2B1-B2C1-C2A1B1C1C2B2A2How?ODUk

TCMi

STAT3個(gè)比特表示有維護(hù)信號(hào)開銷——ODUk

TCMiOH12345678BEIi/BIAEiBDIiSTATiTCMbyte3bits678Status000NosourceTC001InusewithoutIAE010InusewithIAE011,100Reservedforfutureinternationalstandardization101Maintenancesignal:ODUk-LCK110Maintenancesignal:ODUk-OCI111Maintenancesignal:ODUk-AISHow?ODUkTCMACT一個(gè)字節(jié)ODUktandemconnectionmonitoringactivation/deactivationcoordinationprotocolItsdefinitionisforfurtherstudy開銷——ODUk

TCMiOH1234567891011121314234RESTCM3GCC1TCMACTTCM6TCM5TCM4FTFLTCM2TCM1PMEXPGCC2APS/PCCRESHow?ODUkAPS/PCC4個(gè)字節(jié)ODUk自動(dòng)保護(hù)倒換和保護(hù)通訊通道最多含8級(jí)可嵌套的APS/PCC信號(hào)，對(duì)應(yīng)于哪級(jí)連接取決于MFAS線性保護(hù)，ITU-TRec.G.873.1；環(huán)路保護(hù)待研究開銷——ODUkOH1234567891011121314234RESTCM3GCC1TCMACTTCM6TCM5TCM4FTFLTCM2TCM1PMEXPGCC2APS/PCCRESHow?ODUkAPS/PCC開銷——ODUkOH1234567891011121314234RESTCM3GCC1TCMACTTCM6TCM5TCM4FTFLTCM2TCM1PMEXPGCC2APS/PCCRESMFASbits678APS/PCCchannelappliestoconnectionmonitoringlevelProtectionschemeusingtheAPS/PCCchannel(Note)000ODUkPathODUkSNC/N001ODUkTCM1ODUkSNC/S,ODUkSNC/N010ODUkTCM2ODUkSNC/S,ODUkSNC/N011ODUkTCM3ODUkSNC/S,ODUkSNC/N100ODUkTCM4ODUkSNC/S,ODUkSNC/N101ODUkTCM5ODUkSNC/S,ODUkSNC/N110ODUkTCM6ODUkSNC/S,ODUkSNC/N111OTUkSectionODUkSNC/IHow?ODUkFTFL256字節(jié)，每幀占1個(gè)字節(jié)，一個(gè)復(fù)幀傳輸一次傳送失效類型和失效位置信息開銷——ODUkOH1234567891011121314234RESTCM3GCC1TCMACTTCM6TCM5TCM4FTFLTCM2TCM1PMEXPGCC2APS/PCCRESHow?ODUkFTFL開銷——ODUkOH1234567891011121314234RESTCM3GCC1TCMACTTCM6TCM5TCM4FTFLTCM2TCM1PMEXPGCC2APS/PCCRESFTFLmessagestructure012……126127128129130……254255ForwardfieldBackwardfieldForwardfieldstructure01……910……127FaultindicationfieldOperatoridentifierfieldOperatorspecificfieldBackwardfieldstructure128129……137138……255FaultindicationfieldOperatoridentifierfieldOperatorspecificfieldHow?ODUkEXP2個(gè)字節(jié)實(shí)驗(yàn)用，G.709沒定義設(shè)備廠商或網(wǎng)絡(luò)運(yùn)營(yíng)商在自己網(wǎng)絡(luò)內(nèi)部，如需要額外開銷，可以使用ODUkRES保留用，共9個(gè)字節(jié)都置全“0”開銷——ODUkOH1234567891011121314234RESTCM3GCC1TCMACTTCM6TCM5TCM4FTFLTCM2TCM1PMEXPGCC2APS/PCCRESHow?OPUkOH開銷ODUkoverheadareaFASOTUkOH123456789101112131415161234OPUkoverheadMFASMapping&concatenationspecificPSIMapping&concatenationspecific overheadassociatedwithconcatenationandoverheadassociatedwiththemappingofclientsignalsintotheOPUkpayloadPSI payloadstructureidentifier0PT1……255Mapping&concatenationspecificPT payloadtypeHow?OPUkPSI256字節(jié)，每幀占一個(gè)字節(jié)一個(gè)復(fù)幀傳一次傳輸凈荷結(jié)構(gòu)指示(PSI)信號(hào)PSI[0]PT，凈荷類型，一個(gè)字節(jié)，網(wǎng)管一般對(duì)應(yīng)PT失配告警PSI[1]~PSI[255]mappingandconcatenationspecifice