Core Network Connects MAN networks together Requires high - PowerPoint PPT Presentation

Lic.(Tech.) Marko Luoma (1/37) Lic.(Tech.) Marko Luoma (2/37) Core Network Connects MAN networks together � Requires high bandwidth technologies with long range passive operation � � Transmission speed and distance without repeaters tend to be S-38.192 Verkkopalvelujen tuotanto inversely proportional S-38.192 Network Service Provisioning � 1Gbps Ethernet -> 80-150km in SM-fiber with ZX-transmitter � 10Gbps Ethernet -> 10-40km in SM-fiber with ZX-transmitter Lecture 2: Core Network Technologies Typical medias are � � Fiber (Single Mode) � Radio (Microwave, Satellite) Lic.(Tech.) Marko Luoma (3/37) Lic.(Tech.) Marko Luoma (4/37) Core Network Technologies IP IEEE 802.2 LLC IEEE 802.2 LLC PPP AAL5 RPR MAC Ethernet MAC HDLC ATM High bandwidth requirements Frame based multiplexing � � � Irrespective of low layer Transmission speeds are jumping 10Gbps Eth 10 Gbps Eth Gbps Eth � RPR PHY LAN PHY WAN PHY PHY PoS up with constant rate functionality EoS VC-64c � Fiber/Radio � 1995: 155Mbps (SDH/ATM) GFP � Options today are � 2000: 2.4Gps (SDH) � GMPLS � 2004: 10 Gbps SDH (SDH/Ethernet) � SDH G.709 OCh Digital framing / wavelength multiplexing � 2000-2004 wavelength � ATM DWDM technologies brought a new � Ethernet means to increase capacity Dark fiber / fiber network � GFP � DWDM EoS Ethernet over SDH (Proprietary) RPR Resilient Packet Rings (IEEE 802.17) PoS Packet over SDH GFP Generic Framing Procedure � CWDM

Lic.(Tech.) Marko Luoma (5/37) Lic.(Tech.) Marko Luoma (6/37) WDM WDM Optical counterpart for Frequency Division Multiplexing � Effectively N fold increase of transmission capacity from the same fiber � infrastructure � Wide band components are relatively more expensive than N times FDM WDM narrow band components � Individual lambdas can be used independently � Usage depends on transponder unit � Framing is in general from SDH (interface may be what ever) � STM-16 – 2.4Gbps � STM-64 – 10 Gbps = 10GbE Frequency Wavelength � STM-256 – 40 Gbps = 40GbE Carrier Lic.(Tech.) Marko Luoma (7/37) Lic.(Tech.) Marko Luoma (8/37) WDM WDM Two operative versions � DWDM CWDM � � � CWDM – Coarse Wavelength Division Multiplexing � Narrow channel � Wide channel � Max 8 channels between (1470 - 1610nm with 20nm steps) � Components need to be � Component requirements � DWDM – Dense Wavelength Division Multiplexing compensated for are looser temperature effects � ITU Grid (100 Ghz resolution) � Cheaper lasers and � Expensive receivers � 50 channels between 1569.80nm to 1611.79nn � 50 channels between 1529.75nm to 1569.59nm � More channels to choose � Less channels from � 50 channels between 1491.69nm to 1529.55nm � Not suitable for long-haul � nonlinearities of fibers can networks be avoided by selecting � Suitable for MANs proper wavelengths

Lic.(Tech.) Marko Luoma (9/37) Lic.(Tech.) Marko Luoma (10/37) WDM WDM Can be used as link or network technology � Pros: � � Link technology � Protocol independent � Multiplexers at the ends of the links � Virtual fiber � Network technology � Multiplexing different traffic through different wavelengths � Optical switching components � Similar failure protection than SDH networks (SDH framing) � Optical delay lines Cons: � � Wavelength conversion � Depending on system pay as you go may not be possible � Photonic switching � The number of required channels need to be estimated for lifetime of systems � Not cost effective if capacity expansion is not immediately required Lic.(Tech.) Marko Luoma (11/37) Lic.(Tech.) Marko Luoma (12/37) Frame Multiplexing Frame Multiplexing � Synchronous � Asynchronous B C � Fixed usage of resources � Free usage of resources A C A B D � Information does not need � Information requires L2 A D A B C D L2 addresses addresses � Wastes resources if � Does not waste resources Synchronous multiplexing communication is not CBR � Requires additional logics to � Fixed usage of resources � Easy to integrate control resource usage D C B A D C B A D C B A D C B A D C B A � SDH � ATM, Ethernet Asynchronous multiplexing � Free usage of resources C B C A D B A D A D C B A

