Cisco RPR. Technology Fundamentals. 권선국부장 Cisco Systems Korea F0_5629_c , Cisco Systems, Inc.

Transcription

1 Cisco RPR Technology Fundamentals 권선국부장 Cisco Systems Korea 1

2 Agenda Overview SRP Protocol and Features Application Summary 2

3 Today s Metro Internet The TDM Bottleneck OC12/48 POS Core routers CHOC12/48 DACS ADM ADM SONET OC-48 ADM ADM DACS ADM ADM SONET OC-12 ADM ADM CSU/ DSU CSU/ DSU CSU/ DSU T1 CSU/ DSU CSU/ DSU High-end router OC3 CSU/ DSU SoHo router T3 Mid-range router Ethernet/IP Point of Presence Regional Metro Local CO Metro Access Customer Premise Provisioned TDM optical transport architecture (SONET/SDH) Traditional data (IP) backhaul overlay DSn/OCn customer subscriber interfaces IP services and provisioning bottleneck 3

4 Cisco RPR Solutions Bringing the Power of the IP to the Metro Edge IP/MPLS 3 Basic Ingredients Optical Infrastructur e Etherne t Ethernet/IPenabled edge Enterprise Optimize metro optical infrastructure for simple, scalable, and reliable IP internetworking Enable direct Ethernet customer connectivity Enable profitable Ethernet/IP services portfolio Simplify operations and service delivery 4

5 Cisco RPR Solutions Optimize the Metro Optical Infrastructure B-ISDN IP over ATM IP over SONET/SDH IP over Optical IP Multiplexing, Protection, and Management at Every Layer ATM IP IP SONET/SDH Optical ATM Optical SONET/SDH Optical IP IP-aware Optical } Cisco RPR Lower Cost, Complexity, and Overhead 5

6 Tomorrow s Internet Access Model Simplified Core-Edge Architecture: Supercharged for Profitability Access Network L3 Core Network Access Network Cisco Series Cisco Series Cisco Series Cisco Series Metro Ethernet/IP Access Regional Metro IP/MPLS Core Regional Metro Metro Ethernet/IP Access Ethernet Interface Ethernet Interface Full Service Network High-speed Internet Ethernet Private Line IP VPNs Voice/Video/TDM over IP Security services Content services High speed IP High speed IP High speed IP Full Service Network High-speed Internet Ethernet Private Line IP VPNs Voice/Video/TDM over IP Security services Content services Bringing the Intelligence, Scalability and Service Richness of IP to the Metro Edge 6

7 Key Cisco RPR Solution Requirements Radically improve network economics via layer elimination, bandwidth multiplication and plugand-play operations Provide Fast IP Service Protection and Restoration against fiber and node failures Provide Infrastructure Transparency Key Component of High Bandwidth Metro Access and Distribution Strategy to Extend Optical to the Network Edge 7

8 Cisco RPR Features Basic packet processing Fairness Algorithm Multicasting Intelligent Protection Switching Topology discovery ARP and routing Network management 8

9 SRP Overview SRP provides Cisco RPR functionality New MAC for LAN, MAN and WAN applications Dual counter rotating rings Spatial reuse 9

10 SRP Overview(cont) Multicast support Supports traffic prioritization SRP fairness algorithm (SRP-fa) controls access to the ring and enforce fairness Scalable - Nodes/ Distance 10

11 SRP Overview(cont) Intelligent Protection Switching (IPS) Survivability in the event of fiber facility or node failure, or signal degradation Media independent protocol Initial implementation uses SONET/SDH framing Plug-and-play operation - Topology Discovery 11

12 SRP Ring Control Packet GSR GSR Data Packet Inner Ring Outer Ring Example of a 4 Node SRP Ring 12

13 Spatial Reuse The spatial reuse capability increases ring capacity Bandwidth is consumed only on traversed segment Unicast packets travels along ring spans between the src and dest nodes only Destination stripping A D B C 13

14 Agenda Overview SRP Protocol and Features Metro Application Summary 14

15 SRP Packet SRP is a media independent MAC layer protocol The initial implementation utilizes SONET/SDH framing Concatenated payloads only Transport Overhead Path Overhead Synchronous Payload Envelope (SPE) 125 µsec F L A G SRP MAC Header IP Payload F C S F L A G 15

16 SRP Packet Formation IP Packet Application NOS SRP Header IP Packet FCS SRP SONET OH SRP SRP SRP SRP SRP SONET FRAMER SRP Headers and FCS are attached to IP packets SRP Packets are placed into the payload of a SONET frame 16

