1 / 64

Training

Training. ATM Basics. Overview. „What is ATM“ Physical Layers (PHY) ATM Layer (ATM) ATM Adaptation Layer (AAL) ATM Vision Basic Setup Practice. Section. What is ATM ?. Asynchronous Transfer Mode (ATM) „What is ATM?“. ATM = Switching and transmission technique.

jontae
Télécharger la présentation

Training

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Training ATM Basics

  2. Overview „What is ATM“ Physical Layers (PHY) ATM Layer (ATM) ATM Adaptation Layer (AAL) ATM Vision Basic Setup Practice

  3. Section What is ATM ?

  4. Asynchronous Transfer Mode (ATM) „What is ATM?“ ATM = Switching and transmission technique Header Information 5 Bytes 48 Bytes Voice ATM Cell ATM Multiplexer ATM Switch Data • Integration of multiple services • Operates at any speed, any PHY • Continuous or bursty traffic types • Single technology solution • International standard Video Image

  5. Section Physical Layer What is ATM

  6. Physical Interfaces Frame Bit ATM Cell Physical Format Rate Rate Media_______________ DS-3 (U.S.) 44.736 Mbps 104253 Cells/s Coax, microwave, SMF E3 34.368 Mbps 80000 Cells/s Coax, microwave, SMF ATM2525.6 Mbps 59108 Cells/s UTP-3, STP STM-1/STS-3c 155.52 Mbps 353207 Cells/s SMF, MMF, Coax, UTP-3 & 5 STM-4/STS-12c 622.08 Mbps 1412828 Cells/s SMF, MMF, UTP-5 STM-16/STS-48 2.488 Gbps 5651312 Cells/s SMF DS: SMF: MMF: STS: STM: UTP-n: STP: Digital Signal Single-mode fiber Multi-mode fiber Synchronous Transport Signal (SONET) Synchronous Transport Module (SDH) Unshielded twisted pair-Category n Shielded twisted pair

  7. Section ATM Layer What is ATM Physical Layer

  8. Introdrucing the ATM Cell Structure Header Error Check (HEC) ATM Cell 53Bytes Header Payload 5 Bytes (9.4%) 48 Bytes (90.6%) Information from higher layers

  9. ATM Cell Header Enables High performance switching Ability to tailor bandwidth to exact customer needs Operations, Administration and Maintenance (OAM) capabilities allows fault detection, location andisolation

  10. UNI Cell Header Format Bit 7 6 5 4 3 2 1 0 GFC VPI VPI VCI 5 Bytes VCI UNI VCI PTI CLP HEC UNI = User Network Interface

  11. Network Node Interface (NNI) Cell Header Format 7 6 5 4 3 2 1 0 Bit VPI VPI VCI VCI 5 Bytes NNI VCI PTI CLP HEC • Extended VPI (12 bits) • Used between network nodes

  12. NNI Format Significance Expanded VP header enables up to 4096 VPs per PHY/Trunk Facilitates “traffic grooming” within the Service Provider network

  13. Generic Flow Control (GFC) • Currently undefined, set to 0000 • Proposed future uses • Flow control • Shared media multiple access control

  14. Virtual Paths (VPs) Physical Link Virtual Path Virtual Channel Virtual Path (VP) is a “bundle” of Virtual Channels

  15. ATM Virtual Channels (VCs) and VPs VP VP VCs VCs Physical Link e.g., SDH STM-1 VP VP VCs VCs Virtual Channels (VCs) carried in Virtual Paths (VPs) 256 VPs can be carried in a UNI Physical Link, 4096 VPs per NNI PHY 65,536 VCs can be carried in a UNI VP or NNI Virtual Path 16,777,216 VCs per UNI and 268,435,456 VCs per NNI PHY Virtual Channel Identifier (VCI) contained in ATM cell header Virtual Path Identifier (VPI) contained in ATM cell header Bandwidth can be flexibly assigned on per VP and VC basis End to end VC Connection (VCC) is concatenation of VCs between customer and network equipment elements At each end point a connection is uniquely identified by its VPI/VCI pair

  16. ATM VCs and VPs

  17. Payload Type Identifier (PTI) PT Value User Data Type 0 indicates ATM cell is not last cell of Protocol Data Unit (PDU). Type 1 indicates last cell of PDU Type = 0 Type = 1 000 001 No congestion Type = 0 Type = 1 010 011 Congested OAM F5 cell segment OAM F5 End-to-End cell 100 101 F5 Flow OAM Resource management Reserved future use 110 111 Traffic Payload contains Layer Management • Bit 3: Discriminates data cells from operations, administration, maintenance cells • Bit 2: Indicate congestion in data cells • Set by Switches • Source and destination behavior defined for Available Bit Rate (ABR) flow control • Bit 1: Carried transparentet end-to-end in data cells. Used by AAL5

