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PMC-SIERRA High-Speed Ethernet WAN Connectivity through the Public Network Steven Gorshe, Ph.D. Principal Engineer Product Research PMC-Sierra, Inc. steve_gorshe@pmc-sierra.com 1 2004 Presentation to the Oregon IEEE Section Outline Introduction Types of Ethernet WAN services - Private Line and LAN - Virtual Private Line and LAN PMC-SIERRA Who’s who in the standards world Enabling technologies in the transport network - VCAT, LCAS, and GFP for SONET/SDH and PDH systems - Resilient Packet Ring (IEEE 802.17 RPR) - MPLS Conclusions 2 2004 Presentation to the Oregon IEEE Section PMC-SIERRA Introduction 3 2004 Presentation to the Oregon IEEE Section Why Ethernet transport? PMC-SIERRA >90% of WAN data traffic is terminated on an Ethernet at one or both ends of the WAN - Users perceive Ethernet as inexpensive and easy to use, and enterprise administrators are already familiar with it Logical high-speed replacement for Frame Relay and ATM Many carriers and equipment vendors see Ethernet transport as the most likely candidate for new revenue-making services. - Has potential provisioning and operational cost savings for the carriers. 4 2004 Presentation to the Oregon IEEE Section Why over existing transport networks? Existing core network is SONET/SDH (or PDH) PMC-SIERRA - Enormous sunk capital investment - The Operations, Administration, Maintenance and Provisioning (OAM&P) overhead is necessary to reduce the cost of providing the network. Keeping a separation between Layer 1 transport services and higher layers is desirable and for some carriers necessary. Hence, there is a strong desire to provide Ethernet transport over SONET/SDH/PDH rather than as a native Ethernet signal. 5 2004 Presentation to the Oregon IEEE Section PMC-SIERRA Types of Ethernet WAN Services 6 2004 Presentation to the Oregon IEEE Section Types of Ethernet Transport Topologies Ethernet Private Line (EPL) - Point-to-point, leased-line service PMC-SIERRA Ethernet Private LAN (EPLAN) - Multi-point service over leased lines Ethernet Virtual Private Line (EVPL) - Point-to-point service over shared resources Ethernet Virtual Private LAN (EVPLAN) - Multi-point service over shared resource 7 2004 Presentation to the Oregon IEEE Section General Network View demarc PMC-SIERRA NNI demarc UNI-C Customer Transport UNI-N Transport Operator Operator s AÕ s AÕ Network Network UNI Attributes Access Transport Transport UNI-N Operator Operator s BÕ s BÕ Network Network UNI-C Customer Ethernet Connection Attributes UNI-N to UNI-N UNI-C to UNI-C NNI Attributes Access ETH ETH FD Operator FD Operator FD From G.8011 FD ETY Operator FD Operator FD ETY 8 2004 Presentation to the Oregon IEEE Section SONET/SDH Physical Transport Layer for Ethernet transport Service Provider GbE/FX PMC-SIERRA Physical Layer STM-n STM-n FE/FX STM-n STM-n FE/FX FE/FX FE/FX FE/FX Interoffice Feeder Distribution 9 2004 Presentation to the Oregon IEEE Section Packet switching sub-layer overlay for Ethernet Transport Service Provider Vc-4-nv GbE/FX VC4nv - Packet Ring VC-n PMC-SIERRA Packet switching sub-layer VC-n FE/FX Layer 1 - Physical STM-n STM-n STM-n FE/FX STM-n FE/FX FE/FX Interoffice Packet Ring Feeder Packet Distribution Adaptation Service Port 10 2004 Presentation to the Oregon IEEE Section Layered Architecture for EPL services Service Provider PMC-SIERRA p-t-p Connectivity Services SLS= 20Mb/s SLS=BE Broadband Access Service SLS=15Mb/s overbooked VCn Vc4nv VC4nv - Packet Ring VCn Layer 1 - Physical STM-n STM-n STM-n STM-n Interoffice Packet Ring Feeder Packet Distribution Adaptation Service Port 11 2004 Presentation to the Oregon IEEE Section Services Characterized by Ethernet Connection Attributes (G.8011) EC service attribute Network connectivity Transfer characteristics Point-to-point, point-to-multipoint, multipoint-to-multipoint Address (deliver conditionally or unconditionally) PMC-SIERRA Service attribute parameters and values Drop Precedence (drop randomly, drop conditionally, or N.A.) Class of Service Customer Spatial or logical Separation Link type Connectivity monitoring Bandwidth profile UNI list Service instance Dedicated or shared Sub-layer monitoring: On demand, proactive, none Inherent monitoring: Proactive Specified Arbitrary text string to uniquely identify the UNIs associated with the EC VLAN ID (yes or no) Preservation Survivability 12 2004 Class of Service (yes or no) None, or server-specific Presentation to the Oregon IEEE Section EPL Type 1 