17 SRP v2 Generic Header Time to Live (TTL) RI MODE PRI P Time to Live (TTL) 8 bit hop count field; decremented each time a node forwards a packet; if the TTL reaches zero the packet is stripped from the ring Ring Identifier (RI-bit) 0 1 Outer Ring Inner Ring Mode Value Description Unused Control Message (Pass to host) Control Message (locally buffered) Unused Data Packet Priority Field (PRI) Indicates the priority level of a SRP packet; valid values 0 7, with higher values indicating higher priority Parity Bit Odd parity over previous 15 MAC header bits 17

18 SRP v2 Data Packet Format Time to Live (TTL) RI MODE PRI P Destination MAC Address Source MAC Address Protocol Type Payload FCS 18

19 SRP v2 Control Packet Format Time to Live (TTL) RI MODE PRI P Destination MAC Address Source MAC Address Control Ver Protocol Type Control Type Control Checksum Control TTL Payload FCS 19

20 SRP v2 Control Packets Usage Topology discovery Intelligent Protection Switching (IPS) 20

21 SRP MAC Addressing Each interface has a globally unique IEEE 48 bits MAC address Ethernet style To support multicast a multicast bit is defined using canonical addressing conventions 21

22 Single Subnet Both Outer and Inner rings are on the same IP subnet This enables rapid re-optimization of ring path selection and minimize route flaps in a ring wrap situation Ring wraps are handled by the lower layer and are transparent to layer 3 routing protocols 22

23 SRP Protocol and Features Packet processing Multicasting Priority Fairness Pass-through Ring selection Topology discovery Intelligent Protection Switching (IPS) Management 23

24 Receive Packet Handling Packet acceptance and processing Control packet processing Control Packet Processing Data Packet Processing Multicast handling Address Lookup Lo Priority Hi Priority Transit Buffer Accounting Rx Fiber Rx Packet Processing Hi Priority Lo Priority 24

25 Receive Packet Handling Six Things Can Happen to an Incoming Packet Received and stripped Forwarded Stripped Received and forwarded Wrapped Pass-through 25

26 Multicast Handling Arriving multicast packets are forwarded to the host s processing module The multicast packets are then placed into the transit buffer for continued circulation Unlike unicast packets, multicast packets are stripped at their source 26

27 Transmit Packet Handling Priority handling Lo Priority Transmit Queues Hi Priority Transmit decision algorithm Fairness Hi Priority Lo Priority Transit Buffer X Tx Fiber High Threshold Low Threshold Fairness Signaling 27

28 Priority Handling The priority field is set by the source node The node utilizes a mapping between the IP precedence bits in the ToS field into the SRP MAC header priority field 28

29 Priority Handling A configurable priority threshold is used to determine if the packet should be placed in the HIGH or LOW priority queues Maps 8 levels of priority to 2 levels This is the same for both locally sourced packets and transit packets 29

30 SRP Fairness Algorithm SRP-fa is the mechanism that ensures Global Fairness each node gets a fair share of the ring bandwidth Local Optimization spatial reuse optimizes bandwidth utilization over traversed links Scalability the ability to build large rings with many nodes that spans across large geographically distributed area 30

31 SRP-fa Operation Example Node D- Node C Mbps Mbps A B Node A Mbps C D 3 Nodes Transmitting 300Mbs to Node B on 622Mbps ring 31

32 SRP-fa Operation Example 32

33 SRP-fa High priority transmit packets are not rate controlled by the SRP-fa May use Committed Access Rate (CAR) Excess transit packets are not rate limited by the node instead it sends a fairness message upstream 33

34 Topology Discovery Each node performs topology discovery by sending out topology discovery packets on the Outer ring Each node on the ring appends its MAC address binding, updates the length field and sends it to the next node on the ring 34

35 Topology Discovery If there is a wrap on the ring the wrapped node will indicate a wrap when appending its MAC binding and wraps the packet When a topology packet follows a wrap, MAC binding and wrap status are not appended to the packet 35

36 Ring Selection Ring selection is done by ARP A responding node uses its topology map to determine on which ring to send a response E A B Responses are sent on the longer path ARP Request D C Requesting node uses response to determine ring selection ARP Response Topology Map 36

