Kudler Fine Foods Network Review And Proposal

Introduction

Kudler Fine is evaluating their current network and creating a logical design document that will show what needs to be done to upgrade or install a new network system to meet the goals set out to achieve. The list of goals presented by Kudler management is as follows:

 Faster Checkout Response

 Collect Customer Data

 Track Customer Data and Purchases

 Ensure the security of their customers personal data

Review of Current Network

The current network is a fairly early design called an Ethernet Bus network. A bus network Topology is an architecture in which a set of clients are connected via a shared communications line, called a bus. Each of the 3 sites utilizes the same configuration of servers, workstations, standalone UPS and a 56k modem which are connected to an Ethernet backbone. Bus networks are difficult to troubleshoot because if the backbone goes down then every piece of hardware on the wire is affected. If one user is sending a signal on the network simultaneous to another user, the signals will collide causing a drop to both signals. These networks usually will be in a listening state to ensure no others are sending packets at the same time, this type of collision detection is called, carrier sense multiple access with collision detection (CSMA/CD).

Network Topology

Each of the La Jolla and Del Mar sites both have the same architecture, which is 1 Ethernet backbone connecting 3 servers, 4 workstations, 1 printer and external CD burner connected point to point to a server, and one standalone UPS. The Encinitas site is similar in design, but downsized as it still has 1 Ethernet backbone connecting 4 workstations, 1 server, and 1 standalone UPS.

Logical Topology

Each site of Kudler Fine Foods depends on one Novell server and one 56K modem for network communications. This means that should one of the 56K modems go down, the site is unable to communicate data with either of the other sites. Also, if one of the network servers were to go down, all network communications within that site would go down. There are backup modem devices at each site to deal with modem failure. However, Kudler does not at this time employ the use of backup Novell servers to ensure network communications within the LAN.

Network Protocols

The Kudler Fine Foods network is based on a Novell Netware environment. Each site has a Novell 4.11 server which provides remote file access, printer sharing, and support for various applications such as electronic mail transfer and database access. Netware specifies the upper five layers of the OSI reference model and runs on any layer 2 media access protocol. Netware's client/server architecture supports remote access through the use of remote procedure calls. A remote procedure call begins when the local computer sends a procedure call to the remote server. The server then executes the remote procedure call and returns the requests information to the local client.

There are four major protocols supported in the Novell Netware suite. The Internetwork Packet Exchange (IPX) protocol exists at layer 3 of the OSI model. When a device to be communicated with is located on a different network, IPX routes the information to the destination through any intermediate networks. The Sequenced Packet Exchange (SPX) protocol also exists at layer 3 of the OSI model for reliable, connection-oriented datagram transmission. The Network Core Protocol (NCP) is a series of server routines designed to process application requests coming from the Netware shell. Services provided by NCP include file access, printer access, name management, security, and file synchronization. NetBIOS, or Network Basic Input/Output System, is a session-layer interface specification from IBM and Microsoft. Netware's NetBIOS emulation software allows programs written to the industry-standard NetBIOS interface to run within the Netware system.

Netware also includes several application layer services. Netware Message Handling Service is a message delivery system that provides electronic mail transport. Btrieve is Novell's implementation of the binary tree database access mechanism. Netware Loadable Modules are implemented as add-on modules that attach into the Netware system.

Figure 1. The Netware protocol suite relation to the OSI reference model (Netware, n.d.).

Reliability and Uptime

Network reliability is the ability of a network to maintain or restore an acceptable level of performance during network failures by application various restoration techniques and prevention of service outages from network failures by applying preventative techniques. (Network Survivability, 2001). Computing the reliability of a network is quite difficult; therefore estimation by means of simulation is a popular choice for determining network reliability.

System Response Time

System response time is the interval between the instant a request is entered which requires a response from a remote networked node and the instant that response is received. Most of the network nodes on the system are Pentium II PC's with Windows 98 operating systems. There is one Pentium III Windows NT server located at Del Mar and La Jolla. Del Mar and La Jolla employ the use of one print server at each location, while the Encinitas location does not.

The 56K modem between sites severely impacts the system response time for Kudler's network nodes. Information that is traveling across sites at that low of a speed means that response times are going to be rather lengthy. The limited processing power of each of the network nodes and servers also severely impacts system response time.

Bandwidth Usage

Bandwidth is the maximum amount of data that can travel a communications path in a given time, usually measured in bits per second. Inbound traffic is data that is received by a computer, while outbound traffic is data that is sent from a computer. Using the bandwidth estimation tool located at www.webuser.co.uk/bandwidthcalculator.php, it is estimated that average bandwidth usage for 12 users over the WAN is approximately 1688Mb per week. This number is assuming 12 hours of web surfing, 12 high-quality photos sent/received, 24 low-quality photos sent/received, 12 short video clips watched, 96 hours of online radio, and 360 emails