Metropolitan area networks (MAN). Computer and Network Examples

A Metropolitan Area Network (MAN) is a great computer network located on the large geographical area or region. It is a network bigger than Local Area Network (LAN), but territorially smaller than Wide Area Network (WAN), its diameter usually ranges from 5 to 50 kilometers. MAN usually includes several buildings or even the whole city (metropolis). It is based on high data rate compounds using the fiber channels and other digital data transmission channels. MAN includes a lot of communicating devices, for its construction are used multiple routers, switches and hubs. MAN can combine together several Local Area Networks or Campus Area Networks located in different buildings within a city and provides the Internet connectivity for them. Solutions included to Computer and Networks Area for ConceptDraw Solution Park are the real godsend for those who want design Computer Network Diagrams, and among others the Metropolitan Area Network Diagrams. They offer the libraries with ready-to-use vector design elements, professional-looking examples, samples and templates.

Components of ER Diagram

Entity-Relationship model gives the possibility to visually describe a database using the components of ER Diagram, entity relationship stencils, relationship symbols, work flow shapes. ER-diagram lets represent the data or entities, attributes of these entities and relationships between them, using standardized Crow’s Foot notation icons or Chen’s notation icons. An entity is an object of the real world, it can exist independently and has the instances which differ in attribute values (properties). The attributes give an unambiguous (uniquely) identification for the instance and are called the primary key, this key can be composite and combine several attributes. ConceptDraw DIAGRAM is a professional software available with Entity-Relationship Diagram (ERD) solution from Software Development area that lets create ERDs for various database systems, using Crow’s Foot and Chen’s notations. It is invaluable tool for software engineers and developers, it supports ODBC-compatible databases (Oracle, MySQL, MS Access, MS SQL, InterBase, Firebird and others).

ERD Symbols and Meanings

Entity Relationship Diagram (ERD) is a popular software engineering tool for database modeling and illustration the logical structure of databases, which uses one of two notations - Chen's or Crow’s Foot. Crow's foot notation is effective when used in software engineering, information engineering, structured systems analysis and design. Each of these notations applies its own set of ERD symbols. Crow's foot diagrams use boxes to represent entities and lines between these boxes to show relationships. Varied shapes at the ends of lines depict the cardinality of a given relationship. Chen's ERD notation is more detailed way to represent entities and relationships. ConceptDraw DIAGRAM application enhanced with all-inclusive Entity-Relationship Diagram (ERD) solution allows design professional ER diagrams with Chen's or Crow’s Foot notation on your choice. It contains the full set of ready-to-use standardized ERD symbols and meanings helpful for quickly drawing, collection of predesigned ERD samples, examples and templates. ConceptDraw Pro is a great alternative to Visio for Mac users as it offers more features and can easily handle the most demanding professional needs.