Cramsession: Cisco WAN Switching Certification TM © 2001 All Rights Reserved – BrainBuzz.com 1 Contents: Contents: 1 ATM Basics 3 ATM Model 3 ATM Headers 3 ATM Addressing 5 Cisco ATM Addressing 5 ATM Adaptation Layer 5 Quality of Service 6 Service Categories 6 Frame Relay Basics 7 Voice Basics 8 Analog to Digital Conversion 9 Optimization 9 Signaling 10 General Installation 12 Tools Required 12 Installation Outline 12 Command Line Interface (CLI) 13 BPX 8600 Series 17 Card Types 17 Installing BPX Cards 17 Initial Configuration 20 IGX 8400 Series 22 Card Installation 22 Initial Configuration 26 MGX Series Installation 29 MGX 8220 29 Card Installation 30 Initial Configuration 32 MGX 8850 32 Card Installation 33 Cramsession: Cisco WAN Switching Certification TM © 2001 All Rights Reserved – BrainBuzz.com 2 MGX 8850 Interface Cards 35 Initial Configuration 38 Cisco WAN View 38 Cisco Wan Manager (CWM) 40 Components 40 Additional Features 41 Software and Firmware Upgrades 42 Downloading from CWM workstation 43 Download from a Switch 43 Cramsession: Cisco WAN Switching Certification TM © 2001 All Rights Reserved – BrainBuzz.com 3 ATM Basics ATM is a packet-switched technology based on a 53-byte packet called a cell. Each cell is divided into a 5-byte header and a 48-byte payload. The short, fixed length cell reduces delay and jitter, allowing time sensitive information such as voice and video to be transported along with data. There are various transmission media and rates available with bandwidth measured in megabits to gigabits. ATM Model ATM is based on Broadband Integrated Services Digital Network, an extension of ISDN. Similar to the OSI model, B-ISDN uses a seven-layer model. ATM redefines the lower 3 layers into the Physical Layer, the ATM Layer and the ATM Adaptation Layer. • The Physical Medium sub-layer (PMD) interfaces with the physical medium. • The Transmission Control sub-layer handles cell extraction from the data stream and error checking. ATM Headers The ATM Cell has a 5-byte header, with the remaining 48-bytes left for payload (data). Cramsession: Cisco WAN Switching Certification TM © 2001 All Rights Reserved – BrainBuzz.com 4 There are two standard headers. Cisco added an addition header type to allow for advanced ATM features. • User-to-Network Interface (UNI) header-specifies interface between a user device and a network. Note: A user device is not just a computer interface. It can be a router or switch as well. • Network-to-Network Interface (NNI) header-specifies interface between two networks. Usually a private ATM network and a public ATM network. • STI header-used between to Cisco ATM switching nodes to allow advanced network features. • Flow Control (4-bits)-a UNI field for controlling access and flow control. Usually all zeros, as there is no defined standards. • Virtual Path Indicator (VPI)-identifies the path to be taken by the ATM cell. • Virtual Circuit Indicator (VCI)-indicates the circuit number on the path. • Payload Type Indicator (PTI, 3-bits)-the type of data being carried in the payload. High order bit is 0 for user data and 1 for connection management information, second bit indicates if there was congestion, and the third bit show if user data is from customer premises equipment. • Payload Class (4-bits)-STI field indicating classes of service and BPX switch queues. • Cell Loss Priority bit (CL)-indicates the cell may be discarded if congestion is encountered. Cramsession: Cisco WAN Switching Certification TM © 2001 All Rights Reserved – BrainBuzz.com 5 ATM Addressing • VCI identifies the circuit or connection. • VPI identifies the virtual path. • The path can be seen as a trunk that carries multiple circuits between switches. • VCI is 16-bits allowing 65, 535 circuit numbers. For the STI header VCI is 8- bits for 256 circuits. • VPI is 8-bits for the UNI header, 12-bits for the NNI header (4096 paths), and 10-bits for the STI header (1024 paths). Cisco ATM Addressing Three modes available depending on the hardware being used. Addressing Node Header Type VPI/VCI Derivation Where Used BAM-BPX switch Addressing Mode STI Node derives VPI/VCI IPX switch to BPX switch, or between IPX nodes CAM-Cloud Addressing Mode UNI User defined VPI Node derived VCI Between IPX or IGX nodes and on networks switched on VPI only SAM-Simple Addressing Node UNI User defined VPI/VCI Between IPX or IGX nodes and on networks where routing is user programmed ATM Adaptation Layer • ATM Adaptation Level (AAL)-used