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.BXM-622 Broadband Switch Module An OC-12c/STM-4 version of the BXM interface card, which supportsOC-12/STM-4 native ATM access and trunk ports for the BPX switch.Itoperates at the SONET/SDH rate of 622.08 Mbps.One- or two-port versionsof the card are available; both can be configured for either trunk or accessapplication.The BXM cards support ATM-Frame Relay internetworking and service internetworking.They also allow you to configurePVCs or SVCs for the following defined service classes:Constant Bit Rate (CBR)Variable Bit Rate-Real Time (VBR-RT)Variable Bit Rate-Non-Real Time (VBR-NRT)Unspecified Bit (UBR)Available Bit Rate (ABR)The BPX with Stratm architecture supports up to 16 independent classes of service, thereby protecting your hardwareinvestment as the industry defines additional traffic types.AXIS Interface ShelfThe AXIS interface shelf enables the BPX Service Node to support a wide range of user services.AXIS modules adaptincoming data to 53-byte ATM cells using industry-standard ATM adaptation layers (AALs) for transport over the ATMnetwork.Because the AXIS interface shelf will support a range of services from a single platform, organizations can reduce equipmentcosts, fully utilize their investments in existing premises equipment, and rapidly deploy new services as required.Services below 34 Mbps are provisioned on the AXIS shelf, and the following interfaces are supported:Frame RelayHigh-speed Frame RelayATM Frame UNISMDST1/E1 ATM UNIn x T1/E1 inverse multiplexing for ATM (IMATM) UNICircuit emulationISDN switched accessEach AXIS shelf aggregates traffic from as many as 80 T1 or E1 ports onto a single port of the multiport broadband interfacecard.This high-port density maximizes use of the BPX high-capacity switch fabric.A compact footprint minimizes the spacerequired within central offices.Each 9-inch, rack-mounted shelf supports more than 2,000 64-Kbps users.http://www.cisco.com/cpress/cc/td/cpress/ccie/ndcs798/nd2008.htm (30 of 38) [9/16/2000 5:09:34 PM]Designing ATM InternetworksCisco/StrataCom IGX Family of SwitchesFor wide-area networking, LAN data flowing between different enterprise sites is aggregated by the router and then mixedwith voice and other legacy data streams across the corporate wide-area backbone.Traditionally, these corporate backbonesuse TDM technology.However, as the use of LAN data has exploded and older TDM equipment has been fully depreciated,newer solutions can be cost justified.Enterprises are increasingly turning to a new public service officers (for example, VPN,Frame Relay, and intranets) and a new generation of Frame Relay/ATM-based enterprise switches to maximize the efficiencyand minimize the cost of their networks.The Cisco/StrataCom IGX family of switches provides the needed linkage to integrate the high-speed LAN data and thelower-speed voice and legacy data across the enterprise backbone in the most cost-effective manner.The IGX family ofswitches is specifically designed for enterprise integration.The IGX family of ATM enterprise WAN switches includes the IGX8 (8-slot switch), the IGX16 (16-slot switch), and IGX32(32-slot switch).The IGX family can provide the following enterprise WAN support:Voice---UVM and CVMLegacy data---HDM and LDMATM---ALMFrame Relay---UFM and FRMTrunks---NTM, BTM, and ALMBenefits of the IGXWith the IGX switch, you can leverage ATM to save costs as follows:Apply utilization rates in your network design to source PVCsCombine multiple networks into one multiservice networkOptimize the transmission network with design toolsFor example, you can use StrataView+, a network management tool, for network discovery.You can also use theConfiguration Extraction Tool (CET) to populate the design data set with existing facilities.With such design tools,incremental network design is possible.In addition to lower costs of networks, other major benefits of deploying the IGX in an enterprise internetwork include thefollowing:Multiband/multiserviceBetter application performanceReliabilityInvestment protectionSample IGX ConfigurationThis section provides an example of how IGX switches can be deployed in an enterprise internetwork.In this example, a postalservice has 180,000 employees and 180 mail-sorting offices.The current network design, which is a TDM network, has 750LANs, 350 routers, 220 X.25 switches, and 110 PBXs.The network handles approximately 70 million voice minutes of trafficper year.Currently, the enterprise is confronted with the following problems with the existing network design and networkrequirements:Poor performance on the existing TDM networkExponential growth of LAN trafficMany new applicationsInability of the existing WAN to scale uphttp://www.cisco.com/cpress/cc/td/cpress/ccie/ndcs798/nd2008.htm (31 of 38) [9/16/2000 5:09:34 PM]Designing ATM InternetworksFigure 8-21 shows an example of how the IGX switches can be deployed throughout the network to address these problems.Figure 8-21: Example of an IGX deployment [ Pobierz całość w formacie PDF ]