© 2007 Cisco Systems, Inc. All rights reserved.DESGN v Designing Basic Enterprise Campus Networks Describing Campus Design Considerations

© 2007 Cisco Systems, Inc. All rights reserved.DESGN v Designing an Enterprise Campus Campus design factors: Network applications characteristics Device characteristics Environmental characteristics

© 2007 Cisco Systems, Inc. All rights reserved.DESGN v Overview of Network Application Types Peer-to-peer Client-local server Client-server farm Client-enterprise edge Server

© 2007 Cisco Systems, Inc. All rights reserved.DESGN v Network Requirements of Applications Connectivity type Total required throughput High availability Total network costs

© 2007 Cisco Systems, Inc. All rights reserved.DESGN v Example: Peer-to-Peer Applications Instant messaging File sharing IP phone calls Video conference systems

© 2007 Cisco Systems, Inc. All rights reserved.DESGN v Example: Client-Local Server Applications Servers are located close to clients. Servers and clients are in the same LAN. Request to servers from nonlocal LANs is rare.

© 2007 Cisco Systems, Inc. All rights reserved.DESGN v Example: Client-Server Farm Applications Typical applications: Mail servers File servers Database servers Access to applications: Fast Reliable Controlled (security)

© 2007 Cisco Systems, Inc. All rights reserved.DESGN v Example: Client-Enterprise Edge Applications Typical applications: Internet applications –Mail servers –Web servers –Public Internet servers E-commerce applications

© 2007 Cisco Systems, Inc. All rights reserved.DESGN v Relative Network Requirements by Application Type Peer-to-Peer Client-Local Servers Client-Server Farm Client-Enterprise Edge Servers Connectivity typeSwitched Total required throughputMedium to highMediumHighMedium High availabilityLow to highMediumHigh Total network costsLow to mediumMediumHighMedium

© 2007 Cisco Systems, Inc. All rights reserved.DESGN v Environmental Characteristics for Network Design The network devices and distances between them determine the network geography. The campus network design is scoped with respect to geography: –Intrabuilding –Interbuilding –Distant remote buildings

© 2007 Cisco Systems, Inc. All rights reserved.DESGN v Intrabuilding Structure Provides connectivity inside the building Built with the building access and building distribution layers Transmission options: –Copper –Optical fiber –Wireless

© 2007 Cisco Systems, Inc. All rights reserved.DESGN v Interbuilding Structure Connectivity between buildings Distances between buildings within a few kilometers Building distribution with campus core layer Typical transmission media: optical fiber

© 2007 Cisco Systems, Inc. All rights reserved.DESGN v Distant Remote Building Structure Metropolitan-based network connectivity options: Using company-owned fiber Through enterprise WAN Through service provider offerings WAN

© 2007 Cisco Systems, Inc. All rights reserved.DESGN v Campus Transmission Media Physical media in network design influences: –Network bandwidth –Allowable distance between devices –Copper design considerations: Electromagnetic interference, grounding, security Signal attenuation, distance limitations Optical fiber design considerations: –Light signal (LED or laser) –Expensive, providing a long-term investment Wireless design considerations: –Distance, interference, bandwidth, security

© 2007 Cisco Systems, Inc. All rights reserved.DESGN v Comparison of Campus Transmission Media *Wireless is half-duplex, so effective bandwidth will be no more than one half this rate. Copper Twisted Pair Multimode FiberSingle-Mode FiberWireless BandwidthUp to10 Gbps Up to10 Gbps or higherUp to 54 Mbps* DistanceUp to 100 mUp to 2 km (Fast Ethernet) Up to 550 m (Gigabit Ethernet) Up to 300 m (10 Gigabit Ethernet) Up to 80 km (Fast Ethernet) Up to 100 m (Gigabit Ethernet) Up to 80 km (10 Gigabit Ethernet) Up to 500 m at 1 Mbps PriceInexpensiveModerateModerate to expensiveModerate

© 2007 Cisco Systems, Inc. All rights reserved.DESGN v Example: Transmission Media

© 2007 Cisco Systems, Inc. All rights reserved.DESGN v Infrastructure Device Characteristics Switches connect end devices as well as infrastructure devices: Access layer is typically data link layer switches. Distribution and core layer typically use multilayer switches. Switch type and switching layer decision is influenced by: Infrastructure services requirements(QoS, including policing, and so on) Size of the network segments Expected network failure convergence times Cost

© 2007 Cisco Systems, Inc. All rights reserved.DESGN v Example Network Service: QoS in LAN Switches Enterprise QoS guarantees that critical applications receive the required bandwidth or services.

© 2007 Cisco Systems, Inc. All rights reserved.DESGN v Summary Campus network design is influenced by several factors; first by applications characteristics, such as throughput and availability requirements. Second are environmental characteristics, such as the location of devices and buildings and transmission media. Third are infrastructure device characteristics, such switching type and support for network services.

© 2007 Cisco Systems, Inc. All rights reserved.DESGN v