37 Ring Selection When a node detects a ring wrap or unwrap it flushes the ARP cache to trigger a ring selection Static ARP can be used to force the selection of a particular ring Feature to enter cost/span currently in development 37

38 Cisco RPR Management RFC 2558 SONET/SDH MIB Current status and alarm Current and historical Errored Seconds (ES), Severe Errored Seconds (SES), Severe Errored Framing Seconds (SEFS), Coding Violations (CV) and Unavailable Seconds (UA) counts SRP MIB - IETF Draft SRP MAC statistics 38

39 Intelligent Protection Switching IPS provides SRP with a powerful self healing feature which automatically recovers from fiber facility or node failure, or signal degradation IPS is analogous to the self healing properties of SONET/SDH rings but without the need to allocate protection bandwidth 39

40 IPS Proactive fault and performance monitoring Event detection and reporting Signal processing and propagation to communicate faults detected or clearances Allow for rapid recovery and restoration 40

41 IPS Topology knowledge independence Ring wrapping to bypass failed fiber or node Transparent to the layer 3 routing protocols Protection switching event hierarchy Ring restores in 50 msecs 41

42 IPS Request Type (Automatic) Signal Fail (SF) Performs a wrap; caused by a hard failure LOS, LOF, Line BER above a specified threshold, Line AIS, keepalive failure or excessive CRC errors Signal Degrade (SD) Performs a wrap; caused by soft failure Line BER above a specified threshold or excessive CRC errors Wait to Restore (WTR) When a wrap condition clears instead of unwrapping immediately the node waits for a configured period of this before unwrapping; this is to prevent protection switch oscillation 42

43 IPS Request Type (Operator Originated) Hold Off (HO) Delays ring wraps anywhere in the ring; if a wrap is present it causes it to drop. Allows 100ms for another Layer1 protection mechanism to react. Forced Switch (FS) Performs a wrap at the node at which this command was issued and at the adjacent node Manual Switch (MS) Similar to FS but at a lower priority 43

44 IPS Triggers Hard failure Signal Fail (SF) Soft failure Signal Degrade (SD) Operator HoldOff Protection (HO) Forced Switch (FS) Manual Switch (MS) 44

45 Protection Request Hierarchy Highest Priority Lowest Priority HoldOff Protection (HO) Forced Switch (FS) Signal Fail (SF) Signal Degrade (SD) Manual Switch (MS) Wait to Restore (WTR) No Request (IDLE) 45

46 SONET/SDH Overhead Usage Loss of Frame (LOF) A1 and A2 overhead bytes Loss of Signal (LOS) Alarm Indication Signal (AIS) Bit Error Rate (BER) B2 overhead byte 46

47 IPS States Idle Pass-through Wrapped 47

48 IPS States Idle The node is ready to perform a protection switch Pass-through An extension of the Idle state. Forwards received long path IPS packet 48

49 IPS States Wrapped The node enters this state when it receives a local request or detects a fault or receives a short path IPS packet from an adjacent node Performs a wrap 49

50 O-Tx I-Rx I-Tx O-Rx O-Rx I-Tx I-Rx O-Tx Wrapped Packet Flow L3 SRP-LC MAC MAC O-Tx I-Rx Wrapped X O-Rx Wrapped I-Tx MAC MAC SRP-LC L3 MAC MAC L3 SRP-LC MAC I-Tx O-Rx I-Rx O-Tx MAC SRP-LC L3 50

51 IPS Operation {0,A,0,S} Idle A B Idle C D Idle Normal Working Idle 51

52 IPS Operation Wrapped {0,A,W,S} A X B Wrapped Fiber Cut {SF,B,W,S} {SF,A,W,L} {SF,B,W,L} C D Pass-Through 1 Fiber Failure Pass-Through 52

53 Detecting a New Neighbor E Outer Ring Neighbour C Inner Ring Neighbour B {0,A,0,S} A B {0,B,0,S} Outer Ring Neighbour A Inner Ring Neighbour D C D 53

54 Detecting a New Neighbor E Outer Ring Neighbour C Inner Ring Neighbour B {SF,A,W,S} A X X {SF,B,W,S} B Outer Ring Neighbour A Inner Ring Neighbour D {SF,A,W,L} {SF,B,W,L} C D 54

55 Detecting a New Neighbor {0,E,0,S} E Outer Ring Neighbour C Inner Ring Neighbour B A B Outer Ring Neighbour A Inner Ring Neighbour D A Detects New Neighbour B Detects New Neighbour C D 55

