Chapter 11 Enterprise Networks

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Chapter 11Enterprise Networks Internet

• Enterprise Network Architecture
• Internet
• Enterprise Network Internet

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Enterprise Network Architecture

• Overview
• Logical Design
• Physical Design

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Overview

• Virtual corporation
• Virtual private network or enterprise network
• Virtual LAN
• Technology
• LAN switches
• ATM switches
• Backbone routers
• SONET

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Overview

• Application
• Collaborative computing application software
• Intelligent gent-based software
• Data distributed database

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Virtual LANs Logical Design

• Use LAN switch with software
• Types
• Layer 2 virtual LAN (switch)
• Layer 3 virtual LANs (routing switches)
• Pro
• Lower cost of constantly changing and moving
  workstations
• Limitations
• Broadcasting and multicasting to its members
• Hard to manage (switching)
• No filtering for security
• No standard and interoperability

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Virtual LANs Logical Design

• Transmission alternatives
• Signaling message (broadcasting address)
• Frame tagging (address tag)
• Time division multiplexing (bandwidth)
• IEEE 802.10encryption, authentication,
  segmentation, reassembly
• Bandwidth Hierarchy
• Distributed backbones bridge
• Collapsed backbones router with numerous
  internetworking modules and enormous bandwidth
  capacity

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Physical Design ATM LAN emulation

• ATM address resolution
• LAN emulation client (LEC) software
• ATM-to-LAN conversion devices
• convert Ethernet, token ring or FDDI into fixed
  length ATM cells
• Unicast (point-to-point) transmission
• LAN emulation server (LES) software
• LES configuration services
• LES broadcast and unknown services (BUS)
• LES emulation services (address resolution
  protocol)

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Physical Design ATM LAN emulation

• Pros
• support multiple network layer protocols between
  virtual LANs
• Cons
• Flat network topoloty
• Broadcast storms
• No filtering for security

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Protocols over ATM Network

• Classical IP over ATM
• Logical IP subnet or LIS within subnet
• Needs ATM address resolution protocol (ATMARP)
• Multiprotocol over ATM (MPOA)
• Edge devices
• Route server
• IP switching
• Long file use layer 2
• Short message uses layer 3

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Internet Survey

• 72 enhance company image
• 22 financially rewarding
• 40 financial rewards after 12-24 months
• Less 6 using credit card transaction
• 11 million Internet users
• 200 million television viewers

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Business Objectives Internet

• Customer service
• Marketing opportunity
• Competitive pressure
• Financially profitable

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Internet Services/Resources

• World Wide Web
• Information servers
• FTP servers
• Gopher servers
• WAIS servers
• USENET servers
• Global e-mail

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World Wide Web

• Web browsers
• Web site
• Graphical or multimedia

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Information Servers

• Telnet TCP/IP
• FTP servers file transfer protocol
• Gopher
• Search engines
• Text
• WAIS (wide aarea information services)
• USENET servers Network new transport protocol
  (NNTP)

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Global E-Mail

• List server
• Electronic magazines (E-zines

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Internet Pro Con

• Pro
• Access
• Bandwidth
• Front-end tools
• Server tools
• Information
• Con
• Security
• Bandwidth
• search
• Ownership
• Regulation

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Internet Connectivity

• Internet access providers (IAP) or Internet
  connectivity providers (ICP)
• Internet presence provider (IPP)
• Network access device
• Modem
• CSU/DSU
• Router

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WWW Connectivity Alternatives

• Web browser
• Mosaic
• Internet Explorer
• Netscape
• Web terminology
• Hypertext transport protocol (HTTP)
• Hypertext markup language (HTML)
• Uniform resource locator (URL)

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Web Browser Selection Criteria

• Vertical integration e-mail
• Ease of setup and use
• Performance
• Horizontal integration network attached resources

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Internet E-Mail Gateways

• Translator
• Simple mail transport protocol (SMTP)
• No foreign character
• Limited file size
• No executable file
• Multiple Internet mail extension (MIME)

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Internet Gateway vs. Internet-Enable Clients

• Internet gateway
• Pros single location, easy management
• Cons bottleneck
• Internet-enabled clients
• Pro not bottleneck
• Cons configuration, software, LAN protocol

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Internet/Web Server Analysis

• Link to Internet
• IP address (IAP or InterNIC)
• Server hardware
• CPU 120MHz Pentium
• Storage RAID
• Bus PCI
• Memory 128 MB
• Network interface card 100-Mbps Ethernet
• High-end UNIX workstation

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Internet/Web Server Analysis

• Server software
• Web page input form (common gateway interface
  CGI)
• Gateway file transfer
• Security
• Management monitoring reporting

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Assignment

• Review chapters 9-11
• Read chapter 12