1.The Open Systems Interconnect (OSI) model has seven layers.The model partitions a communication system into abstraction layers. The original version of the model defined seven layers.OSI means Open Systems Interconnectionis reference model for how applications can communicate over a network This article describes and explains them, beginning with the lowest in the hierarchy the physical and proceeding to the highest the application. The layers are stay in this way: Application Presentation Session Transport Network Data Link Physical features osi model: If network communications need to happen with out any trouble, many problems must be solved. Coordinating all these problems are so complex and not easy to manage. Big picture of communication over network is understandable through this OSI model. We can understand new technologies as they are developed. Troubleshooting is easier by separate network. 2. the Data process that takes placethe message from one host to another cab be done as such: The data to be passed from one host to another can be composed at the first top layer of the passing device layer N into a protocol data unit. The protocal data unit is passed to next layer, where it is known as the service data unit. At next layer let us consider that layer be N-1 the service data unit is observed the with a header,a footer,some times both,producing a layer next protocal data unit. It is then passed to layer next layer N-2. The process repeated until reaching the lower level,from which the data is transmitted to the receiving device. At the receiving device the data is passed from the lowest to the highest layer as a series of SDUs while being successively stripped from each layer\'s header and/or footer, until reaching the topmost layer, where the last of the data is consumed. 3. ISO 1.OSI is a generic, protocol independent standard, acting as a communication gateway between the network and end user. 2.OSI is a conceptual model that characterizes and standardizes the communication functions of a computing or telecommunication system irrespective of their underlying structure and technology being used. 3.OSI is a reference model. 4.The OSI model consists of 7 architectural layers TCp/IP 1. TCP/IP model is based on standard protocols around which the Internet has developed. It is a communication protocol, which allows connection of hosts over a network. 2.TCP/IP is a core protocol of the Internet Protocol Suite (IPS). It is the basic communication language or protocol of the internet. It can be used as a communications protocol in a private network either an intranet or an extranet 3.TCP/IP is an implementation of OSI model. 4.The tcp/ip can contains only 4 laters 4.1.network inerface layer:The most widely-known Application layer protocols are those used for the exchange of user information. 2.internet layer:The Internet layer is responsible for addressing, packaging, and routing functions. The core protocols of the Internet layer are I.

1. 1.The Open Systems Interconnect (OSI) model has seven layers.The model partitions a
communication system into abstraction layers. The original version of the model defined seven
layers.OSI means Open Systems Interconnectionis reference model for how applications can
communicate over a network This article describes and explains them, beginning with the lowest
in the hierarchy the physical and proceeding to the highest the application. The layers are stay in
this way:
Application
Presentation
Session
Transport
Network
Data Link
Physical
features osi model:
If network communications need to happen with out any trouble, many problems must be
solved. Coordinating all these problems are so complex and not easy to manage.
Big picture of communication over network is understandable through this OSI model.
We can understand new technologies as they are developed.
Troubleshooting is easier by separate network.
2.
the Data process that takes placethe message from one host to another cab be done as such:
The data to be passed from one host to another can be composed at the first top layer of the
passing device layer N into a protocol data unit.
The protocal data unit is passed to next layer, where it is known as the service data unit.
At next layer let us consider that layer be N-1 the service data unit is observed the with a
header,a footer,some times both,producing a layer next protocal data unit. It is then passed to
layer next layer N-2.
The process repeated until reaching the lower level,from which the data is transmitted to the
receiving device.
At the receiving device the data is passed from the lowest to the highest layer as a series of
SDUs while being successively stripped from each layer's header and/or footer, until reaching
the topmost layer, where the last of the data is consumed.
3.
ISO
1.OSI is a generic, protocol independent standard, acting as a communication gateway between

2. the network and end user.
2.OSI is a conceptual model that characterizes and standardizes the communication functions of
a computing or telecommunication system irrespective of their underlying structure and
technology being used.
3.OSI is a reference model.
4.The OSI model consists of 7 architectural layers
TCp/IP
1. TCP/IP model is based on standard protocols around which the Internet has developed. It is a
communication protocol, which allows connection of hosts over a network.
2.TCP/IP is a core protocol of the Internet Protocol Suite (IPS). It is the basic communication
language or protocol of the internet. It can be used as a communications protocol in a private
network either an intranet or an extranet
3.TCP/IP is an implementation of OSI model.
4.The tcp/ip can contains only 4 laters
4.1.network inerface layer:The most widely-known Application layer protocols are those used
for the exchange of user information.
2.internet layer:The Internet layer is responsible for addressing, packaging, and routing
functions. The core protocols of the Internet layer are IP, ARP, ICMP, and IGMP.
3.transport layer:The Transport layer also known as the Host-to-Host Transport layer is
responsible for providing the Application layer with session and datagram communication
services.
4.Application Layer:The Application layer provides applications the ability to access the
services of the other layers and defines the protocols that applications use to exchange data.
5.
Layer 2 switches operate using the data link layer addresses.Traditional switching operates at
layer 2 of the OSI model, where packets are sent to a specific switch port based on destination
MAC addresses. Link-layer, hardware, or MAC-layer addresses identify individual devices.
Most hardware devices are permanently assigned this number during the manufacturing
process.Large layer 2 broadcast domains can be susceptible to certain unintended problems, such
as broadcast storms, which have the ability to cause network outages.
Layer 1, also referred to as the Physical Layer, describes the electrical interface and isn't of
much interest to switch vendors.Switches operating at Layer 2 are very fast because they’re just
sorting MAC addresses, but they do not look at the Layer 3 portion of the packet to learn
anything more.
Layer 3 intelligent packet forwarding (routing) based on Layer 3 information is traditionally the
function of routers.Layer 3 switches use network or IP addresses that identify locations on the

