Carrier Ethernet Transport in Metro and Core Networks .ppt

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1、Transport Network,Claus G.Gruber,Achim Autenrieth,claus.gruber,66,Nokia Siemens Networks,2008/09/29,Transport Network,802.1ah Provider Backbone Bridging(PBB)Adding a Transport Hierarchy,802.1adFrame,C-DA6 octets,C-SA6 octets,TP S-TPI S-ID VID D VID2 2 2 2,L/T2,FCS4 octets,User Data46 1500 octets,S-T

2、AG C-TAG,B-TAG,ES-VID,Backbone,ProviderBridgeFrame,B-DA6 octets,B-SA6 octets,TP B-ID VID2 2,L/T2,FCS4 octets,802.1ad Frame(/w or/wo FCS)60 1526 octets,Source:D.Allen,N.Bragg,A.McGuire,A.Reid,Ethernet as Carrier Transport Infrastructure“,IEEECommunications Magazine,Feb.2006 Add a transport hierarchy“

3、MAC in MAC”encapsulation No learning of customer MAC addresses in the middle of the network Transport spanning TREES instead Use global meaning of tag(B-DA(48 bit)and B-VID(12 bit)Networks 2008-Carrier Ethernet Transport in Metro and Core Networks,C-DA,B-DA,Transport Network,Claus G.Gruber,Achim Aut

4、enrieth,claus.gruber,67,Nokia Siemens Networks,2008/09/29,802.1Qay Provider Backbone BridgingTraffic,C-DA,Engineering(PBB-TE)Transparent Tunneling of Ethernet Services B-DATransport Network,802.1adFrame,C-DA6 octets,C-SA6 octets,TP S-TPI S-ID VID D VID2 2 2 2,L/T2,FCS4 octets,User Data46 1500 octets

5、,S-TAG C-TAG,B-TAG,ES-VID,Backbone,ProviderBridgeFrame,B-DA6 octets,B-SA6 octets,TP B-ID VID2 2,L/T2,FCS4 octets,802.1ad Frame(/w or/wo FCS)60 1526 octets,Source:D.Allen,N.Bragg,A.McGuire,A.Reid,Ethernet as Carrier Transport Infrastructure“,IEEECommunications Magazine,Feb.2006 Add a transport hierar

6、chy“MAC in MAC”encapsulation No learning of customer MAC addresses in the middle of the network,Transport PATHS instead,GMPLS or NMS configured,Use global meaning of tag(B-DA(48 bit)and B-VID(12 bit)Networks 2008-Carrier Ethernet Transport in Metro and Core Networks,Claus G.Gruber,Achim Autenrieth,c

7、laus.gruber,68,Nokia Siemens Networks,2008/09/29,802.1Qay Provider Backbone BridgingTraffic,Scalability:,4096 different paths per B-DA Reuse of B-VLAN-ID possible Merging of paths possibleSimplicity:Inherent knowledge of the destination Possibility to have PATHS and(multicast)TREES with theNetworks

8、2008-Carrier Ethernet Transport in Metro and Core Networks,B-DA,B-DA,Engineering(PBB-TE)The Global Label MeaningSameVLAN-ID,B,C,A,Claus G.Gruber,Achim Autenrieth,claus.gruber,69,Nokia Siemens Networks,2008/09/29,Networks 2008-Carrier Ethernet Transport in Metro and Core Networks,802.1Qay Provider Ba

9、ckbone Bridging Traffic Engineering A profile of PBB which allowsengineering deterministic,protected,and secured connection oriented trunks,and servicesMAC learning,xSTP,Broadcast,unknown frames disabledManagement plane is used to set up,Ethernet Switched Paths(ESP),Populates forwarding table Calcul

10、ates load for each ESP andallocates to physical link,Also sets up protecting pathAlternative:control plane signalingTraffic Engineering50ms protection switching(G.8031),PBnw,PBnw,Provider Backbone Bridging network,MAC inMAC,MAC inMAC,Port 1,S-VID 1,C-VID1Port 1,S-VID 1,C-VID2,I-SID 1Port 2I-SID 2Tru

11、nk(B-DA,B-VID),PayloadC-VIDS-VIDSA,DAI-SIDB-VIDB-SAB-DA802.1ah,Claus G.Gruber,Achim Autenrieth,claus.gruber,70,Nokia Siemens Networks,2008/09/29,PBB/PBB-TE SummaryNetworks 2008-Carrier Ethernet Transport in Metro and Core Networks,Claus G.Gruber,Achim Autenrieth,claus.gruber,71,Nokia Siemens Network