PMC-SIERRA Ethernet PHY Customer Equipment SONET/SDH, DSn/PDH, or OTN Carrier Network Ethernet PHY Carrier Equipment Customer Equipment Carrier Equipment Carrier Network Customer Equipment ETH Access Link ETH Trunk Link ETH Access Link Customer Network 13 2004 Presentation to the Oregon IEEE Section EPL Type 2 PMC-SIERRA CI=8B/10B symbol stream Customer Equipment 802.3 SDH VC-4-7v 802.3 Customer Equipment Carrier Equipment Carrier Network Carrier Equipment • Interface rate is 1.25Gb/s: PhIR = 1 Gbit/s ± 100 ppm • Customer service rate is 1.00Gb/s: CSR • SDH connection bandwidth is VC-4-7v: NRoS = 1 048 320 kbit/s ± 4.6 ppm • Protection optionally provided by network • Mapping is GFP-T 14 2004 Presentation to the Oregon IEEE Section EPL Ethernet Connection Attributes (G.8011.1) EC service attribute Network connectivity Transfer characteristics Point-to-point Address (deliver unconditionally) Drop Precedence – Not Applicable Class of Service Customer Separation Link type Connectivity monitoring Bandwidth profile UNI list Service instance Dedicated None, on-demand, or proactive PMC-SIERRA Service attribute parameters and values Spatial or logical – Always connection oriented Committed information rate (CIR) and committee burst size (CBS) Arbitrary text string to uniquely identify the UNIs associated with the EC VLAN ID is preserved Preservation Survivability 15 2004 Class of Service is preserved None, or server-specific Presentation to the Oregon IEEE Section EVPL Ethernet PHY Customer A Equipment PMC-SIERRA SONET/SDH or OTN Ethernet PHY Customer A Equipment Carrier Network Customer B Equipment Carrier Equipment Carrier Equipment Customer B Equipment Two circuit illustration of EVPL Ethernet PHY Customer A Equipment SONET/SDH or OTN Ethernet PHY Customer A Equipment Carrier Network Customer B Equipment Carrier Equipment Carrier Equipment Customer B Equipment In contrast, two circuits with EPL 16 2004 Presentation to the Oregon IEEE Section EVPL Ethernet Connection Attributes (expected) EC service attribute Network connectivity Transfer characteristics Point-to-point Address (deliver conditionally or unconditionally) PMC-SIERRA Service attribute parameters and values Drop Precedence (drop randomly, drop conditionally, or not applicable) Class of Service Customer Logical Separation Link type Connectivity monitoring Bandwidth profile UNI list Service instance Shared None, on-demand, or proactive Specified Arbitrary text string to uniquely identify the UNIs associated with the EC VLAN ID (yes or no) Preservation Survivability 17 2004 Class of Service (yes or no) None, or server-specific Presentation to the Oregon IEEE Section Some EVPL Open Issues PMC-SIERRA How do you specify the client data rates at the network endpoints and in the middle (i.e., the shared portion) of the network. - Service Level Agreement (SLA) definitions How are the different client streams tagged? VLAN Tags (IEEE 802.1q with stacking) MPLS Enhanced GFP (with new Extension header) ATM Ethernet MAC-in-MAC RPR 18 2004 Presentation to the Oregon IEEE Section EPLAN and EVPLAN CI = (un)tagged MAC frame stream Carrier Equipment Customer Equipment 802.3 Carrier Network DS1, DS3, SONET VT, STS-1, STS-Nc, OTN ODUk or virtually concatenated multiples of them 802.3 PMC-SIERRA Customer Equipment Customer Equipment 802.3 802.3 Customer Equipment Customer Equipment 802.3 802.3 Customer Equipment PIR ≥CIR ΣPIR ≥NRoS STS-12 shared between 3 flows 19 2004 Presentation to the Oregon IEEE Section EPLAN and EVPLAN – 3 connectivity examples Ethernet PHY Customer Equipment SONET/SDH or OTN Carrier Network PMC-SIERRA Ethernet PHY Customer Equipment SONET/SDH or OTN Ethernet PHY Customer Equipment Ethernet PHY Customer Equipment Ethernet PHY Customer Equipment Ethernet PHY Customer Equipment Carrier Network Mesh connectivity Ethernet PHY Customer Equipment SONET/SDH or OTN Carrier Network Traffic hauled to centralized switching point(s) Ethernet PHY Customer Equipment Ethernet PHY Customer Equipment Switching at network edge (hub and spoke) 20 2004 Presentation to the Oregon IEEE Section EVPLAN Ethernet Connection Attributes (anticipated) EC service attribute Network connectivity Transfer characteristics Multipoint-to-multipoint (and probably point-to-multipoint) Address (deliver conditionally or unconditionally) PMC-SIERRA Service attribute parameters and values Drop Precedence (drop randomly, drop conditionally, or N.A.) Class of Service Customer Logical Separation Link type Connectivity monitoring