Data Communication & Networking (QUESTION BANK)
(CSE) Question and answer
UNIT-2
1. Illustrate Data link Layer and its sublayer in brief.
2. Design the Stop-and-Wait protocol architecture and state its working stages.
3. Define Bit stuffing? Explain its example.
4. A sender is sending data as 100100 with divisor 1101. Tabulate the CRC to send.
5. Explain burst error correction with a suitable example. Illustrate the purpose of Hamming code.
6. Elaborate the HDLC modes, HDLC frames in detail.
7. Identify the services provided by the Data Link layer and explain them in detail.
8. Design the Go-Back-N ARQ protocol architecture.
9. Distinguish between a point-to-point link and a broadcast link.
10. What are the different types of errors in data transmission?
11. What is Media Access Control (MAC)? Explain random-access protocols briefly.
12. What is parity check? Explain the working of Encoder and Decoder for a simple parity-check code.
13. A Receiver receives the codeword as 1000110 and the divisor as 1011. Find whether the data is changed during transmission or not.
14. What is Checksum? Describe the procedure to calculate the checksum in the traditional method.
15. What is chunk interleaving? How is it different from Hamming distance?
16. What is piggybacking? Explain in detail the Point-to-Point Protocol (PPP).
(NOTE: EXPLORE THIS QUESTIONS ACCORDING TO YOUR NEED)
1. Question: Illustrate Data link Layer and its sublayer in brief.
Answer:
The Data Link Layer is the second layer of the OSI (Open Systems Interconnection) model. It provides a reliable communication link between two directly connected devices over a physical medium. The Data Link Layer is divided into two sublayers: the Logical Link Control (LLC) sublayer and the Media Access Control (MAC) sublayer.
The LLC sublayer is responsible for handling the flow control, error control, and framing of data. It ensures that data packets are delivered without errors and in the correct order. The LLC sublayer also provides addressing and control mechanisms to support multiple protocols running over the same physical medium.
The MAC sublayer is responsible for controlling access to the shared physical medium. It defines protocols for addressing devices on the network and managing the transmission of data frames. The MAC sublayer implements different access control methods, such as CSMA/CD (Carrier Sense Multiple Access with Collision Detection) used in Ethernet networks.
2. Question: Design the Stop-and-Wait protocol architecture and state its working stages.
Answer:
The Stop-and-Wait protocol is a simple and reliable protocol used for communication between two devices over an unreliable channel. Here is the architecture of the Stop-and-Wait protocol and its working stages:
- Architecture:
- Sender: The sender sends a data frame to the receiver and waits for an acknowledgment (ACK) from the receiver.
- Receiver: The receiver receives the data frame, checks for errors, sends an ACK to the sender if the frame is error-free, and discards the frame if it contains errors.
- Working stages:
1. Sender sends a data frame to the receiver.
2. Sender waits for an acknowledgment (ACK) from the receiver.
3. Receiver receives the data frame.
4. Receiver checks the frame for errors.
5. If the frame is error-free, the receiver sends an ACK to the sender.
6. Sender receives the ACK.
7. If the ACK is received, the sender proceeds to send the next data frame.
8. If the ACK is not received within a specified timeout period, the sender retransmits the same data frame.
9. The process continues until all data frames are successfully transmitted and acknowledged.
The Stop-and-Wait protocol ensures reliable data transmission by using acknowledgments and retransmissions to handle errors and ensure the correct delivery of data.
3. Question: Define Bit stuffing? Explain its example.
Answer:
Bit stuffing is a technique used in data communication to ensure synchronization and avoid ambiguity in the transmission of data frames. It involves the addition of extra bits to the data stream to distinguish the data bits from control bits or special patterns.
Example:
Let's say we have a data stream that uses a start delimiter of "01111110" and an end delimiter of "01111110". The problem arises when the data itself contains a sequence that matches the delimiter. To overcome this, bit stuffing is applied.
Suppose we want to send the data "01111110 00101011 01111110" (spaces added for clarity). Without bit stuffing, the receiver may interpret the second occurrence of "01111110" as the end delimiter, even though it is part of the actual data.
To prevent this ambiguity, bit stuffing is employed. The rule is that whenever five consecutive "1" bits are encountered in the data, a "0" bit is inserted after them. So the data would be modified as follows: "01111110 00101011 11101011 01111110".