  18. Cell Loss Priority (CLP) • Cells with CLP set should be discarded • prior to cells not having it set • Can be set at terminal • Can be set by ATM switches for internalcontrol • Services with low quality of service • Cells that violate traffic contract

  19. Header Error Check (HEC) Correction Mode: Corrects single bit errors When a correction is performed, begin detection mode Detection Mode: Detects multiple bit errors Discards cell when header error detected If no errors detected for three times, resume correction mode

  20. Cell Delineation Header Error Check (HEC) ATM Cell Header Payload • HEC is used for Cell Delineation • Receiver locks on 5 byte blocks that • satisfy the HEC calculation • are separated by 53 bytes • HEC is coded such that an empty Header (1st 4 Bytes = 0) will not makeHEC=0

  21. MAPPING USER DATA TO ATM Service Layer; e.g., Data Frame Service Protocol Data Unit (PDU) AAL Convergence Sublayer CS Header CS Trailer PAD Payload AAL SAR Sublayer Payload Payload . . . . . . . . . . Payload H T H T T H ATM Layer H Payload H Payload . . . . . . . . . . Payload H CS - Convergence Sublayer AAL - ATM Adaptation Layer H -Header SAR - Segmentation and Reassembly T -Trailer PDU - Protocol Data Unit

  22. Section ATM Adaption Layer What is ATM Physical Layer ATM Layer

  23. AAL Types AAL Type: AAL2 Appl Reqs: AAL1 AAL3/4 AAL5 Not Required Isochronous Timing Required Bit Rate Support Constant Variable Bit Rate Connection oriented Connection Mode Connection–oriented Conn- less Constant bit rate voice & video Variable bit rate voice & video Bursty bit rate data Bursty bit rate data

  24. ATM Service Classes Service Classes Attribute Class A Class B Class C Class D Synchronous (Clocking Required) Asynchronous (No Clocking) Timing relationship (source/destination) Constant Bit Rate Variable Connection-less Connection Mode Connection-oriented AAL 1 or AAL 5* AAL 3/4 or AAL 5 AAL 3/4 or AAL 5 ATM Adaptation Layers (AALs) AAL2 * Note: AAL 5 also specified for Voice, and for Audio/visual Multimedia Service (AMS) ATM Forum specifications. ITU-T Voice Recommendations require AAL 1 and use of AAL 5 as option. AAL0 = Null or no AAL. Also sometimes referred to as Class X service

  25. AAL SDU Formats 47 Bytes 1 bit 3 bits 4bits AAL 1 CSI SN SNP SAR-PDU 40 Bytes 1 byte 1 byte 2 byte 4 bytes AAL 5 CPCS- CPI L CRC SAR-PDU UU AAL1: CSI= Convergence sublayer indication SN = Sequence number SNP= Sequence number protection AAL5: CPCS-UU = Common Part Convergence Sublayer User-User Indication CPI = Common Part Indicator L = Length field CRC = Cyclic Redundancy Check field

  26. AAL 1 AAL1 Header Payload AAL 1 Header Functions include: SAR sequence number for cell loss detection Byte alignment for channelized Circuit Emulation Service (CES) e.g. channelized E1/T1 AAL1 used for constant Bit Rate Services 1 byte 47 bytes

  27. AAL1 FEC AAL1 Interleaving Matrix for FEC Writing order 124 Byte 4 Byte Reading order FEC .... .... 47 Byte 124 * 47 Byte = 6016 Bytes User data • Maximum corrections within one Matrix: • 4 cell losses • 2 cell losses and one errored byte each row • 2 errored byte in each row without cell losses

  28. AAL5 ••• SSCS ••• 8 byte trailer + PAD Data 48 bytes 48 bytes ••• Upper Layer Application Variable-length user data frame Data (1 – 65,535 bytes) ATM Adaptation Layer (AAL) AAL5 ATM (Cell) Layer 53–byte Cells ••• Physical Layer Framing and Rate Adaptation

  29. AAL5 0 - 65535 bytes Added 4 byte AAL Trailer ....User Data..... PAD 0 LEN CRC PAD forces right hand alignment 0 Payload ................................ 1 Payload PTI denotes last cell • Receiver simply places cell payloads into memory until • “last cell” indication occurs • It then checks the CRC, compares LEN to received length