Bandwidth profile UNI list Service instance Shared None, on-demand, or proactive Specified Arbitrary text string to uniquely identify the UNIs associated with the EC VLAN ID (yes or no) Preservation Survivability 21 2004 Class of Service (yes or no) None, or server-specific Presentation to the Oregon IEEE Section Some EVPLAN Open Issues PMC-SIERRA All of the EVPL issues magnified due to the number of different ports on the EVPLAN - How do you specify rates and reserve bandwidth when multiple ports may be simultaneously sending data to the same egress port? - Tag field size becomes especially important here. 22 2004 Presentation to the Oregon IEEE Section Network example of EVPL and EVPLAN CE PMC-SIERRA P1 P3 CE CE P1 P3 P2 P1 P2 CE CE P1 P3 P2 P2 P3 P3 P3 P4 P4 P2 CE P1 CE P2 Ethernet over Transport Network Ethernet Virtual Private Line Ethernet Virtual Private LAN P1 CE 23 2004 Presentation to the Oregon IEEE Section Application examples Enterprise HQ PMC-SIERRA 1 Multiple flows aggregation <(n1+n2+n3)×VT1.5 2 MxU Multiple flows aggregation VC3 Access Access n1×VT1.5 Core Enterprise Branch Site n3×VT1.5 Core Supplier Site n2×VT1.5 ISP A ISP B Business Partner Site ISP C Hub and spoke for a single customer Aggregation of flows from multiple customers 24 2004 Presentation to the Oregon IEEE Section Application examples (continued) CO Multiple flows aggregation VC3 PMC-SIERRA 3 VC3 Core EO VC3 VC3 EO EO DSLAM uplink aggregation This application could become very important as DSLAMs move from being ATM-based to IP-based 25 2004 Presentation to the Oregon IEEE Section PMC-SIERRA Standards 26 2004 Presentation to the Oregon IEEE Section The Standards Who’s Who (Summary) PMC-SIERRA IEEE - Ethernet Operations Administration and Management (OAM) - Various new MAN/WAN technologies ITU-T SG15 - The transport network standards used by the carriers - Adaptation into the transport network, including encapsulation - NNI specifications ITU-T SG13 - OAM and protection switching standards used by the carriers Metro Ethernet Forum (MEF) - Service models, architectures, and service definitions - UNI and NNI definitions - Traffic management and OAM flows IETF - Ethernet transport using IETF protocols 27 2004 Presentation to the Oregon IEEE Section Standards activities - IEEE Organization IEEE 802.3ae 10 Gbit Ethernet, which included a WAN PHY interface to simplify interfacing to a SONET/SDH or G.709 OTN network Resilient Packet Rings: Working on a ring-based network for access and metro applications Ethernet in the First Mile, where work includes OAM aspects for Ethernet Links, specially access links Provider Bridge specification – This is the Q-in-Q standard. Connectivity Fault Management , or Ethernet Service OAM MAC Security (MacSec), including authentication, authorization and encryption Activities PMC-SIERRA Status Approved 802.17 (RPR) 802.3ah (EFM) 802.1 ad Approval Approved In Progress 802.1ag In Progress 802.1ae In progress 28 2004 Presentation to the Oregon IEEE Section Standards activities – ITU-T SG15 G.8011.1 (Q12) G.8012 (Q11) G.8010 (Q12) Ethernet Private line serice PMC-SIERRA ITU-T SG15 (International Telecommunications Union – Telecommunications Standardization Sector, Study Group 15) [With input from ANSI/ATIS T1X1] Approved 2004. Approved 2004. Approved 2003 Ethernet UNI and Ethernet Transport NNI Ethernet Layer Network Architecture, which is largely to translate the IEEE 802 network material into ITU-T transport network terminology and models Ethernet over Transport – Ethernet Service Characteristics Ethernet over Transport – Ethernet Service Multiplexing, which will cover the multiplexing protocol(s) required to implement EVPL and EVPLAN Characteristics of Ethernet transport network equipment functional blocks G.8011 (Q12) G.esm (Q12) Approved 2004 Approval targeted for. 2004 Approved 2004 (focus on EPL portion) G.8021 (Q9) Q2 Studying Ethernet OAM aspects relating to access In progress 29 2004 Presentation to the Oregon IEEE Section Standards activities – Metro Ethernet Forum Metro Ethernet Forum (MEF) MEF1 MEF2 MEF3 MEF4 MEF5 UNI Type 1 UNI Type 2 EMS-NMS MEF Architecture part 2 CES PDH Ethernet Services Model, Phase 1 Requirements and Framework for Ethernet Service Protection in Metro Ethernet Networks Circuit Emulation Service Definitions, Framework and Requirements in Metro Ethernet Networks Metro Ethernet Network Architecture Framework - Part 1: Generic Framework Traffic Management Specification: Phase I Specification of UNI, data-plane