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This chapter introduces Cisco's product line and provides the following information:
Cisco Systems designs and produces communications products to build multiprotocol, multimedia, multivendor networks. With Cisco Systems products, network managers can interconnect terminals, workstations, computer systems, and different networks to create networks of networks.
Products from Cisco Systems solve the problems of complex internetworks by supporting multiprotocol, multimedia, multivendor networks. Even organizations that do not yet require a complex wide area network (WAN) can connect existing equipment with Cisco Systems products to form a network of any size. With Cisco Systems products, network growth plans need not depend on a single topology, protocol, transmission medium, or vendor.
The key device for building a trouble-free WAN is a Cisco Systems network server. A Cisco Systems network server is a dynamic router that provides a wide variety of network management capabilities in addition to the multiprotocol, multimedia, multivendor internetworking already described.
Just as in interconnecting local area networks (LANs), Cisco Systems network servers help build WANs that achieve the interoperability and connectivity large organizations need. Network servers from Cisco Systems support computers and networking equipment from all vendors, using all available media and virtually any protocol.
A WAN that uses Cisco Systems network servers is both more cost-effective and more efficient. Cisco Systems network servers help organizations take advantage of all their existing computers and networking equipment. The dynamic routing of the network servers ensures that network traffic reaches the intended addresses promptly, regardless of different protocols, equipment from different vendors, and ongoing network configuration changes.
A WAN interconnects LANs, host computers, and public and private networks into a communications network that spans a large geographic area. After organizations have become accustomed to the benefits of LANs, they often want to extend their networking capabilities by internetworking different LANs or connecting remote sites to large networks.
An organization may already own hundreds of microcomputers and mainframes manufactured by different vendors, as well as several different kinds of LANs such as Ethernet and Token Ring. Depending on its networking needs, the organization may consider using the following devices to extend its network:
Complex internetworks have grown past the point where they can depend on equipment from a single vendor. Virtually all organizations connecting LANs and creating WANs today have major commitments to hardware and software from many different vendors. Therefore, current and future internetworking requires products that support multiprotocol, multimedia, and multivendor networks.
Routers from Cisco Systems help LANs and WANs achieve interoperability and connectivity. They operate with equipment from all vendors over most available media. This section describes Cisco-supported protocols and media, as well as the capabilities of Cisco Systems routers for routing, network management, and network security.
Large organizations need the flexibility that multiprotocol networks give them to communicate with diverse hardware and software from many vendors. Cisco Systems routers support many networking protocols, as well as several specific routing protocols for compatibility with other networks. Included are protocols based on open standards and proprietary protocols from a variety of vendors.
One Cisco Systems router can forward packets concurrently from any combination of the following networking protocols:
For convenient access to existing networks, Cisco Systems network servers support these industry standard networking media:
Network servers from Cisco Systems support synchronous serial circuits at many speeds. Customers may use 9.6 and 19.2 kilobits-per-second synchronous serial service, and 56 kilobits-per-second service for medium-traffic connections.
For fast serial service over routes with heavy data needs, Cisco's full duplex, High Speed Serial Interface (HSSI) is capable of transmitting and receiving data at up to 52 Mbps, and supports connectivity to T3, E3, SMDS at DS-3 and other high speed wide area services.
Cisco Systems network servers support T1 circuits at 1,544 kilobits per second, T1C circuits at 3,088 kilobits per second, and British Telecom Megastream and CEPT circuits at 2,048 to 4,096 kilobits per second.
Cisco Systems markets a broad line of synchronous serial media adapters, including RS-232, V.35, and RS-449 to allow their routers to convert to equipment such as modems and DSUs that utilize these interfaces.
Transferring data among networks is the primary task of a network server, a task whose efficiency requires up-to-date information about network status. Dynamic network routing, used by Cisco Systems routers, automatically responds to network changes to ensure faster, more reliable packet routing. Continually updated information enables the routers to find the most reliable links and routes with fastest transmission.
A Cisco Systems router monitors traffic on each network link connected to it, and routes the traffic to the appropriate destinations. Because the router is an "intelligent" router, it sends each network segment only the packets destined for it. No segment is burdened by unnecessary traffic.
The Interior Gateway Routing Protocol (IGRPTM), developed by Cisco Systems for
TCP/IP and ISO CLNS, monitors the network to determine the status of each route and select the best route for each data packet. Network traffic, path reliability, and path speed all influence route selection. Cisco Systems specifically designed IGRP to address the problems of routing on complex networks with many alternative routes, built of media with diverse bandwidth and delay characteristics.
