midterm Flashcards
How many layers OSI Model have?
7 Layers
Specified in ISO _____
7498
Relates to Communication Technology
Layers 1 to 4
Relates to User Application
Layers 5-7
Represents services that directly support software applications for file transfers, database access, and electronic mail etc.
Application Layer 7
Related to representation of transmitted data
–Translates different data representations from the Application layer into uniform standard format
•Providing services for secure efficient data transmission
–e.g. data encryption, and data compression.
Presentation Layer 6
Allows two applications on different computers to establish, use, and end a session.
–e.g. file transfer, remote login
•Establishes dialog control
–Regulates which side transmits, plus when and how long it transmits.
•Performs token management and synchronization.
Session Layer 5
Manages transmission packets
–Repackages long messages when necessary into small packets for transmission
–Reassembles packets in correct order to get the original message.
•Handles error recognition and recovery.
Transport Layer 4
Manages addressing/routing of data within the subnet
–Addresses messages and translates logical addresses and names into physical addresses.
–Determines the route from the source to the destination computer
–Manages traffic problems, such as switching, routing, and controlling the congestion of data packets.
Network Layer
Packages raw bits from the Physical layer into frames (logical, structured packets for data).
·Provides reliable transmission of frames
·It waits for an acknowledgment from the receiving computer.
·Retransmits frames for which acknowledgement not received
Data Link Layer 2
Transmits bits from one computer to another
•Regulates the transmission of a stream of bits over a physical medium.
•Defines how the cable is attached to the network adapter and what transmission technique is used to send data over the cable.
Physical Layer 1
_____ devices are products used to connect networks
Internetworking
Local Area Network and Devices
- Bridge
- Hub
- Ethernet Switch
- Router
- ATM switch
Wide Area Networks and Devices
- Router
- ATM Switch
- Modem
- Comm. Server
______ can provide a simple solution if either of these two problems exists.
When signals first leave a transmitting station, they are clean and easily recognizable.
Repeater