The Hierarchical internetworking model is a three-layer model for
network design Network planning and design is an iterative process, encompassing
topological design, network-synthesis, and network-realization, and is aimed at ensuring that a new telecommunications network or service meets the needs of the subscriber and ope ...
first proposed by
Cisco
Cisco Systems, Inc., commonly known as Cisco, is an American-based multinational digital communications technology conglomerate corporation headquartered in San Jose, California. Cisco develops, manufactures, and sells networking hardware, ...
. It divides
enterprise network
Enterprise (or the archaic spelling Enterprize) may refer to:
Business and economics
Brands and enterprises
* Enterprise GP Holdings, an energy holding company
* Enterprise plc, a UK civil engineering and maintenance company
* Enterprise ...
s into three layers: core, distribution, and access layer.
Access layer
End-stations and servers connect to the enterprise at the ''access layer''. Access layer devices are usually commodity switching platforms, and may or may not provide
layer 3
In the seven-layer OSI model of computer networking, the network layer is layer 3. The network layer is responsible for packet forwarding including routing through intermediate routers.
Functions
The network layer provides the means of transfe ...
switching services. The traditional focus at the access layer is minimizing "cost-per-port": the amount of investment the enterprise must make for each provisioned
Ethernet
Ethernet () is a family of wired computer networking technologies commonly used in local area networks (LAN), metropolitan area networks (MAN) and wide area networks (WAN). It was commercially introduced in 1980 and first standardized in 1 ...
port. This layer is also called the desktop layer because it focuses on connecting client nodes, such as workstations to the network.
Distribution layer
The distribution layer is the ''smart'' layer in the three-layer model. Routing, filtering, and
QoS policies are managed at the distribution layer. Distribution layer devices also often manage individual branch-office
WAN connections. This layer is also called the Workgroup layer.
Core layer
The core is the backbone of a network, where the internet(internetwork) gateway are located. The core network provides high-speed, highly redundant forwarding services to move packets between distribution-layer devices in different regions of the network. Core switches and routers are usually the most powerful, in terms of raw forwarding power, in the enterprise; core network devices manage the highest-speed connections, such as
10 Gigabit Ethernet
10 Gigabit Ethernet (10GE, 10GbE, or 10 GigE) is a group of computer networking technologies for transmitting Ethernet frames at a rate of 10 gigabits per second. It was first defined by the IEEE 802.3ae-2002 standard. Unlike previous ...
or
100 Gigabit Ethernet
40 Gigabit Ethernet (40GbE) and 100 Gigabit Ethernet (100GbE) are groups of computer networking technologies for transmitting Ethernet frames at rates of 40 and 100 gigabits per second (Gbit/s), respectively. These technologies offer significantly ...
.
See also
*
Multi-tier architecture
In software engineering, multitier architecture (often referred to as ''n''-tier architecture) is a client–server architecture in which presentation, application processing and data management functions are physically separated. The most wide ...
*
Service layer
In intelligent networks (IN) and cellular networks, service layer is a conceptual layer within a network service provider architecture. It aims at providing middleware that serves third-party value-added services and applications at a higher ap ...
References
*
* {{citation , url=http://www.cisco.com/c/en/us/td/docs/solutions/Enterprise/Campus/HA_campus_DG/hacampusdg.html , title=High Availability Campus Network Design , accessdate=2022-04-05
Computer_networking
Reference models