aspects Specification of UNI, control-plane aspects (ELMI) MIBS for Ethernet and network management Specifies functional elements of Ethernet trail, such as adaptation, conditioning, etc. Implementation agreement of PDH CES over Ethernet. Includes both AAL1 and Raw method PMC-SIERRA Approved Approved Approved Approved Approved In progress In progress In progress In progress In progress 30 2004 Presentation to the Oregon IEEE Section Standards activities - IETF PMC-SIERRA Internet Engineering Task Force (IETF) PWE3 WG Working on defining an Ethernet transport over IP/MPLS using Martini drafts. This is mainly EVPL service using UDP, L2TP or MPLS as multiplexing layer Requirements for Virtual Private LAN Services (VPLS) In progress PPVPN WG In progress L2VPN WG Working on framework and service requirements of Ethernet-based VPN, and defining EVPLAN service using IP/MPLS. In progress 31 2004 Presentation to the Oregon IEEE Section PMC-SIERRA Enabling Technologies in the Transport Network (from ITU-T SG15, IEEE & IETF) 32 2004 Presentation to the Oregon IEEE Section Virtual Concatenation (VCAT) PMC-SIERRA Motive for VCAT was to efficiently accommodate data and video signals - Existing channel sizes were a very poor match in most cases - Critically important to build new services on the ubiquitous SONET/SDH backbone network rather than deploying new, overlay networks. Allows independent routing of constituent members Transparent to intermediate nodes. Differential delay compensation is integrated into the protocol in the SONET overhead (i.e. at Layer 1). Essentially an inverse multiplexing technique. Independence of members greatly simplifies routing and management. VCAT capability was recently added to DS1, DS3, E1, and E3 signals 33 2004 Presentation to the Oregon IEEE Section Virtual Concatenation Illustration Frames launched in-phase from the VCAT source SQ=0 SQ=1 SQ=2 SQ=3 SQ=4 DCS SQ=0 SQ=1 SQ=0 SQ=1 SQ=2 SQ=3 SQ=4 DCS SQ=3 SQ=4 SQ=2 SQ=3 SQ=4 DCS SQ=2 SQ=0 SQ=1 SQ=3 SQ=4 DCS RING ADM SQ=0, SQ=4 RING ADM SQ=4 Frames arrive out of phase at the sink due to different paths SQ=0 SQ=1 SQ=2 SQ=3 After sink differential delay compensation SQ=0 SQ=1 SQ=2 SQ=3 SQ=4 PMC-SIERRA VCAT PTE SQ=0 SQ=1 SQ=3 SQ=4 RING ADM RING ADM RING ADM RING ADM VCAT PTE SQ=3, SQ=1, SQ=2 Differential delay compensation required at sink 34 2004 Presentation to the Oregon IEEE Section Virtual Concatenation Example STS-1 #1, GID-a, SQ#=0 STS-1 #2, GID-a, SQ#=1 Client Signal A STS-1 #3, GID-a, SQ#=2 Client Signal B Client Signal C Client Signal D STS-1 #4 STS-1 #5 STS-1 #6 STS-1 #7, GID-a, SQ#=3 STS-1 #8, GID-b, SQ#=0 Client Signal E STS-1 #9, GID-b, SQ#=1 STS-1 #10, GID-b, SQ#=2 STS-1 #11 STS-1 #12 PMC-SIERRA Two VC groups - Note: GID = Group ID, SQ = Sequence number 35 2004 Presentation to the Oregon IEEE Section Link Capacity Adjustment Scheme (LCAS) PMC-SIERRA A handshake mechanism for dynamically adjusting the size of a Virtually Concatenated channel - Allows TDM servers more flexibility for handling dynamic bandwidth demands and Layer 1 - Relies on the NMS/EMS (Control Plane) to provision the bandwidth change - Allows channel size adjustment to be hitless (rather than breaking the connection during the channel size change). - Provides automatic service restoration capabilities - Protocol defined in ITU-T G.7042 Currently defined for SONET/SDH, PDH, and G.709 OTN - SONET STS and VT, DS1, DS3, E1, E3, OTN ODUk 36 2004 Presentation to the Oregon IEEE Section LCAS Example – Adding to a Channel (Part 1) STS-1 #1, GID-a, SQ#=0, CTRL=NORM STS-1 #2, GID-a, SQ#=1, CTRL=NORM Client Signal A PMC-SIERRA STS-1 #3, GID-a, SQ#=2, CTRL=NORM Client Signal B Client Signal C Client Signal D STS-1 #4 STS-1 #5 STS-1 #6 STS-1 #7, GID-a, SQ#=3, CTRL=EOS STS-1 #8, GID-b, SQ#=0, CTRL=NORM Client Signal E STS-1 #9, GID-b, SQ#=1, CTRL=NORM STS-1 #10, GID-b, SQ#=2, CTRL=EOS STS-1 #11 STS-1 #12, GID-a, SQ#=255, CTRL=IDLE NMS/EMS provisions Source and Sink to add STS-1 #12 to group A as a 5th member (Path Trace is added to STS-1 #12) Source sends CTRL=IDLE in the channel to be added Sink returns MS=FAIL for member #4 at this stage 37 2004 Presentation to the Oregon IEEE Section LCAS Example – Adding to a Channel (Part 2) STS-1 #1, GID-a, SQ#=0, CTRL=NORM STS-1 #2, GID-a, SQ#=1, CTRL=NORM PMC-SIERRA Client Signal A STS-1 #3, GID-a, SQ#=2, CTRL=NORM STS-1 #4 STS-1 #5 STS-1 #6 STS-1 #7, GID-a, SQ#=3, CTRL=EOS STS-1 #8, GID-b, SQ#=0, CTRL=NORM Client Signal B Client Signal C Client Signal D Client Signal