Hello Aspirants,as we all know only few days are left for IBPS SO exam.So, we are starting a new series ” Gem points ” in this regard.learn them by heart.Share and discuss in comment section.We will gear up level day by day starting from very basics.So,Put your Seatbelts on and join us in the journey to be a specialist officer.
1) The physical layer concerns with bit-by-bit delivery.. Data format is bits.
2)optical fiber transmission media has the highest transmission speed in a network.
3)Bits can be send over guided and unguided media as analog signal by digital modulation.
4)The portion of physical layer that interfaces with the media access control sublayer is called physical signalling sublayer..
5)physical layer provides
~mechanical specifications of electrical connectors and cables
~electrical specification of transmission line signal level
~specification for IR over optical fiber.
6)In asynchronous serial communication the physical layer provides
~start and stop signalling
7)The physical layer is responsible for
8)The physical layer translates logical communication requests from the data link layer into hardware specific operations.
9) A single channel is shared by multiple signals by multiplexing.
10)Wireless transmission can be done via
Data Link Layer
1)Date format if FRAMES.The data link layer takes the packets from network layer and encapsulates them into frames for transmission.
2)tasks done by data link layer are
3)media access control sublayer of the data link layer performs data link functions that depend upon the type of medium.
4)Header of a frame generally contains
5)Automatic repeat request error management mechanism is provided by logical link control sublayer.
6)When 2 or more bits in a data unit has been changed during the transmission, the error is called burst error.
7)CRC stands for cyclic redundancy check.
8)The technique of temporarily delaying outgoing outgoing acknowledgements so that they can be hooked onto the next outgoing data frame is called piggybacking.