At the receiver's end, the stuffed bits are removed before processing the original data. The receiver knows that whenever five consecutive "1" bits are followed by a "0" bit, it should discard the "0" bit and continue processing the data.
Bit stuffing ensures that the original data can be accurately reconstructed at the receiver's end, even if it contains patterns that might be misinterpreted as control or delimiter sequences.
4. Question: A sender is sending data as 100100 with a divisor of 1101. Tabulate the CRC to send.
Answer: To perform CRC (Cyclic Redundancy Check) on the given data, we follow these steps:
1. Append zeros: We append the necessary number of zeros to the end of the data to match the length of the divisor. In this case, we need to append 3 zeros to "100100", making it "100100000".
2. Perform division: Divide the extended data by the divisor using binary division. Start with the leftmost bit of the dividend and keep dividing until all the bits have been processed. At each step, perform the XOR operation with the divisor if the leftmost bit is 1. The result of each XOR operation becomes the next dividend.
Dividend: 100100000
Divisor: 1101
Step 1: XOR 100100000 by 1101 (divisor)
Result: 1010 (quotient)
Remainder: 100 (partial remainder)
Step 2: Shift the remainder to the left by one bit and bring down the next bit of the dividend
Remainder: 1000
Next bit: 0
Step 3: XOR 1000 by 1101
Result: 0011 (quotient)
Remainder: 110 (partial remainder)
Step 4: Shift the remainder to the left by one bit and bring down the next bit of the dividend
Remainder: 1100
Next bit: 0
Step 5: XOR 1100 by 1101
Result: 0001 (quotient)
Remainder: 101 (partial remainder)
Step 6: Shift the remainder to the left by one bit and bring down the next bit of the dividend
Remainder: 1010
Next bit: 0
Step 7: XOR 1010 by 1101
Result: 0000 (quotient)
Remainder: 100 (partial remainder)
3. The remainder obtained at
the end of the division is the CRC. In this case, the CRC is "100".
4. The sender appends the CRC to the original data. The transmitted data becomes "100100100".
At the receiver's end, the same division is performed with the received data. If the remainder is zero, it indicates that the data has been transmitted without errors.
5. Question: Explain burst error correction with a suitable example. Illustrate the purpose of Hamming code.
Answer: Burst error correction is a technique used to correct errors that occur in a data transmission as a burst or contiguous group of errors. It is particularly effective in situations where errors tend to occur in clusters or bursts, such as in channels affected by electrical interference or fading.
Example: Let's consider a scenario where a block of data is transmitted over a communication channel, and due to noise or interference, a burst of errors occurs. For instance, the transmitted data block is "1101010101", but during transmission, a burst error affects consecutive bits, resulting in the received data being "1100011101".
To correct the burst error, error-correcting codes like the Hamming code can be used. The Hamming code adds redundant bits to the original data to create a code word. These redundant bits allow the receiver to detect and correct errors.
The purpose of the Hamming code is to provide error detection and correction capabilities. By adding parity bits at specific positions within the code word, the Hamming code enables the receiver to identify and correct single-bit errors. In the example above, if the transmitted data block was encoded using Hamming code, the receiver would detect that a burst error occurred and correct the received data to its original form, "1101010101".
The Hamming code is widely used in various applications, including memory systems, data storage, and communication protocols. It helps ensure data integrity and reliable transmission by detecting and correcting errors, thereby improving the overall accuracy of the communication system.
6. Question: Elaborate the HDLC modes and HDLC frames in detail.
Answer: HDLC (High-Level Data Link Control) is a data link layer protocol used for reliable and efficient communication between two devices. It defines different modes of operation and frame structures to support various data transfer scenarios.
HDLC Modes:
- Normal Response Mode (NRM): In NRM, one device acts as a primary station, initiating communication, while the other device serves as a secondary station. NRM supports both unidirectional and bidirectional data transfer.
- Asynchronous Balanced Mode (ABM): ABM allows both devices to function as peers, enabling bidirectional data transfer. ABM is commonly used for point-to-point communication and is widely implemented in X.25 networks.
- Asynchronous Response Mode (ARM): ARM is similar to ABM, but it supports a master-slave configuration. One device operates as the primary station, initiating communication, while the other devices act as secondary stations.
