With the rising demands of the converged network, the recent developments in network design are the Cisco Borderless Network. The Cisco Borderless Network is a network design that allows organizations to support a borderless network that can connect any person, everywhere on any device very securely and consistently. This design address IT and business challenges.
The Cisco Borderless Network structure merge wired and wireless access, as well as access control, policy; and performance management of different device types. Using the Cisco Borderless Network architecture is built on a hierarchical infrastructure of hardware that is scalable and flexible, the Figure below illustrates the Cisco Borderless Network which provides two primary sets of services: network services and endpoint services; all services managed by an integrated management solution. This design enables different network elements to work mutually and also allow to access resources from any place at any time; as providing optimization, scalability as well as security.
Hierarchy in the Cisco Borderless Network
Availability, flexibility, security, and manageability is the primary requirement of the borderless switched network. The borderless switched network should deliver current and future requirement. The basic principles of the Borderless switched network are the following:
- hierarchical network Design
Understanding the principle to fits in the different situation is very important. The hierarchical borderless
switched network is providing a base for the network designer to cover security, mobility, and unified communication features. Cisco designs three-tier and two-tier hierarchical network for a campus. The figure below illustrates the Cisco hierarchical network design. The three-tier of this design are the access, distribution, and core layers. Every layer of this design can be seen as a clear structured module with particular roles and functions in the campus network.
The campus hierarchical network design which containing modularity provide critical network services with resilient and flexible. The modularity also provide assistance for increase and change that occurs over time
Access, Distribution, and Core Layers
The access layer is the place where traffic enters or exits the campus network. It is the edge of the campus network. Usually, the main function of an access layer is to provide network connectivity and access to end users. The switches of the access layer connect to switches of the distribution layer. The switches in the distribution layer apply network foundation technologies such as routing, QoS, and security.
To meet user requirement and network application, the next-generation switching platforms currently present extra converged integrated; and quick services to different types of endpoints at the edge of the network. Creating intelligence into the switches of an access layer allows applications to function on the network more capable and securely.
The distribution layer provides connectivity between access layer and core layer with many important functions. This layer provides intelligent switching and routing. The distribution layer provides network access policy functions to access the whole network as long as differentiated services to different classes of service applications at the edge of the network. This layer providing high ease of use throughout redundant distribution layer switches to the end-user and equal cost paths to the core layer. The distribution layer also aggregate large-scale wiring closet networks and aggregate Layer 2 broadcast domains and Layer 3 routing boundaries
This layer is the backbone of the Cisco borderless network. The core layer connects a number of layers of the campus network and work as the aggregator for all of the other campus blocks and interconnects the campus with each other inside the network. The core layer main function is to provide speedy fault isolation and high-speed backbone connectivity.
Collapsed Core Network
Three-tier campus network usually planed for organizations where the access, distribution, and core, each are required as separate layers. This is required because of a basic, cost-effective, scalable, and efficient physical layout design for the large-scale network where many campuses exist. The best practice is to make an extended-star
physical topology from the main campus to all other campuses.
The campus where fewer users accessing the network or single building campus usually not required a separate core and distribution layers. Network structure required in this situation is called a collapsed network or two-tier campus network. In a collapsed network the role of the core switches moves to the distribution switches, merging the core- and distribution layer.
The figure below illustrates the collapsed campus network example for where the distribution and core layers are collapsed into a single layer.