While running IGRP, Cisco Systems routers can concurrently receive and understand messages from other network segments sent using different routing protocols. For example, IP routing protocols supported by Cisco Systems, in addition to IGRP, include:
All Cisco Systems routers support the native, dynamic routing protocols used by the various supported network protocols, such as DECnet, Novell IPX, and AppleTalk. This allows compatibility with other vendor's routers. Multiple network protocols and their dynamic routing protocols operate concurrently, sharing the same router and media.
Cisco Systems provides a full range of network management tools that network managers and system administrators will find invaluable in the day-to-day operations of their networks.
Most network managers must resolve problems that arise from line failures, overloads, equipment outages (either planned or unplanned), and changes to network interconnections. With static routing tables, network managers must spend time developing and installing other routes.
With Cisco Systems' dynamic routing, routers automatically handle routing problems and optimize traffic flow. The network manager can concentrate on true management issues such as network planning, capacity management, and meeting the needs of different user groups.
With Cisco Systems' Interior Gateway Routing Protocol (IGRP), packet routing and flow optimization take place automatically. Therefore, organizations can concentrate on issues such as planning for network growth, high-level network troubleshooting, and user support.
Network servers from Cisco Systems also provide detailed network management statistics, including traffic statistics, and counts of messages transmitted and received. Remote echo and route-tracing diagnostics help network managers isolate faults and refine network measurements. Cisco Systems also supports the Simple Network Management Protocol (SNMP), the industry standard for network management.
Internet work management can be as easy as clicking a mouse button with the Cisco Systems' NetCentralTM software--a dynamic, user-configurable network map operating on a fully integrated relational database.
NetCentral is a high-performance software tool for management of multivendor internetworks. It is designed for network monitoring and in-depth network planning and analysis through use of a dynamic visual network map and integrated relational databases.
The NetCentral network map provides network managers with an instant visual status check of the entire network. Pop-up windows and icons provide real-time statistics for remote networks and devices, so that network analysts and administrators can maintain an accurate picture of their internetwork topology.
NetCentral software operates on the Sun 3/xx series, the SPARCstation workstations, and on the Solbourne workstation. Contact Cisco Systems for more information.
Network security is an increasingly important aspect of managing complex networks. Cisco Systems network servers enable network managers to implement several different security features. Optional passwords limit access to the privileged command set, as well as to console and terminal lines. Access lists restrict transmissions to only the specified addresses, whether identifying server ports, hosts, or routers.
Packet-type control specifies which packets may pass, such as mail packets, file transfers, and remote logins. This access-by-service security operates on top of access-list control for complete flexibility and security. Cisco Systems also supports DDN security options for IP packets.
As people use networks more, they come to depend on their capabilities. Network users begin to take for granted that the network will always be available. Network managers face the challenge of meeting this expectation.
At Cisco Systems, hardware reliability is a top engineering priority. Equipment failures rarely occur because all Cisco Systems products meet rigid testing standards.
If problems do occur, Cisco Systems' onboard diagnostic software helps isolate them quickly, enabling customers to identify problems and arrange repairs without being familiar with the equipment. Cisco Systems engineers are always available to help with failure diagnosis, if necessary.
Cisco Systems' standard service includes low-cost board exchange, with replacements delivered by next-day express service. A premium service contract provides 24-hour coverage throughout the continental United States. On-call, on-site service by Cisco Systems field engineers is available anywhere in the world. More information about Cisco's service and support is found in the Customer Services Product Guide.
Part of the power and flexibility of Cisco Systems product components is derived from their modular physical configuration options. Customers can choose the chassis, processor, back-panel connector mountings, and communications interfaces best suited to their network.
The chassis encloses a power supply, component cards, and a backplane. Six models are available for the network server.
For high-speed operation, the Cisco network servers use processors based on the MC68020 microprocessor. The Cisco Systems processors contain onboard RAM, system ROM holding all operating system, bootstrap, and diagnostic software, and hardware and software support for a control console.
The CSC/2 processor offers one megabyte of RAM, and is suitable for medium performance applications.
The CSC/3 is Cisco's high-end processor offering four megabytes of RAM. The additional RAM increases the size of the maximum routing table. The CSC/3 processor card provides the increased switching speeds necessary to support Cisco's high-speed network interfaces.
Cisco Systems also offers optional nonvolatile memory that retains configuration information despite power losses or system reboots. With the nonvolatile memory option, the terminal and network servers need not rely on other network servers for configuration and boot service information.
Each chassis model accepts connector panels (also referred to as appliques) in numerous formats, enabling easy configuration of network servers to meet current and future needs. Supported connectors include:
Cisco Systems offers a full range of interface options on their network interface cards:
The Cisco Modular Products Hardware Installation and Reference and the IGS Hardware Installation and Reference describe Cisco's hardware products and provides procedures for installing them into your system. Refer to these manuals for hardware-specific information.
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