What are the main network architecture models?
- Three main models:
- –Peer-to-peer (P2P)
- –Client/server (C/S)
- –Directory services
- Hybrid model
- –Combines peer-to-peer & client/server
List the common server types.
- Files server
- Print server
- Messaging server
- Application server
- Web server
Describe files servers
–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.
Describe print servers
–The print servers stores the print jobs in a print queue until a printer is available.
Describe Messaging servers
–Manage and route email messages.
Describe Application servers
- –Database servers–Business
- -specific applications
Describe Web servers
- –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.).
Describe Peer-to-peer networking:
- –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.
Advantages of peer-to-peer networks:
- –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
Disadvantages of peer-to-peer networks:
- –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
What are things to consider when choosing a P2P network
- 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
Describe main characteristics of Client/Server Networks.
- 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.
Client/Server Networks Advantages:
- 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.
Client/Server Networks Disadvantages:
- 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)
A Single-Server Network
- 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
A Multiserver 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
- -Cloud based
- Model can be expanded by connecting individual LANs
Microsoft’s directory-based network architecture is called
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
Directory Services Network Characteristics:
- 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.
Directory Services Networks Advantages:
- Greater flexibility
- Enhanced management capabilities
- Enhanced security
- Manufacturers are phasing out support for more traditional client/server networking models
Directory Services Networks DisAdvantages:
- Administrators must have proper education
- Number of management/design options can be confusing
- One domain controller must run at all times
Hybrid network architectures
- 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.
Hybrid Architectures Advantages:
- 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.
Hybrid Architectures Disadvantages
- 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.