56 Agenda Overview SRP Protocol and Features Metro Application Summary 56

57 Metro Applications Cisco RPR / IP Solutions Metro/City Ring Network Application Cisco RPR Enables Extended Transparent LAN Services Cisco RPR ISP Exchange network Application Cisco RPR/ IP Access Systems Cisco RPR Solution Product Portfolio 57

58 Cisco RPR / IP Solutions Simplify Operations and Service Delivery Access Network L3 Core Network Access Network Cisco Series Cisco Series Cisco Series Cisco Series Metro Ethernet/IP Access Regional Metro IP IP Core Regional Metro IP Metro Ethernet/IP Access Reduce network equipment layers Simplify installation and deployment Minimize operator expertise and expense Minimize truck rolls 58

59 Metro/City Ring Network Application Customer A Multi Tenant Unit - Business Direct Ethernet Intra-City POP Multi Tenant Unit - Business Customer B GE or FE CAR per Mbps Increment Customer C i.e. 200Mbps Transit Service Customer D OC48/STM16 DPT/RPR Dual Homed Customer Metro Access Ring 59

60 Si Si Si Si Si Si Cisco RPR Enables Extended Transparent LAN Services IP Video Cisco RPR Capabilities Priority Multicasting Protection MAC filtering IP Voice GSR GSR GSR Service Provider PoP Provides Foundation for Enhanced MAN/WAN including voice and video over IP, Managed Bandwidth, and Protected Services 60

61 Cisco RPR ISP Exchange network Application Exchange Point A ISP A ISP B Exchange Point B Cisco ONS Inner Ring Outer Ring Cisco ONS ISP C ISP D Using the Cisco ONS and SRR feature for distributed exchange point Provides valuable statistics for mediation/ settlement systems 61

62 Cisco RPR IP Access Systems Hub & Spoke Application Cisco ONS Cisco Series Inner Ring Outer Ring Cisco Series Leverage Multi-Tenant ONS and SRR protocol to Unit Unit construct logical rings over physical hub and spoke topologies Intelligent optical distribution layer (vs. traditional L2 switching distribution layer Readily scale system capacity Multi-Dwelling 62

63 Cisco RPR/IP Access Systems Building Highly Scalable Metro Access Systems Cisco Series Multi-Tenant Unit 1 Logical DPT Ring Multi-Dwelling Unit Cisco Series 1 Logical DPT Ring 1 Logical DPT Ring Cisco ONS High speed regional IP systems for metro internetworking System architecture easily scales to support millions of user and terabits of bandwidth 63

64 Cisco RPR / IP Applications Solutions Portfolio High-speed MxU Ethernet Access ubr Series HFC Metro Optical Infrastructure Cable MSO Systems HFC Intra-PoP Systems Metro Ethernet/IP Access Systems Regional Metro IP Systems IP Core SONET/SDH Regional (IOF) Ring SONET/SDH Access Ring ADM High-speed Internet Ethernet Private Line IP VPNs Voice/Video over IP Security services Content services ISP A ISP B Exchange Point Systems ISP C Server Farm Systems Enterprise Campus/MAN Systems Campus/MAN Backbone Internet Cisco Series Cisco ONS Cisco Series 64

65 Cisco RPR / IP Solutions Optimize the Metro Optical Infrastructure Over 200 DPT Customers Worldwide Cisco Series OC48/STM16 DPT Cisco Series Multi-Dwelling Unit Multi-Tenant Unit Over 15,000 ports deployed Powered by Dynamic Packet Transport (DPT), the market-leading Resilient Packet Ring (RPR) solution for unparalleled simplicity, scalability and reliability Based on the Cisco-developed Spatial Reuse Protocol (SRP) IETF Informational RFC 2892 Submitted to IEEE Working Group (Cisco Group Chair) for consideration as the RPR industry standard 65

66 Cisco DPT/RPR Product Portfolio Product Portfolio Cisco 7500 Series Cisco 7200 Series Cisco Series ONS Cisco ubr 7200 Series ONS Cisco Series Cisco 7600 Series And Growing Series 66

67 Summary Cisco RPR solution delivers scalable Internet service, reliable IP-aware optical transport, and simplified network operations Use of DPT/RPR for 50ms restoration Ability to prioritize traffic such as Voice/Video Feature richness of the product: Multicast handling, BGP, MPLS VPN High Bandwidth/high performance, lower costs (CAPEX and OPEX) 67

68 _04F9_c1 68