Which OSI layer needs to be addressed to resolve the pr…

A newly implemented IP-based video conferencing application is causing the network to slow down. Which OSI layer needs to be addressed to resolve the
problem?

A.
Layer 1

B.
Layer 2

C.
Layer 3

D.
Layer 4

E.
Layer 5

F.
Layer 6

G.
Layer 7

Explanation:
You need to address Open System Interconnect (OSI) Layer 1, the Physical layer, to resolve the problem. IP-based video conferencing applications are bandwidthintensive and may cause the network to slow down unless there is enough bandwidth to ensure proper network operation. To resolve bandwidth problems, you may
need to switch to a higher capacity network backbone, whichmay require a change of cabling or media types, such as fiber optics. Cabling and network media types
are defined at OSI Layer 1.
The seven layers of the OSI model are as follows, in descending order from Layer 7 to Layer 1:
– Application: Interacts directly with the application. It provides application services, such as e-mail and File Transfer Protocol (FTP).
– Presentation: Enables coding and conversion functions for application layer data. The Presentation layer converts data into a format that is acceptable by the
application layer. The formatting and encryption of data is done at this layer.
– Session: Creates, manages, and terminates sessions between communicating nodes. The session layer handles the service requests and responses that take
place between different hosts.
– Transport: Delivers data sequentially and without errors. This layer manages data transmission between devices, a process known as flow control. The Transport
layer protocols are Transmission Control Protocol (TCP) and User Datagram Protocol (UDP).
– Network: Defines the network address or the Internet Protocol (IP) address, which is then used by the routers to forward the packets.
– Data Link: Ensures the reliable delivery of data to the physical address of the destination.
– Physical: Describes the physical medium used to convert the data to bits. Examples include fiber optic, wireless, and Ethernet.
Objective:
Network Fundamentals
Sub-Objective:
Apply troubleshooting methodologies to resolve problems

http://docwiki.cisco.com/wiki/Internetworking_Basics#OSI_Model_and_Communication_Between_Systems