HDLC Frames:
- Flag: The frame begins and ends with a unique flag sequence, "01111110", to provide synchronization and frame delimitation.
- Address: The address field identifies the destination device or broadcast address. It can be one or more octets, depending on the addressing scheme used.
- Control: The control field contains control information, such as frame type, sequence numbers, and flow control.
- Information: The information field carries the actual data being transmitted. Its length can vary based on the implementation and requirements.
- FCS (Frame Check Sequence): The FCS field contains a cyclic redundancy check (CRC) value computed over the frame's contents. It helps detect errors during transmission.
- Flag: The frame ends with the same flag sequence, "01111110", as the beginning, marking the end of the frame.
HDLC frames can be used for both command/response scenarios and data transfer. They provide mechanisms for error detection, retransmission, and flow control, ensuring reliable and efficient data communication between devices.
Please let me know if you would like answers to the remaining questions as well.
7. Question: Identify the services provided by the Data Link layer and explain them in detail.
Answer: The Data Link layer provides several important services to ensure reliable and efficient data communication between nodes on a network. Some of the key services provided by the Data Link layer include:
1. Framing: Framing involves breaking the stream of data bits into manageable units called frames. The Data Link layer encapsulates the network layer packets into frames, adding necessary control information such as start and stop flags, addressing, and error detection to each frame. Framing allows the receiver to identify the boundaries of individual frames and extract the data correctly.
2. Physical Addressing: The Data Link layer uses physical addressing (MAC addresses) to uniquely identify devices on a network. MAC addresses are globally unique identifiers assigned to network interface cards (NICs). The Data Link layer adds the source and destination MAC addresses to the frames to ensure that they are delivered to the correct destination device.
3. Error Detection and Correction: The Data Link layer includes mechanisms for detecting and correcting errors that may occur during data transmission. Techniques such as parity checking, cyclic redundancy check (CRC), and forward error correction (FEC) are used to detect and, in some cases, correct errors in the received frames.
4. Flow Control: Flow control mechanisms are employed by the Data Link layer to regulate the flow of data between the sender and receiver. Flow control ensures that the sender does not overwhelm the receiver with data by imposing limits on the number of frames that can be sent or by using acknowledgment-based protocols.
5. Access Control: The Data Link layer is responsible for managing access to the physical medium shared by multiple devices. It determines when a device can transmit data, using various access control methods such as CSMA/CD (used in Ethernet) or token passing (used in Token Ring). These protocols prevent collisions and ensure fair access to the network medium.
6. Link Management: The Data Link layer performs link management tasks, including establishing and terminating the logical link between nodes, monitoring link status, and error recovery. It handles procedures such as link establishment, link maintenance, and link termination.
By providing these services, the Data Link layer plays a crucial role in ensuring reliable and efficient communication between network devices while abstracting the details of the underlying physical medium and network topology.
8. Question: Design the Go-Back-N ARQ protocol architecture.
Answer: The Go-Back-N Automatic Repeat Request (ARQ) protocol is a sliding window-based error control protocol used for reliable data transmission in network communication. Here is the architecture of the Go-Back-N ARQ protocol:
- Sender Side:
1. The sender divides the data to be transmitted into a series of packets.
2. The sender maintains a sending window that represents the range of sequence numbers for which acknowledgment is expected.
3. The sender sends the packets one by one in sequence, starting from the beginning of the sending window.
4. After sending each packet, the sender starts a timer.
5. If an acknowledgment for a packet within the sending window is received before the timer expires, the sender advances the window and sends the next packet.
6. If the timer expires before receiving an acknowledgment, the sender assumes that a packet or multiple packets were lost and retransmits all the packets in the current window.
7. The sender continues this process until all packets have been successfully acknowledged.
- Receiver Side:
1. The receiver maintains a receiving window that represents the range of acceptable sequence numbers.
2. The receiver receives the packets and checks for errors. If a packet is error-free, it sends an acknowledgment for that packet.
3. If an out-of-sequence packet is received, it is discarded, and the receiver does not send an acknowledgment.
4. The receiver keeps track of the expected sequence number and
only delivers in-sequence packets to the higher layers.