E STS-1 #9, GID-b, SQ#=1, CTRL=NORM STS-1 #10, GID-b, SQ#=2, CTRL=EOS STS-1 #11 STS-1 #12, GID-a, SQ#=255, CTRL=ADD Source sends CTRL=ADD in the channel to be added Source waits for sink to respond with MS=OK for #4 - Note that the MS for all members is sent in the control packets of each member 38 2004 Presentation to the Oregon IEEE Section LCAS Example – Adding to a Channel (Part 3) STS-1 #1, GID-a, SQ#=0, CTRL=NORM STS-1 #2, GID-a, SQ#=1, CTRL=NORM PMC-SIERRA Client Signal A STS-1 #3, GID-a, SQ#=2, CTRL=NORM STS-1 #4 STS-1 #5 STS-1 #6 STS-1 #7, GID-a, SQ#=3, CTRL=NORM STS-1 #8, GID-b, SQ#=0, CTRL=NORM Client Signal B Client Signal C Client Signal D Client Signal E STS-1 #9, GID-b, SQ#=1, CTRL=NORM STS-1 #10, GID-b, SQ#=2, CTRL=EOS STS-1 #11 STS-1 #12, GID-a, SQ#=4, CTRL=EOS Source sends CTRL=EOS in the last (new) channel and NORM in the next-to-last channel The added channel carries traffic in the first frame after the end of the control packet that carried the CTRL=NORM/EOS change 39 2004 Presentation to the Oregon IEEE Section LCAS Example – Adding to a Channel (Part 4) STS-1 #1, GID-a, SQ#=0, CTRL=NORM STS-1 #2, GID-a, SQ#=1, CTRL=NORM PMC-SIERRA Client Signal A STS-1 #3, GID-a, SQ#=2, CTRL=NORM STS-1 #4 STS-1 #5 STS-1 #6 STS-1 #7, GID-a, SQ#=3, CTRL=NORM STS-1 #8, GID-b, SQ#=0, CTRL=NORM Client Signal B Client Signal C Client Signal D Client Signal E STS-1 #9, GID-b, SQ#=1, CTRL=NORM STS-1 #10, GID-b, SQ#=2, CTRL=EOS STS-1 #11 STS-1 #12, GID-a, SQ#=4, CTRL=EOS Once the new bandwidth has be connected, the Sink sends RS-ACK to the source to acknowledge the new sequence At the same time, the Sink sets its MS to be consistent with the new sequence 40 2004 Presentation to the Oregon IEEE Section LCAS Example – Deleting a Channel (Planned) STS-1 #1, GID-a, SQ#=0, CTRL=NORM STS-1 #2, GID-a, SQ#=1, CTRL=NORM Client Signal A STS-1 #3, GID-_, SQ#=255, CTRL=IDLE Client Signal B Client Signal C Client Signal D STS-1 #4 STS-1 #5 STS-1 #6 STS-1 #7, GID-a, SQ#=2, CTRL=NORM STS-1 #8, GID-b, SQ#=0, CTRL=NORM Client Signal E STS-1 #9, GID-b, SQ#=1, CTRL=NORM STS-1 #10, GID-b, SQ#=2, CTRL=EOS STS-1 #11 STS-1 #12, GID-a, SQ#=3, CTRL=EOS PMC-SIERRA Deletion shown here from the middle of the group, with subsequent Sequence Numbers adjusted accordingly The Sink sends RS-ACK to acknowledge the new sequence 41 2004 Presentation to the Oregon IEEE Section Service Restoration with LCAS PMC-SIERRA The LCAS service restoration capability gives a very powerful new paradigm - LCAS can exploit the diverse routing of members to restore data services at a lower rate (reduced channel size). - While voice and video channels must typically operate at the full rate, most data services can continue to operate at a reduced rate. - Allows a tremendous potential overall network bandwidth savings by eliminating the need for 1:1 redundancy. Example of new paradigm - The virtually concatenated channel size is set for the desired customer client bandwidth - Provisioning insures that no single (otherwise unprotected) route through the network contains more members than constitute the minimum customer channel size requirement. 42 2004 Presentation to the Oregon IEEE Section LCAS Service Restoration Example DCS SQ=0 SQ=1 SQ=0 SQ=1 SQ=2 SQ=3 SQ=4 DCS SQ=1 SQ=2 SQ=3 SQ=4 DCS SQ=2 SQ=3 SQ=4 RING ADM RING ADM RING ADM DCS SQ=1 SQ=0 SQ=1 RING ADM SQ=0 SQ=0, SQ=1 RING ADM PMC-SIERRA VCAT PTE RING ADM VCAT PTE CTRL=DNU for SQ=0 & SQ=1 MST=FAIL for SQ=0 & SQ=1 SQ=2, SQ=3, SQ=4 Due to diverse routing, only some members are affected by the network fault LCAS handles the fall-back to the unaffected members 43 2004 Presentation to the Oregon IEEE Section LCAS Service Restoration Example – LCAS signaling S T S -1 # 1 , G ID -a , S Q # =0 , C T R L =N O R M S T S -1 # 2 , G ID -a , S Q # =1 , C T R L =N O R M PMC-SIERRA C lie n t S ign a l A S T S -1 # 3 , G ID -a , S Q # =2 , C T R L =D N U S T S -1 # 4 S T S -1 # 5 S T S -1 # 6 S T S -1 # 7 , G ID -a , S Q # =3 , C T R L =N O R M S T S -1 # 8 , G ID -b , S Q # =0 , C T R L =N O R M C lie n t S ign a l B C lie n t S ign a l C C lie n t S ign a l D C lie nt S igna l E S T S -1 # 9 , G ID -b , S Q # =1 , C T R L =N O R M S T S -1 # 1 0 , G ID -b , S Q # =2 , C T R L =E O S S T S -1 # 1 1 S T S -1 # 12 , G ID -a , S Q #=4 , C T R L =E O S • The CTRL=DNU insures correct operation when the fault clears or under signal degrade conditions 44 2004 Presentation to the Oregon IEEE Section LCAS Details - Where is the LCAS Signaling Protocol Carried? PMC-SIERRA