Lic.(Tech.) Marko Luoma (13/37) Lic.(Tech.) Marko Luoma (14/37) SDH SDH Synchronous frame based multiplexing of transmitted signals Link frames contain virtual containers which carry the actual � � information � Link framing is done with 2430 byte frames � Header information (POH) � Generation interval is 125us -> reflects the original coding of � Flow and error control information between edge devices speech with 8kHz sampling rate � Datarate = 155,52Mbps � Content � Virtual containers form point-to-point permanent connections 1 2 3 4 5 6 7 8 9 10 11 ? 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 ? 534 535 536 537 538 539 540 through SDH network 541 542 ? 809 810 811 812 ? 1079 1080 1081 1082 ? 1349 1350 P 1351 1352 ? 1619 1620 Content O 1621 1622 ? 1889 1890 H 1891 1892 ? 2159 2160 2161 2162 ? 2429 2430 SOH (9-tavua) VC-4 (261-tavua) Lic.(Tech.) Marko Luoma (15/37) Lic.(Tech.) Marko Luoma (16/37) SDH SDH SDH hierarchy makes possible to use multiples and fractions of basic Fractions are generated by multiplexing different streams of content into � � individual frame rate � Several virtual containers destined to same or different points in � Multiples are generated by injecting multiple (factor of four) link network frames within time-slot *N � STM-1: 155.52 Mbit/s (basic rate) STM-N AUG AU-4 VC-4 C-4 140M � Multiplexing is done � STM-4: 622.08 Mbit/s (first multiplex) *3 with byte interleaving � STM-16: 2488.32 Mbit/s (second multiplex) 45M TUG-3 TU-3 VC-3 C-3 34M � STM-64: 9953.28 Mbit/s (third multiplex) Osoittimien käsittely Multipleksaus *7 � Operation is byte synchronous Vaiheistus � Timing of individual bytes in multiplex Mapitus TUG-2 TU-2 VC-2 C-2 6M is same than in basic rate frame *3 TU-12 VC-12 C-12 2M 1 1 1 1 2 2 2 2 3 3 3 3 4 4 4 4 ? 2429 2430 2430 2430 2430

Lic.(Tech.) Marko Luoma (17/37) Lic.(Tech.) Marko Luoma (18/37) SDH SDH SDH supports also concatenation of resources Terminal multiplexer � � � Old version – strict mode � Responsible of taking non- SDH and lower rate SDH � Clear channel operation (small 'c' after the virtual container type) traffic in and interleave them � All VC:s in different frames form a single bit stream in STM-N frames. A � Not feasible in SDH networks � Vice versa on other end of the STM-N � Feasible if SDH is used as a point to point link technology path � New version – flexible mode � Each incoming traffic � Concatenation is used only in edge devices component has its own virtual K container (routed separately � Supports SDH networks within SDH network) � Concatenated VC:s need not be with same speeds � Even over different fibers Lic.(Tech.) Marko Luoma (19/37) Lic.(Tech.) Marko Luoma (20/37) SDH SDH Add-drop multiplexer Digital Cross Connect � � � Basic component in ring type � Switches SDH traffic SDH networks � Between fibers � Most of traffic passes � From individual STM through the ADM on ring frame to other interfaces � Basic component on mesh � Some traffic is taken out of type networks ring and/or inserted into the ring

Lic.(Tech.) Marko Luoma (21/37) Lic.(Tech.) Marko Luoma (22/37) SDH SDH IP can not be used directly with SDH Pros: � � � Packet over Sonet (PoS) is method for delivering IP packets in SDH � Optimized for TDM services (large income from leased line services) � Additional framing � Fully compatible with metro ring networks (SDH ADM rings) IP packet � IP packet into PPP-packet � Reliable and fast failure recovery (roughly 50ms with APS) � PPP packet into HDLC frame � Price of SDH continuously coming down � HDLC frame into SDH Protocol PPP-Data Padding Cons: � virtual container � Not cost effective for burst data traffic � Capacity in SDH network can only be allocated on multiples of Address Control FCS 0x7E HDLC-Data 0x7E (0xFF) (0x03) (CRC-32) 2Mbps N x HDLC frame � No multiple QoSs for different service charges � Expensive interfaces at routers HEADER VC-x data Lic.(Tech.) Marko Luoma (23/37) Lic.(Tech.) Marko Luoma (24/37) ATM ATM Asynchronous frame based multiplexing Header fields define � � Capabilities for dynamic switching � Connection � VPI VPI � Not only PVP's or PVC's VPI VCI � Multiplexing group VPI VCI VCI VCI Connection oriented � VCI PT CLP VCI PT CLP Fixed packet structure � HEC HEC VC � 5 bytes of headers VP MEDIA � Addresses (VPI, VCI) � Packet content type (PT) DATA DATA � Priority (CLP) � Checksum (HEC) � 48 bytes of data