NW203 Ch4_PP Architecture

• Three main models:
• –Peer-to-peer  (P2P)
• –Client/server  (C/S)
• –Directory services

• Hybrid model
• –Combines peer-to-peer & client/server

• Files server
• Print server
• Messaging server
• Application server
• Web server

–File servers offer users a central location to save files.

–The security control access to these files depends on the network architecture and server type.

–The print servers stores the print jobs in a print queue until a printer is available.

–Manage and route email messages.

• –Database servers–Business
• -specific applications

• –Virtual hosting
• One system is able to serve as a host for multiple domain names, allowing several systems to share a single IP address and the host system to share resources (e.g., memory, processor cycles, etc.).

• –Is a design where any computer can act as both server and client
• –decentralized resource sharing (files and printers)
• –Usually inexpensive
• –Typically smaller organizations(–Best suited for fewer than 12 users, Some suggest up to 20 users)
• -files are not stored in a central location
• –Allows computers (and users) to communicate easily
• -uses Workgroups

–Logical peer-to-peer grouping

–Term used most commonly to describe a peer-to-peer network.

• –Are easy to configure
• –Integrate networking software in the operating system
• –Typically do not require additional server hardware and software
• –Allow users to manage their own resources
• –Do not require a network administrator
• –Reduce total cost in comparison with other network architectures
• However, this doesn’t account for hidden costs

• –Provide limited number of connections for share resources
• –Computers with shared resources may suffer performance issues
• –Do not allow for central management
• –No central file storage
• –Require users to be responsible for managing resources
• –Offer poor security

• Budgetary constraints
• -Peer-to-peer networks are uniquely suited to situations with budgetary constraints

• Level of computer literacy
• -Users will be expected to handle their own resource sharing

• Total cost ownership
• -Hardware costs, management costs, hidden costs, etc

• A centralized model for:
• -data storage
• -Allow a high level of security based on permissions.
• -network applications
• -Managed centrally by network administrator(s)
• Also called server-based networks

Yield cost savings by centralizing resources, data and security

• Offer performance improvement over peer-to-peer networks
• -Client and server can process information simultaneously
• -Provide shared services
• -Employ specialized servers that provide services to the client workstations.
• -scalable

• Data are stored centrally and can be easily backed up.
• User accounts and security are centrally managed.
• A high level of security can be implemented at the server(s).
• Resources can be shared with multiple users.
• Server hardware and software are optimized for performance and reliability.
• Users are relieved of the burden of managing resources.

• Planning, design, and management are more complicated.
• Managing servers requires dedicated staff.
• Server software and hardware can be expensive.

Client/Server Network Security Typically allow creation of groups of users that are assigned same access permissions(GPO – Group Policy Objects)

• Used when a company outgrows its peer-to-peer network
• Server is responsible for:
• -Processing user logins
• -Handling user security
• -Acting as a file and print server
• If the server fails, so does the network

• Client/server networks based on multiple servers
• -More complex than a single-server network
• Provides better user support
• -Services are spread across multiple servers to improve performance and reliability
• -If one server fails, other servers continue to function normally or take over the malfunctioning server
• -Virtualization
• -Cloud based
• Model can be expanded by connecting individual LANs

Active Directory/Domain Services

users and computers located anywhere assigned to a domain

Responsible for maintaining the directory of network objects and managing user authentication and authorization.

: any server that is part of the domain except those that manage the directory and security functions

• Based on a model that scales.
• Domain controllers process user authentication and authorization.
• Domain centralizes security and resource management.
• Provide flexible security for shared resources.
• Provide a high level of security with detailed control.
• Are centrally managed.

• Greater flexibility
• Enhanced management capabilities
• Enhanced security
• Manufacturers are phasing out support for more traditional client/server networking models

• Administrators must have proper education
• Number of management/design options can be confusing
• One domain controller must run at all times

• A network architecture that makes use of a combination of other types of architectures.
• incorporate the best features of workgroups in peer-to-peer networks with the performance, security, and reliability of server- or directory-based networks.
• allow different standard network architectures to coexist on same network.
• provide centralized services of servers.
• allow users to share and manage own resources.

• Server applications are centrally located and managed.
• Users can assign local access to resources on their computers.
• Users can manage resources without requiring assistance from the network administrator.

• Network access can be burdensome for users.
• Users may need to remember multiple passwords.
• Files can be duplicated and changes can be overwritten.
• Files saved on the workstation are not backed up.