Flow control is a technique that allows two stations working at different speeds to communicate with each other. It is a set of measures taken to regulate the amount of data that a sender sends so that a fast sender does not overwhelm a slow receiver.In data link layer, the sender continues to send frames only after it has received acknowledgments from the user for the previous frames. This is called feedback based flow control. Here, a restriction is imposed on the number of frames the sender can send before it waits for an acknowledgment from the receiver.Feedback based Flow ... Read More

Flow control is a technique that allows two stations working at different speeds to communicate with each other. It is a set of measures taken to regulate the amount of data that a sender sends so that a fast sender does not overwhelm a slow receiver. In data link layer, flow control restricts the number of frames the sender can send before it waits for an acknowledgment from the receiver.Approaches of Flow ControlFlow control can be broadly classified into two categories −Feedback based Flow Control In these protocols, the sender sends frames after it has received acknowledgments from the user. ... Read More

Error control in data link layer is the process of detecting and correcting data frames that have been corrupted or lost during transmission.In case of lost or corrupted frames, the receiver does not receive the correct data-frame and sender is ignorant about the loss. Data link layer follows a technique to detect transit errors and take necessary actions, which is retransmission of frames whenever error is detected or frame is lost. The process is called Automatic Repeat Request (ARQ).Phases in Error ControlThe error control mechanism in data link layer involves the following phases −Detection of Error − Transmission error, if ... Read More

High-level Data Link Control (HDLC) is a group of communication protocols of the data link layer for transmitting data between network points or nodes. Since it is a data link protocol, data is organized into frames. A frame is transmitted via the network to the destination that verifies its successful arrival. It is a bit - oriented protocol that is applicable for both point - to - point and multipoint communications.Transfer ModesHDLC supports two types of transfer modes, normal response mode and asynchronous balanced mode.Normal Response Mode (NRM) − Here, two types of stations are there, a primary station that ... Read More

Point - to - Point Protocol (PPP) is a communication protocol of the data link layer that is used to transmit multiprotocol data between two directly connected (point-to-point) computers. It is a byte - oriented protocol that is widely used in broadband communications having heavy loads and high speeds. Since it is a data link layer protocol, data is transmitted in frames. It is also known as RFC 1661.Services Provided by PPPThe main services provided by Point-to-Point Protocol are −Defining the frame format of the data to be transmitted.Defining the procedure of establishing link between two points and exchange of ... Read More

Framing is a Data Link layer function whereby the packets from the Network Layer are encapsulated into frames. The data frames can be of fixed length or variable length. In variable - length framing, the size of each frame to be transmitted may be different. So, a pattern of bits is used as a delimiter to mark the end of one frame and the beginning of the next frame.The two types of variable - sized framing are −Character-oriented framingBit - oriented framingCharacter - Oriented FramingIn character - oriented framing, data is transmitted as a sequence of bytes, from an 8-bit ... Read More

The differences between byte stuffing and bit stuffing can be done under the following heads −What are byte stuffing and bit stuffing?Byte stuffing is a mechanism to convert a message formed of a sequence of bytes that may contain reserved values such as frame delimiter, into another byte sequence that does not contain the reserved values.Bit stuffing is the mechanism of inserting one or more non-information bits into a message to be transmitted, to break up the message sequence, for synchronization purpose.Purposes of byte stuffing and bit stuffingIn Data Link layer, the stream of bits from physical layer are divided ... Read More

DefinitionBit stuffing is the mechanism of inserting one or more non-information bits into a message to be transmitted, to break up the message sequence, for synchronization purpose.Purpose of Bit StuffingIn Data Link layer, the stream of bits from the physical layer is divided into data frames. The data frames can be of fixed length or variable length. In variable - length framing, the size of each frame to be transmitted may be different. So, a pattern of bits is used as a delimiter to mark the end of one frame and the beginning of the next frame. However, if the ... Read More

Binary is the simplest kind of number system that uses only two digits of 0 and 1 (i.e. value of base 2). Since digital electronics have only these two states (either 0 or 1), so binary number is most preferred in modern computer engineer, networking and communication specialists, and other professionals.Whereas Hexadecimal number is one of the number systems which has value is 16 and it has only 16 symbols − 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 and A, B, C, D, E, F. Where A, B, C, D, E and F are single bit representations ... Read More

Whereas Hexadecimal number is one of the number systems which has value is 16 and it has only 16 symbols: 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 and A, B, C, D, E, F. Where A, B, C, D, E and F are single bit representations of decimal value 10, 11, 12, 13, 14 and 15 respectively. Whereas Decimal system is most familiar number system to the general public. It is base 10 which has only 10 symbols: 0, 1, 2, 3, 4, 5, 6, 7, 8 and 9.Conversion from Hexadecimal to Decimal number systemThere are various ... Read More