For SONET STS (SDH High Order VCs), it is communicated in a Control Packet carried in bits 1-4 of the H4 byte - Carried across a 16 frame multiframe For SONET VTs (SDH Low Order VCs), it is communicated in a Control Packet in bit 2 of the Z7 byte - Carried across a 32 frame multiframe For DS1, DS3, E1, and E3 it is communicated in the first eight bits of each multiframe 45 2004 Presentation to the Oregon IEEE Section H4 Encoding for HO LCAS H4 byte bit1 Bit 2 Bit3 Bit 4 Bit 5 st PMC-SIERRA Bit 6 Bit 7 Bit 8 1st multiframe no. 1 multiframe indicator MFI1 (bits 1-4) Sequence indicator MSBs (bits 1-4) Sequence indicator LSBs (bits 5-8) 2nd multiframe indicator MFI2 MSBs (bits 1-4) 2nd multiframe indicator MFI2 LSBs (bits 5-8) CTRL GID (“000x”) Reserved (“0000”) Reserved (“0000”) CRC-8 CRC-8 Member status Member status RS-ACK Reserved (“0000”) Reserved (“0000”) Reserved (“0000”) Sequence indicator SQ MSBs (bits 1-4) Sequence indicator SQ LSBs (bits 5-8) 2nd multiframe indicator MFI2 MSBs (bits 1-4) 2nd multiframe indicator MFI2 LSBs (bits 5-8) CTRL GID (“000x”) 1 1 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 1 1 1 0 0 0 0 1 1 1 1 0 0 0 0 1 1 1 1 0 0 0 0 1 1 1 1 0 1 1 0 0 1 1 0 0 1 1 0 0 1 1 0 0 1 1 0 0 1 1 0 0 1 1 0 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 14 15 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 0 1 2 3 4 5 6 7 8 2nd multiframe no. n-1 n The blue portion shows one complete Control Packet Control Packet consists of: Member Status RS-ACK opportunity Sequence Indicator Multiframe Indicator CTRL word Group ID (GID) CRC-8 n+1 • 46 2004 Reserved (“0000”) Reserved (“0000”) CRC-8 CRC-8 Member status Presentation to the Oregon IEEE Section How is Hitless Switching Accomplished? PMC-SIERRA Changes take place in the STS frame immediately following the one containing the last Control Packet bits for the Control Packet with the change information. - Remember that all member STSs are simultaneously carrying multiframe-aligned Control Packets As illustrated in the examples, the changes can include: - Adding members - Deleting members - Rearranging the Sequence Numbers (although per agreement, this re-arrangement is only allowed at an add/delete event) 47 2004 Presentation to the Oregon IEEE Section LCAS’s Role Relative to L2/L3 Methods PMC-SIERRA LCAS is an L1 protocol - Simple for carriers to manage - Bandwidth (service level) is guaranteed by provisioning (in fault-free network) - Service restoration is automatic, very fast (<50ms), and deterministic - Bandwidth granularity is determined by the member size - Response time is determined mainly by the control plane latency - L1 guarantees security of client signals. - Transport network providers have tools in place for L1 approaches - Maximizes use of existing infrastructure and OAM&P procedures 48 2004 Presentation to the Oregon IEEE Section LCAS’s Role Relative to L2/L3 Methods (continued) PMC-SIERRA L2/L3 methods - Multiple clients share a single channel (fat pipe approach) - Very fast response time to dynamic load variation (Implemented by the ingress node or via discard procedures in the network) - Greater bandwidth granularity flexibility - Potential for increased bandwidth efficiency through statistical multiplexing - Traffic engineering more complicated for carriers - Service level agreements require policing and traffic engineering - Service restoration requires L2/L3 processing and typically takes much longer (e.g., 30-60 sec. for Ethernet Spanning Tree Protocol) - L2/L3 networks are new for transport providers, and hence an expensive overlay. 49 2004 Presentation to the Oregon IEEE Section LCAS’s Role Relative to L2/L3 Methods (conclusion) PMC-SIERRA There are applications where both L1 and L2/L3 approaches have distinct advantages. While an L2/L3 approach is often preferred by service providers, an L1 approach is advantageous for transport network providers. 50 2004 Presentation to the Oregon IEEE Section Generic Framing Procedure (GFP) Defined in ITU-T Recommendation G.7041. Two modes of GFP - Frame mapped GFP (GFP-F) - Point-to-point - Single client frame mapped into single GFP frame. PMC-SIERRA - Transparent GFP (GFP-T) - Character mapped for transparency. - 8B/10B codes are grouped and translated into 64B/65B codes for better efficiency, - No MAC layer termination. - Optimized for low-latency, constant bit-rate applications (e.g., SAN or digital video delivery). - Both types use the same underlying GFP frame format. 