12、s,2008/09/29,Contents1.Introduction2.Operator Requirements for Transport Networks3.Ethernet Basics4.Carrier Ethernet Evolution5.Carrier Ethernet Transport Technologies MPLS Basics6.Carrier Ethernet Transport Network Architecture&Solutions7.Outlook Towards Future Internet Architectures8.ConclusionNet

13、works 2008-Carrier Ethernet Transport in Metro and Core Networks,Claus G.Gruber,Achim Autenrieth,claus.gruber,72,Nokia Siemens Networks,2008/09/29,MPLS BasicsTwo AspectsMulti ProtocolMPLS is encapsulating Ethernet,Frame Relay,ATM and IP andtransport them transparently through each networkLabel Switc

14、hingEach packet is marked with a short,fixed-length labelForwarding of packets is based on this labelReservation of resources is associated with this labelNetworks 2008-Carrier Ethernet Transport in Metro and Core Networks,Claus G.Gruber,Achim Autenrieth,claus.gruber,73,Nokia Siemens Networks,2008/0

15、9/29,LERLSR,Non-MPLSaccess networkLabelLSP:SwitchedPathMPLS BackboneNetworks 2008-Carrier Ethernet Transport in Metro and Core Networks,LabelEdgeRouterLabelSwitchingRouter,MPLS BasicsAcronyms,Claus G.Gruber,Achim Autenrieth,claus.gruber,74,Nokia Siemens Networks,2008/09/29,MPLS BasicsShim Header Str

16、ucture,TTL,CoS SIP Packet,Label(20 bits)L2 Header MPLS Header32 bits,MPLS header consist of four fieldsLabelused to associate packet with an LSPExperimental bitscarry packet queuing priority(CoS)Stacking bitTime to livelimits packet lifetime within LSP,In most cases,the IP TTL is copied into the MPL

17、S TTL Some label values are reservedNetworks 2008-Carrier Ethernet Transport in Metro and Core Networks,Claus G.Gruber,Achim Autenrieth,claus.gruber,75,Nokia Siemens Networks,2008/09/29,MPLS Principles“Virtual connections in a connectionless network”Add a label to an IP packet that encodes a predefi

18、ned tunnel,Traffic towards different destinations can be separated or aggregated andforwarded along a pre-defined path using only small labels as“routing”decision Label stacking is possible Efficient Traffic Engineering due to source routing Fast resilience mechanisms,Label EdgeRouter,(LER)Networks

19、2008-Carrier Ethernet Transport in Metro and Core Networks,SwitchRouter(LSR),3:Routingaccording to IPheader,1:The edge routerclassifies packetsand adds an MLPS,header,see tablebelow to them,2:Small tables,fast“routing”Label,IP Packet,Label,IP Packet,Label,Claus G.Gruber,Achim Autenrieth,claus.gruber

20、,76,Nokia Siemens Networks,2008/09/29,MPLS Major Tasks Information distribution(network topology and capacity)Based on existing IP protocols(OSPF,IS-IS,EIGRP)-inband Path calculation What are the best paths?Constraint Based Routing(CBR)Path setup,label distribution and exchange Label Distribution Pr

21、otocol(LDP)Reservation Protocol(RSVP-TE)Forwarding of traffic along the MPLS pathNetworks 2008-Carrier Ethernet Transport in Metro and Core Networks,Claus G.Gruber,Achim Autenrieth,claus.gruber,77,Nokia Siemens Networks,2008/09/29,Label EdgeRouter(LER),4:Routing according to IPheader,In LabelANetwor

22、ks 2008-Carrier Ethernet Transport in Metro and Core Networks,Out LabelC,1:The edge router classifiespackets and adds an MLPS,header to them(see table below)Label SwitchRouter(LSR),Forwarding Principle3:Last but one router drops,the MPLS header,Addressprefix129.187.0.0/16185.222.0.0/16,Next HopIP Ad

23、dress102.4.4.2102.4.4.3,Address,prefix129.187.0.0/16185.222.0.0/16,Next Hop,IP Address10.152.4.210.152.4.2,Out,LabelAA,2:Forwarding using labelsinstead of IP addresses-,Swapping of labels at eachintermediate router,Router(LSR),Claus G.Gruber,Achim Autenrieth,claus.gruber,78,Nokia Siemens Networks,20

24、08/09/29,Path Setup with RSVP The Ingress LSR(I-LSR)sends a PATH message along the calculatedroute(source routing).Each intermediate router checks if the required bandwidth is available andforwards the message to the tail of the path(last router).The Egress LSR(E-LSR)sends a RESV message back along