  30. Setting Up ATM Connections • ATM is connection-oriented; there must always be a virtual connection established before cells can be sent • Connections can be established by: • Permanent Virtual Connections (PVCs) established Administratively – Based on Service Level Agreement (SLA) • Lowest common denominator for Interoperability for devices not supporting UNI signaling • Dynamically as Switched Virtual Connections (SVCs) – on demand • implies ATM signaling capability

  31. Permanent Virtual Connection (PVC) • Pre-established connections • Permanent • No Signaling required ATM Element Management System (EMS) ATM Switch ATM Switch ATM Switch ATM Switch ATM Switch

  32. Section ATM Vision Basic Setup What is ATM Physical Layer ATM Layer ATM Adaption Layer

  33. ATM Vision Basic Setup ATM Vision overview Basic System Settings ATM Settings Setting up Service Channel

  34. ATM Vision 1U 1 LEFT FAN MODULE 2 SYSTEM CONTROLLER 3 SERVICE MODULE CARRIER BOARD 4 RIGHT FAN MODULE WITH ALARM AND MODEM PORT 5 POWER SUPPLY

  35. ATM Vision 3U

  36. System Controller 1 THROW OUT HANDLES 2 ETHERNET PORT 1 (10/100 BASE T) 3 ETHERNET PORT 2 (10 BASE T) 4 NETWORK INTERFACE (HERE: STM-1 OPTICAL) 5 CASCADE INTERFACE (OPTIONAL)

  37. System Controller

  38. ATM Vision Command Line Interface • CPU: Motorola MPC860 • Operation system: Linux • Connection: 2 * Ethernet and RS232 • RS232: 19200 Baud no Parity 8 data bits 1 stop bit

  39. ATM Vision command overview

  40. ATM Vision command overview

  41. Basic System Settings Login: login: root Password: atecom Permanent system settings: sysconf ... Help on commands: sysconf ? sysconf <Command> ?

  42. Basic System Settings Show debug messages on console: debug on Changing root password: sysconf user password root IMPORTANT: DON`T FORGET THE ROOT PASSWORD !!! Notice: It´s case sensitive Setting ATM Vision hostname: sysconf net hostname <Name>

  43. Line Interface Line Terminator configuration: root@Krombacher:/> sysconf ltm ? usage: sysconf ltm sysconf ltm show sysconf ltm <interface> clk <internal|looped> sysconf ltm <interface> mode <mode> sysconf ltm <interface> cable <cable> mode: stm1: sonet, sdh e3: g.832-adm, g.751-adm, g.751-plcp ds3: cbit-plcp, m23-plcp, cbit-adm, m23-adm cable: e3: 3.5dB, 8dB, 9.9dB, 13.2dB ds3: 0-50ft, >50ft root@Krombacher:/>

  44. Line Interface Check Line Terminator configuration: sysconf ltm root@Krombacher:/> sysconf ltm LTM 0 clk looped LTM 0 mode SDH LTM 1 clk looped LTM 1 mode SDH root@Krombacher:/>

  45. ATM Settings Enable ATM networking: sysconf atm enable Check ATM status: atminfo root@Krombacher:/> atminfo Section: OOF BIP8 2975259 Line: BIP24 8976420 FEBE 2204398 Path: RDI BIP8 3553305 FEBE 2023754 ATM: TX 0 RX 40316 root@Krombacher:/>

  46. ATM Connection Direct connection between two ATM Vision (back-to-back):

  47. ATM Connection Connection between ATM Vision and a Switch

  48. ATM Connection IN OUT SiteB SiteA IN OUT root@SiteA:/> atminfo Section: LOS LOF OOF Line: AIS Path: AIS RDI ATM: TX 17 RX 0 root@SiteA:/> root@SiteB:/> atminfo Section: Line: RDI Path: RDI ATM: TX 0 RX 17 root@SiteB:/>

  49. Cascade Interface Cascading ATM Vision: Adding Service Channel without interruption PROG1 LIVE

  50. Service Channel Show hardware service channel configuration: video -c root@Krombacher:/> video -c Channel Dir Sel Type Video Mode Flags 1-0 in 00 ATecoM AUM DVB ASI auto fec 188 mpeg-fec aal5 low-prio rpga 1-1 out 00 ATecoM ADM DVB ASI packet, drop-car fec 188 204 aal5 1-3 out 01 ATecoM ADM DVB ASI packet, drop-car fec 188 204 aal5 root@Krombacher:/>

More Related