51 2004 Presentation to the Oregon IEEE Section Motivation for GFP Drawbacks of Existing Technologies ATM: - Cell overhead causes 10% bandwidth inflation. - Adaptation functions are complex. PMC-SIERRA Packet over SONET (PoS): - Requires all frames to be converted to PPP over HDLC. - The use of HDLC for frame delimiting causes a nondeterministic bandwidth inflation. GFP maximizes transparency by encapsulating the client data with a minimum of client protocol awareness required. 52 2004 Presentation to the Oregon IEEE Section Motivation for GFP Application Drivers PMC-SIERRA Simple transport of client packets/frames in their native format Aggregation of frames from multiple clients (and multiple client types) into shared bandwidth channels - Statistical multiplexing for bandwidth efficiency Metro access Storage Area Networks (SAN) 53 2004 Presentation to the Oregon IEEE Section GFP Frame 16-bit PAYLOAD LENGTH INDICATOR cHEC (CRC-16) PTI TYPE HEADER (4 BYTES) PAYLOAD HEADERS OPTIONAL EXTENSION HEADER (0-60 BYTES) PFI UPI CRC-16 EXI PMC-SIERRA CORE HEADER PAYLOAD AREA CLIENT PAYLOAD INFORMATION FIELD OPTIONAL PAYLOAD FCS (CRC-32) 54 2004 Presentation to the Oregon IEEE Section Frame Mapped GFP (GFP-F) Target Applications Examples Application examples: PMC-SIERRA - Transparent L2 bridging - Allows combining multiple clients and multiple protocol types in the same channel. Mappings exist for: - Ethernet - PPP - Fibre Channel - MPLS - RPR (Adopted for use with IEEE 802.17 Resilient Packet Ring) Proposals have been made to do routing at the GFP layer to minimize processing of higher layers. 55 2004 Presentation to the Oregon IEEE Section Frame Mapped GFP – Ethernet MAC Frame Example Ethernet MAC Frame Octets 2 2 2 2 0 - 60 GFP Frame PLI cHEC Type tHEC GFP Extension Hdr PMC-SIERRA Octets 7 1 6 6 2 4 Preamble Start of Frame Delimiter Destination Address (DA) Source Address (SA) Length/Type MAC client data Pad Frame Check Sequence (FCS) GFP Payload Bit # 0 1 2 3 4 5 6 7 0 1 2 3 4 5 6 7 Ethernet and GFP frame relationships 56 2004 Presentation to the Oregon IEEE Section Transparent GFP (GFP-T) PMC-SIERRA Transparent character mapping for 8B/10B encoded client signals. - SAN protocols (ESCON, Fibre channel, FICON) - Gbit Ethernet - Digital Video Broadcast (DVB-ASI) Transparently transports client 8B/10B control characters as well as data characters. Uses fixed-length frames uncorrelated with the client frames. Higher efficiency and low latency - Effectively creates a constant bit rate service. Supports either full-rate or sub-rate service 57 2004 Presentation to the Oregon IEEE Section Transparent GFP – Example 6 4 B /6 5 B c o d e b lo c k PMC-SIERRA L e a d in g b it 8 x 6 4 B /6 5 B b lo c k s C o d e le a d in g b its re p o s itio n e d in to a tra ilin g b y te ... ... C R C -1 6 C o re a n d P a y lo a d H e a d e rs S u p e rb lo c k (8 x 6 4 B /6 5 B c o d e s + C R C -1 6 ) G F P -T F ra m e w ith 4 s u p e rb lo c k s Fixed number of 64B/65B blocks per GFP frame 58 2004 Presentation to the Oregon IEEE Section 10GBASE-W Ethernet IEEE 802.3ae PMC-SIERRA The WAN-PHY interface for 10G Ethernet was defined to use the payload envelope of a SONET STS-192c - The 10GBASE-W signal uses a UNI-type subset of the SONET overhead bytes and relaxed transmit jitter specification. Can be carried transparently over G.709 OTN (ODU2) For interworking with SONET, it requires enhancement/adaptation to use SONET synchronization and jitter specifications in order to avoid generating SONET network alarms. 59 2004 Presentation to the Oregon IEEE Section Resilient Packet Ring (RPR) IEEE 802.17 Defines a packet add/drop ring - Insertion buffer technique PMC-SIERRA Primarily intended for access and metro applications Can use either SONET or native Ethernet for its physical layer - Supports both GFP and PoS for encapsulation. Has the necessary traffic management features (e.g., shaping and flow control) for ensuring fair access by multiple customers. Has protection mechanisms for Layer 2 restoration. Includes Layer OAM. 60 2004 Presentation to the Oregon IEEE Section The question of tagging PMC-SIERRA When Ethernet frames from multiple customers or multiple flows share the same channel, how does the carrier tag them? - Carrier IEEE 802.1Q VLAN tags or stacked VLAN tags (Q-in-Q) - Simple technology that already exists - 12-bit field allows only 4096 tags (too small) - Carrier stacks its own Ethernet MAC addresses (MAC-in-MAC) - Not well received so far, but still being considered - Some risk regarding