25、the samepath.On the way back,the resources are reserved and labels are selectedand signaled to the upstream LSR Paths are updated/refreshed via a“soft-state mechanisms”,E-LSR,I-LSR,PATH messageRESV messageNetworks 2008-Carrier Ethernet Transport in Metro and Core Networks,Claus G.Gruber,Achim Autenr

26、ieth,claus.gruber,79,Nokia Siemens Networks,2008/09/29,Networks 2008-Carrier Ethernet Transport in Metro and Core Networks,Pros and Cons of MPLS Switching,Advantages:+Aggregation of traffic+Reduction of routing entries+Efficient traffic engineeringpossibilities(source routing)+Fast and efficient res

27、iliencemechanisms+VPN support+GMPLS support,Disadvantages:-Additional technology belowthe IP Layer-Handling of MPLS paths(number,soft state)-Complexity of NetworkConfiguration-Tight interelation of IP andMPLS makes it quite complexto handle,Claus G.Gruber,Achim Autenrieth,claus.gruber,80,Nokia Sieme

28、ns Networks,2008/09/29,Transport teams mentalityLong term statically provisionedpaths,pre-determined backup pathsHighly automated operationenvironmentStrong reliance on automated OAMand fault management systemsSimple static control plane scoreswell over complex dynamic control,planeNetworks 2008-Car

29、rier Ethernet Transport in Metro and Core Networks,Transport teams view on IP/MPLSBelieve IP/MPLS is not suitable fortransport applicationsConsider it to be very complex(LDP,IS-IS,OSPF,MPLS-TE,CSPF,FRR,.)Do not need dynamic routing protocols,and recovery times too slowIP/MPLS OAM tools not consisten

30、t withtransport OAM requirements,Challenge:Is MPLS ready to replace SDH/SONET?Carrier Ethernet will replace SDH/SONET infrastructure over timeSONET/SDH infrastructure traditionally designed and managed by transportdepartments,Claus G.Gruber,Achim Autenrieth,claus.gruber,81,Nokia Siemens Networks,200

31、8/09/29,Contents1.Introduction2.Operator Requirements for Transport Networks3.Ethernet Basics4.Carrier Ethernet Evolution5.Carrier Ethernet Transport Technologies T-MPLS6.Carrier Ethernet Transport Network Architecture&Solutions7.Outlook Towards Future Internet Architectures8.ConclusionNetworks 2008

32、-Carrier Ethernet Transport in Metro and Core Networks,Claus G.Gruber,Achim Autenrieth,claus.gruber,82,Nokia Siemens Networks,2008/09/29,Networks 2008-Carrier Ethernet Transport in Metro and Core Networks,DA6 octets,SA6 octets,TP S-TPI S-ID VID D VID2 2 2 2,L/T2,FCS4 octets,User Data46 1500 octets,S

33、-TAG,T-MPLS(Transport Multi Protocol Label Switching)Idea:Use the MPLS concept known from IP and adapt it for forwarding issuesdefined in ITU-T G8110.1 Operate independently of its clients and its associated control networks(Management and Signaling Network).“IP/MPLS IP+SDH”MPLS with a few changes:U

34、se of Penultimate Hop Popping is prohibited Uni-directional and bi-directional LSPs can be defined Use of global or per interface label space Three types of Signalling Communication Channels(in-band via native IPpackets,in-band via dedicated LSP,out-of band)OAM based on Y.1711 and Y.1731 Protection

35、switching(ITU-T Y.1720)Merging and ECMP is prohibited Multicasting in alignment to on-going work in IETF C-TAG,T-MPLS,GFP or Ethernet,Claus G.Gruber,Achim Autenrieth,claus.gruber,83,Nokia Siemens Networks,2008/09/29,Contents1.Introduction2.Operator Requirements for Transport Networks3.Ethernet Basic

36、s4.Carrier Ethernet Evolution5.Carrier Ethernet Transport Technologies MPLS-TP6.Carrier Ethernet Transport Network Architecture&Solutions7.Outlook Towards Future Internet Architectures8.ConclusionNetworks 2008-Carrier Ethernet Transport in Metro and Core Networks,Claus G.Gruber,Achim Autenrieth,clau

37、s.gruber,84,Nokia Siemens Networks,2008/09/29,MPLS-TP standardization process and timelineMPLS-TPTimeline:ITU-T-IETF Joint Working Team(JWT),was setup in March 2008,Agreement reached onrecommendations:End of April 2008First draft:July 2008Expected final agreements:E 2009Networks 2008-Carrier Etherne