to convert data from various sources and convert it to 48-byte segments that fit the payload of ATM cells. • Four classifications of source traffic are outlined. Traffic Class Class A Class B Class C Class D Adaptation Layer (AAL) AAL-1 AAL-2 AAL-3/4 AAL-5 AAL-3/4 Connection Mode Connection Connection Connection Connectionless End-to-End Timing Yes Yes No No Bit Rate Constant Variable Variable Variable Examples Uncompressed iCttbit Compressed Voice dVid Frame-relay, SNA, TCP /IP il SMDS Cramsession: Cisco WAN Switching Certification TM © 2001 All Rights Reserved – BrainBuzz.com 6 voice, Constant bit- rate video and Video TCP/IP, e-mail • Consists of Convergence sub-layer (CS) and Segmentation and Reassembly sub-layer (SAR). • CS receives data from the applications and sends it to the SAR to be segmented into 48-byte blocks. Quality of Service These are some of the most important QoS parameters: • Peak Cell Rate (PCR)-maximum rate a sender can send cells. • Sustained Cell Rate (SCR)-required cell rate averaged over a long interval. • Minimum Cell Rate (MCR)-minimum acceptable rate of cells per second. • Cell Loss Ratio (CLR)-the fraction of cells not delivered or delivered late. • Cell Transfer Delay (CTD)-time from source to destination (transmit time). • Cell Error Ratio (CER)-fraction of cells delivered with incorrect bits. • Cell Delay Variation (CDV or Jitter)-how regularly cells are delivered. Cells from one conversation on a multiplexed connection may be delayed while cells from another conversation are delivered. • Cell Delay Variation Tolerance (CDVT)-amount of variation in cell transmission times. Specified separately for PCR and SCR. Service Categories The ATM Forum specifies four service categories: • Constant Bit Rate (CBR)-entire connection, from source to destination, including intermediary switches, provides a set amount of bandwidth at all times. Expensive because bandwidth is reserved even if it is not used. • Variable Bit Rate (VBR)- guarantees an average bit rate over time, but allows a higher peak bit rate, with no cells lost, for a certain amount of time each minute. VBR is broken into two subclasses real time (rt) and non-real time (nrt). o rt-VBR is used for connections that require end-to-end timing, such as voice or video connections using compression or noise reduction. Cramsession: Cisco WAN Switching Certification TM © 2001 All Rights Reserved – BrainBuzz.com 7 o nrt-VBR can be used when timing relationships are not required, but QoS is still needed. • Available Bit Rate (ABR)-bit rate varies according to network conditions up to a stated maximum. Source adjusts transmission rate due to network information received from the network. • Unspecified Bit Rate (UBR)-no set bit rate guarantee. Allows a transmission rate up to a certain maximum, with no guarantee of cell loss or delivery. Frame Relay Basics Frame relay: • Defines a connection between user equipment and a WAN, not the interface or protocols of the WAN itself. Usually describes a LAN-to-LAN connection. • A standard optimized for the transport of protocol-oriented data. • Defines network paths using statistical multiplexing (creates virtual circuits). • Does not allocate bandwidth until data needs to be transmitted. • Combines packet switching and port sharing with time division multiplexing circuit switching to allow multiple point-to-point permanent virtual circuits over a single physical interface. • Operates only on the Data Link and Physical layers of the OSI model. Routing is general handled by the Network layer protocol. Components of Frame Relay • Committed Information Rate (CIR)-rate of data transfer under normal operations. Generally the contracted rate from the public service provider. CIR should never be set higher than the speed of the slowest physical connection on a VC. CIR of 0=best effort. • User-Network Interface (UNI)-describes a connection between user equipment and a frame relay network. Usually, a router (DTE) and the service provider. • Network-Network Interface-describes connection between frame relay networks. • Local Management Interface (LMI)-monitors the status of DLCIs by periodically polling the network. Can be used to exchange status information between frame devices and the network. Also supports multicasting, global addressing and flow control. Cisco switches support LMI. Cramsession: Cisco WAN Switching Certification TM © 2001 All Rights Reserved – BrainBuzz.com 8 • Bandwidth on Demand-capacity