data frame length expansion 61 2004 Presentation to the Oregon IEEE Section The question of tagging (continued) - MPLS encapsulation - Has considerable support from vendors and carriers - Existing technology and protocols - 20-bit tag size is a much better fit for large networks PMC-SIERRA - Extended GFP (i.e., a new, MPLS-like Extension Header) - Allows clear separation of carrier overhead from user and service provider overhead, and eliminates processing layers at switching points - Proposed, but status uncertain 62 2004 Presentation to the Oregon IEEE Section Multi-Protocol Label Switching(MPLS) PMC-SIERRA Developed by the IETF to allow data to be routed based on Label Switched Paths (LSPs) - Data on each LSP is part of the same Forwarding Equivalency Class (FEC) Some key points relative to Ethernet transport - Can encapsulate and carry Ethernet frames - Provides a rich tagging mechanism for packet multiplexing multiple Ethernet customers and flows - OAM and protection features exist or are being added - Fits with plans by major carriers (e.g., AT&T, MCI, and BT) and equipment vendors (e.g., Alcatel and Lucent) to use MPLS as a core network technology 63 2004 Presentation to the Oregon IEEE Section MPLS header example PMC-SIERRA L-LSP Fo rw a rd ing + Co S DP Label (20 bits) E-LSP Fo rw a rd ing EXP (3b) S (1b) Co S+DP TTL (8b) MPLS headers can be stacked 64 2004 Presentation to the Oregon IEEE Section Conclusion PMC-SIERRA Carriers and enterprise customers need a technology to support higher-rate data services Carriers are anxious for new revenue-generating services Ethernet is the natural preference on the enterprise side The new pieces are coming together to: - Define Ethernet services for multi-carrier interworking - Efficiently carry Ethernet over the SONET/SDH core infrastructure - Provide carrier-grade OAM and QoS Cautionary note: A problem for carriers is that increased bandwidth and new technology always adds cost, but subscribers expect Ethernet to be cheaper. 65 2004 Presentation to the Oregon IEEE Section References (tutorial) PMC-SIERRA “Generic Framing Procedure and Data over SONET/SDH,” feature topic in IEEE Communications Magazine, May 2002 “Ethernet WAN Transport,” feature topic in IEEE Communications Magazine, March 2004 K. Kazi (editor), Comprehensive Guide to Optical Networking Standards, upcoming book from Springer M. Elanti, S. Gorshe, L. Raman, & W. Grover, Next Generation Transport Networks, upcoming book from Springer 66 2004 Presentation to the Oregon IEEE Section References (ITU-T standards) PMC-SIERRA ITU-T Recommendation G.8010/Y.1306 (2004), Ethernet Layer Network Architecture ITU-T Recommendation G.8011/Y.1307 (2004), Ethernet Services Framework ITU-T Recommendation G.8011.1/Y.1307.1 (2004) Ethernet Private Line Service ITU-T Recommendation G.8012/Y.1308 (2004), Ethernet UNI and Ethernet NNI ITU-T Recommendation G.8021/Y.1341 (2004), Characteristics of Ethernet transport network equipment functional blocks 67 2004 Presentation to the Oregon IEEE Section References (ITU-T standards continued) PMC-SIERRA ITU-T Recommendation G.7042 (2004), Link Capacity Adjustment Scheme (LCAS) for Virtual Concatenated signals ITU-T Recommendation G.7041 (2004), Generic Framing Procedure (GFP) ITU-T Recommendation G.7043/Y.1343 (2004), Virtual concatenation of Plesiochronous Digital Hierarchy (PDH) signals ITU-T Recommendation G.8040 (2004), GFP frame mapping into Plesiochronous Digital Hierarchy (PDH) 68 2004 Presentation to the Oregon IEEE Section References (IEEE and MEF standards) PMC-SIERRA IEEE 802.17-2004, Information technology – Telecommunications and information exchange between systems – Local and metropolitan area networks, Specific requirements – Part 17: Resilient Packet Ring Access Method & Physical Layer Specifications (RPR) IEEE 802.3AH-2004 Standard for Local and metropolitan area networks— Part 3: CSMA/CD access method and physical layer specifications Amendment: Media Access Control Parameters, Physical Layers and Management Parameters for Subscriber Access Networks MEF 1, Ethernet Services Model – Phase 1, 2003 MEF 2, Requirements and Framework for Ethernet Service Protection in Metro Ethernet Networks, 2004 MEF 4, Metro Ethernet Network Architecture Framework - Part 1: Generic Framework, 2004 MEF 5, Traffic Management Specification: Phase I, 2004 69 2004 Presentation to the Oregon IEEE Section PMC-SIERRA PMC-SIERRA Thinking You Can Build On www.pmc-sierra.com 70 2004 Presentation to the Oregon IEEE Section