38、t Transport in Metro and Core Networks,Joint Working Team,Claus G.Gruber,Achim Autenrieth,claus.gruber,85,Nokia Siemens Networks,2008/09/29,Technologies comparisonNetworks 2008-Carrier Ethernet Transport in Metro and Core Networks,In standardization process,Claus G.Gruber,Achim Autenrieth,claus.grub

39、er,86,Nokia Siemens Networks,2008/09/29,Market shift from PBB-TE to MPLS-TP,NSN focus,Mature but not transport oriented,IP/MPLS,T-MPLSELSPBB-TE,T-MPLSBased on MPLS maturityEnhanced for Transport,MPLS-TP,The options,Transport orientedTerminated by ITU-TStandardized partly(single tagging)Double use of

40、 VID for user-trafficseparation and routingIn standardization processNot matureNo Control plane,No multipoint supportMPLS-TP MPLS Transport ProfileIP/MPLS&L2 MPLS can be categories as IETF MPLSNetworks 2008-Carrier Ethernet Transport in Metro and Core Networks,Claus G.Gruber,Achim Autenrieth,claus.g

41、ruber,87,Nokia Siemens Networks,2008/09/29,Nokia Siemens Networks is a major player in MPLS-TP standardization,MPLS,Connection Oriented Lacks sometransportcapabilities,T-MPLS,A subset of MPLS plus additionalcapabilities providing packet transport Uses the same Ether type as MPLS butsome mechanisms a

42、re not compatiblewith MPLS,Nokia Siemens Networks has participants in the Joint Working TeamNokia Siemens Networks acts as author and co-author forrequirements,framework and solution documents,JWT,3.Frameworks3.1 MPLS-TP3.2 3.3 OAM3.4 Survivability3.4.1 for LSPs3.4.2 for PWs3.6 Control Plane3.7 Netw

43、orkManagement,2.Requirements2.1 MPLS-TP2.2 OAM2.3 Networkmanagement,4.Solution Documents4.1 Generic ACH Alert Label Definition4.2 ACH definition4.3 OAM Procedure document4.3.1 OAM Analysis document4.3.2 OAM Tool documents4.4 Survivability4.4.1 Linear Protection4.4.2 Ring Protection,4.5 Control Plane

44、 protocolsNetworks 2008-Carrier Ethernet Transport in Metro and Core Networks,Claus G.Gruber,Achim Autenrieth,claus.gruber,88,Nokia Siemens Networks,2008/09/29,Networks 2008-Carrier Ethernet Transport in Metro and Core Networks,What is MPLS-TP?A new standard focused on extending MPLS as a viable tra

45、nsportoption to help building the next generation packet transport networkBeing developed by IETF as a result of a collaboration between IETF and ITU-T via jointworking team(JWT)Objective:To bring transport requirements into IETF MPLS and extend IETF MPLSforwarding,OAM survivability,network manageme

46、nt and control planeprotocols to meet those requirements through IETF standard processThe JWT is divided into multiple sub-groups focused on:,Forwarding planeOAM,ProtectionControl plane,Management,Claus G.Gruber,Achim Autenrieth,claus.gruber,89,Nokia Siemens Networks,2008/09/29,MPLS-TP foundationThe

47、 architecture for a transport profile of MPLS(MPLS-TP)is based on IETF MPLS(RFC 3031)&IETF PWE3(RFC 3985)Networks 2008-Carrier Ethernet Transport in Metro and Core Networks,OAMextensionsControl Planeextensions,ManagementextensionsAlert LabelDefinitionextensions,MPLS-TP profileSurvivabilityextensions

48、,MPLS-TP defines a profile of MPLS targeted at Transport applications.This addresses specific MPLS characteristics and extensionsrequired to meet transport requirements.,Claus G.Gruber,Achim Autenrieth,claus.gruber,90,Nokia Siemens Networks,2008/09/29,Networks 2008-Carrier Ethernet Transport in Metr

49、o and Core Networks,Desire:To make MPLS more Transport Oriented,Control plane:Data plane:,Optional and separated from data planeData,OAM,protection congruent within architecture,MPLS-TP,NMS Point&ClickLSP and PWEmanagement via externalLSP,PWE,OAMworks independent of controlplane,Configuration ofLSPs

50、&PWEs via NMSand later dynamic controlplaneOAM and Data pathmust be congruent(usethe same path),LSPs,PWEsnesting similar toSONET/SDHenvironmentsProtection and OAMmechanism workswithin the MPLS,architectureManagement plane:Configuration of LSP,PWE with point&click,Claus G.Gruber,Achim Autenrieth,clau