is provided as a PVC requires it up to the maximum CIR. • Flag-First and last byte of a frame, indicating the beginning and the end. There may be only one flag between frames with the end flag of one frame used as the start flag of the next. • Data Link Connection Identifier (DLCI)-10-bit routing address of the PVC at a particular UNI or NNI. Some DLCIs are reserve for signaling, management and future use so only 16 to 1007 are used to address virtual circuits. • Command/Response (C/R)-not used. Always set to 0. • Extended Address (EA)-allows the header to be lengthened to 3 or 4 bytes allowing a DLCI longer than 10-bits (more VC addresses). • Forward Explicit Congestion Notification (FECN)-set to 1 by the frame network when congestion is occurring on the packet forwarding direction of the frame. • Backward Explicit Congestion Notification (BECN)- set to 1 by the frame network when congestion is occurring on the reversed packet forwarding direction of the frame. • Discard Eligibility (DE)-set by the end node to indicate frames to be discard if congestion occurs. • Data-also called the information field. May be as large as 4,520 bytes, but is more efficient with a size of less than 4k. • Frame Check Sequence (FCS)-standard cyclic redundancy check that detects bit errors in the frame. Voice Basics Human voice can achieve a frequency of up to 4000 Hz (usually between 300 to 3000 Hz). Cramsession: Cisco WAN Switching Certification TM © 2001 All Rights Reserved – BrainBuzz.com 9 Analog to Digital Conversion • The coder-decoder (CODEC) converts analog voice signals to digital signals using pulse code modulation (PCM). • Multiple digital voice signals can be combined into a single channel using a multiplexer (MUX). The process is called Time Division Multiplexing (TDM). • A T1 connection can contain 24 channels or timeslots (called DS0s) of 64 kbps each. • An E1 or J1 connection has 30 channels with two additional timeslots for framing and signaling. Sampling • General rule is that sample rate should be twice the frequency of the signal to be sampled (example: the human voice is capable of 4000 Hz so a sample rate of 8000 samples per second would be required). • Each sample is converted into a 8 bit word (8 bits per sample x 8000 samples per sec = 64kbps). Companding • Part of the PCM process that determines the digital bits used to represent the voice signals (whether the value of a sample is a digital one or zero). • 2 companding laws: o M-law (µ-law or mu-law): logarithmic method used in North America o A-law: linear at lower levels and logarithmic at higher levels. Used in Europe, Asia, Australia and South America. • Different companding methods are not compatible (international voice traffic requires conversion from one companding method to another). Optimization Adaptive Differential Pulse Code Modulation (ADPCM) Voice Compression • Uses fewer bits than PCM sampling because only the difference between samples not the actual value of the sample amplitude is used. • Defined in ITU-T G.726 recommendation. • The following rates are available: Cramsession: Cisco WAN Switching Certification TM © 2001 All Rights Reserved – BrainBuzz.com 10 o 40 kbps using 5-bit samples o 32 kbps using 4-bit samples o 24 kbps using 3-bit samples o 16 kbps using 2-bit samples • Does not use A-law or M-law coding. • Not reliable for data or fax traffic above 4800 kbps. Code Excited Linear Prediction (CELP) Compression • Better than ADPCM at the same or higher data rate. • Uses know characteristics of human speech to provide compression. • Based on ITU-T G.729 standard. • 8, 16, 24 and 32 kbps data rates are possible. Silence Suppression • Reduces bandwidth by stopping transmission during silent periods in the voice signal. • Dependant on language spoken, silence suppression can provide 60 percent bandwidth reduction. • Algorithm analyzes the signal to determine if a signal is voice or background noise (based on known characteristics of human speech). Signaling Signaling occurs between a subscriber and a switch or a switch and a switch. Signaling is the process of sending status and control information between network elements. In voice communications, signaling is generally used to initiate a call or connection. Subscriber to switch signaling is used from handset to PBX and includes on-hook, off-hook detection and dialing. Switch to switch (or interswitch) signaling is used between the local exchange carrier (LEC) and interexchange carrier (IXC) or between PBX and PBX (or switch). Interswitch signaling is generally digital. Two types of interswitch signaling: [...]