3. network. A location can be a LAN workstation, a location in a computer’s memory, or even a
different packet of data traveling through a network.A Layer 3 switch is basically a switch that
can perform routing functions in addition to switching. A client computer requires a default
gateway for layer 3 connectivity to remote subnets.you can think of the layer 3 engine being
integrated into the switch itself.
Switches operating at Layer 3 take more time examining packets than Layer 3 devices and
incorporate routing functions to actively calculate the best way to send a packet to its destination.
Solution
1.The Open Systems Interconnect (OSI) model has seven layers.The model partitions a
communication system into abstraction layers. The original version of the model defined seven
layers.OSI means Open Systems Interconnectionis reference model for how applications can
communicate over a network This article describes and explains them, beginning with the lowest
in the hierarchy the physical and proceeding to the highest the application. The layers are stay in
this way:
Application
Presentation
Session
Transport
Network
Data Link
Physical
features osi model:
If network communications need to happen with out any trouble, many problems must be
solved. Coordinating all these problems are so complex and not easy to manage.
Big picture of communication over network is understandable through this OSI model.
We can understand new technologies as they are developed.
Troubleshooting is easier by separate network.
2.
the Data process that takes placethe message from one host to another cab be done as such:
The data to be passed from one host to another can be composed at the first top layer of the
passing device layer N into a protocol data unit.
The protocal data unit is passed to next layer, where it is known as the service data unit.
At next layer let us consider that layer be N-1 the service data unit is observed the with a
header,a footer,some times both,producing a layer next protocal data unit. It is then passed to

4. layer next layer N-2.
The process repeated until reaching the lower level,from which the data is transmitted to the
receiving device.
At the receiving device the data is passed from the lowest to the highest layer as a series of
SDUs while being successively stripped from each layer's header and/or footer, until reaching
the topmost layer, where the last of the data is consumed.
3.
ISO
1.OSI is a generic, protocol independent standard, acting as a communication gateway between
the network and end user.
2.OSI is a conceptual model that characterizes and standardizes the communication functions of
a computing or telecommunication system irrespective of their underlying structure and
technology being used.
3.OSI is a reference model.
4.The OSI model consists of 7 architectural layers
TCp/IP
1. TCP/IP model is based on standard protocols around which the Internet has developed. It is a
communication protocol, which allows connection of hosts over a network.
2.TCP/IP is a core protocol of the Internet Protocol Suite (IPS). It is the basic communication
language or protocol of the internet. It can be used as a communications protocol in a private
network either an intranet or an extranet
3.TCP/IP is an implementation of OSI model.
4.The tcp/ip can contains only 4 laters
4.1.network inerface layer:The most widely-known Application layer protocols are those used
for the exchange of user information.
2.internet layer:The Internet layer is responsible for addressing, packaging, and routing
functions. The core protocols of the Internet layer are IP, ARP, ICMP, and IGMP.
3.transport layer:The Transport layer also known as the Host-to-Host Transport layer is
responsible for providing the Application layer with session and datagram communication
services.
4.Application Layer:The Application layer provides applications the ability to access the
services of the other layers and defines the protocols that applications use to exchange data.
5.
Layer 2 switches operate using the data link layer addresses.Traditional switching operates at
layer 2 of the OSI model, where packets are sent to a specific switch port based on destination
MAC addresses. Link-layer, hardware, or MAC-layer addresses identify individual devices.

5. Most hardware devices are permanently assigned this number during the manufacturing
process.Large layer 2 broadcast domains can be susceptible to certain unintended problems, such
as broadcast storms, which have the ability to cause network outages.
Layer 1, also referred to as the Physical Layer, describes the electrical interface and isn't of
much interest to switch vendors.Switches operating at Layer 2 are very fast because they’re just
sorting MAC addresses, but they do not look at the Layer 3 portion of the packet to learn
anything more.
Layer 3 intelligent packet forwarding (routing) based on Layer 3 information is traditionally the
function of routers.Layer 3 switches use network or IP addresses that identify locations on the
network. A location can be a LAN workstation, a location in a computer’s memory, or even a
different packet of data traveling through a network.A Layer 3 switch is basically a switch that
can perform routing functions in addition to switching. A client computer requires a default
gateway for layer 3 connectivity to remote subnets.you can think of the layer 3 engine being
integrated into the switch itself.
Switches operating at Layer 3 take more time examining packets than Layer 3 devices and
incorporate routing functions to actively calculate the best way to send a packet to its destination.