... TM Cramsession: Cisco WAN Switching Certification Single to Dual Height Slot Conversions • Begin at the left and move to the right Starting points can be slots 1 and 2 (with 17 and 18), or 9 and 10 SRM slots 15 and 16 can be converted out of sequence • After conversion the slot takes the number of the top single height slot © 2001 All Rights Reserved – BrainBuzz.com 34 TM Cramsession: Cisco WAN Switching. .. Frame Relay Connections o Connections are added using Cisco WAN manager o Frame Relay connections from IGX to BPX o ATM or Frame Relay connections from MGX to BPX o Connections are end-to-end and managed via SNMP © 2001 All Rights Reserved – BrainBuzz.com 21 TM Cramsession: Cisco WAN Switching Certification IGX 8400 Series • Multi-service switch supports WAN voice, data and video • 1 Gbps cellbus with a... manage the node using Cisco Wan manager (or the CLI) MGX 8850 MGX 8850 is an IP+ATM switch that can be used as a stand-alone device or as a feeder to a BPX 8600 series switch • As a feeder narrow-band and medium-band ATM, Frame Relay and voice into a single, wide-band ATM feeder trunk to the BPX © 2001 All Rights Reserved – BrainBuzz.com 32 TM Cramsession: Cisco WAN Switching Certification Stand-alone... that UPS meets Cisco requirements • Airflow and cooling must be suitable for the equipment being installed 2 Verify that all parts ordered are present and in good condition Record all part numbers and serial numbers © 2001 All Rights Reserved – BrainBuzz.com 12 TM Cramsession: Cisco WAN Switching Certification 3 Unpack and install the equipment in the desired rack (may be provided by Cisco or third... Alarm Relay module Front ARI Alarm Relay Interface, back card for ARM Back SCM System Clock Module, works with NPM Back Trunk cards (NNI) UXM Universal Switching Module © 2001 All Rights Reserved – BrainBuzz.com 23 Front TM Cramsession: Cisco WAN Switching Certification BC-UAI-4-155-MMF OC3/STM1, 2 or 4 port multimode or single mode fiber back card Back 3 or 6 port T3 back card with BNC connectors Back... Configure parameters Control templates-cnfict Channel utilization-cnfchutl Channel priorities-cnfchpri 11 Configure connections to access device (such as Cisco 3800) © 2001 All Rights Reserved – BrainBuzz.com 28 TM Cramsession: Cisco WAN Switching Certification o Up port to access device-upftcport o Add device to node-addad (view connected access devices with dspads) Default bandwidth parameters can... TM Cramsession: Cisco WAN Switching Certification Redundancy • Set up card redundancy-addyred (or addcdred) • Switch between active and redundant cards-resetcd • Switch between active and standby processor-switchcc BPX 8600 Series The BPX 8600 series switches are high capacity, standards based broadband ATM switches that support: • Backbone ATM • IP+ATM services • Multi Protocol Label Switching (MPLS)... card with the proper back card Installing BPX Cards • The card shelf has 15 slots numbered from left to right when viewed from the front © 2001 All Rights Reserved – BrainBuzz.com 17 TM Cramsession: Cisco WAN Switching Certification • When installing cards, follow ESD precautions • Slot 7 is reserved for BCC card Redundant nodes have a BCC card in slots 7 and 8 • Slot 15 is for the ASM/LM-ASM card pair... indicates the backplane is 19.2 Gbps capable • BCC-4 or later controller • Switch software release 8.1.18 or later • At least one BXM card © 2001 All Rights Reserved – BrainBuzz.com 18 TM Cramsession: Cisco WAN Switching Certification Table of BPX Cards Card Card Name Location BPX Common Core Group BPX-BCC-32 Broadband controller card, can be installed in redundant pairs Uses System Software ver 7.0 and... BPX-MMF-155-4-BC BPX-SMF-155-4-BC BPC-SMFLR-155-4-BC BPX-MMF-155-8-BC BPX-SMF-155-8-BC BPC-SMFLR-155-8-BC BPX-BXM-622 BPX-BXM-622-2 BPX-SMFLR-622-BC © 2001 All Rights Reserved – BrainBuzz.com 19 TM Cramsession: Cisco WAN Switching Certification BPX-XLR-622-BC 1500mm interface BPX-SMF-622-2-BC Back cards for BXM-622-2 and BME Single mode fiber, single mode, long range fiber and extra long-range fiber respectively . Cramsession: Cisco WAN Switching Certification TM © 2001 All Rights Reserved – BrainBuzz.com 4 There are two standard headers. Cisco. multicasting, global addressing and flow control. Cisco switches support LMI. Cramsession: Cisco WAN Switching Certification TM © 2001 All Rights