5. If a packet is lost or damaged during transmission, the receiver discards it and does not send an acknowledgment.
6. The receiver's acknowledgment serves as a cumulative acknowledgment, indicating the highest sequence number received correctly.
The Go-Back-N ARQ protocol ensures reliable data transmission by allowing the sender to continue sending a window of packets without waiting for individual acknowledgments. If any packet within the sending window is lost, the sender retransmits all the packets from that point onward, effectively "going back" in the sequence.
This protocol provides efficiency by allowing pipelining of packets and reducing the number of acknowledgments required. However, it also introduces additional delay due to retransmissions when errors occur.
Please let me know if you would like answers to the remaining questions.
9. Question: Distinguish between a point-to-point link and a broadcast link.
Answer: Point-to-point link and broadcast link are two different types of communication links used in networking. Here's how they differ:
Point-to-Point Link:
- A point-to-point link establishes a direct connection between two devices, allowing communication between them.
- It is a dedicated link that provides a dedicated communication channel between the two connected devices.
- Point-to-point links typically use a physical medium, such as cables or fiber optics, to establish the connection.
- Communication on a point-to-point link is typically unicast, meaning data is sent from one device to another.
- Examples of point-to-point links include Ethernet connections between two computers or a serial connection between a computer and a modem.
Broadcast Link:
- A broadcast link allows one device to send data to multiple devices simultaneously.
- It is a shared link where multiple devices are connected, and data sent by one device is received by all other devices on the link.
- Broadcast links are commonly used in local area networks (LANs) where devices need to communicate with each other.
- Communication on a broadcast link is typically multicast or broadcast, meaning data is sent to all devices on the link or a specific group of devices.
- Examples of broadcast links include Wi-Fi networks, where a wireless access point broadcasts data to all connected devices, or Ethernet networks using a hub, where data sent by one device is received by all connected devices.
In summary, a point-to-point link provides a dedicated connection between two devices, enabling direct communication, while a broadcast link allows one device to send data to multiple devices simultaneously on a shared link.
10. Question: What are the different types of errors in data transmission?
Answer: During data transmission, various types of errors can occur, affecting the integrity and accuracy of the transmitted data. The different types of errors in data transmission include:
1. Single-Bit Error: A single-bit error occurs when only one bit in a data unit is altered due to noise, interference, or transmission issues. For example, a "0" bit may be flipped to "1" or vice versa.
2. Burst Error: A burst error refers to a cluster or group of consecutive bits that are corrupted or altered during transmission. Burst errors often occur due to channel impairments like electrical noise, interference, or fading. The length of the burst indicates the number of consecutive bits affected.
3. Random Error: A random error occurs when multiple bits in a data unit are changed or corrupted independently and randomly. Random errors can be caused by various factors, such as background noise or signal distortion.
4. Insertion Error: An insertion error happens when additional bits are inserted into the transmitted data by mistake. This can occur due to synchronization issues or other transmission errors, resulting in the receiver misinterpreting the received data.
5. Deletion Error: A deletion error occurs when bits are missing or deleted from the transmitted data. Similar to insertion errors, deletion errors can happen due to synchronization problems or transmission issues, leading to data loss or corruption.
6. Substitution Error: A substitution error, also known as a transposition error, takes place when bits are replaced or interchanged within the transmitted data. This can occur due to signal interference or improper synchronization between sender and receiver.
7. Frame Error: A frame error indicates that the received frame is damaged or corrupted, making it unreadable or unusable. Frame errors can result from various transmission problems, including noise, collisions, or synchronization issues.
8. Control Error: A control error occurs when errors affect the control information within a data frame or packet. This can disrupt the proper functioning of protocols, leading to issues such as incorrect sequence numbers or erroneous flow control.
Detecting and correcting these errors is a crucial aspect of data communication, and various error control techniques, such as error detection codes (e.g., parity check, CRC) and error correction codes (e.g., Hamming code, Reed-Solomon code), are employed to ensure the accuracy and reliability of transmitted data.
11. Question: What is Media Access Control (MAC)? Explain random-access protocols briefly.
Answer: Media Access Control (MAC) is a sublayer of the Data Link layer in the OSI model. It is responsible for managing access to the shared communication medium, such as a network cable or wireless channel, when multiple devices are connected to it.
Random-access protocols are a class of MAC protocols that allow multiple devices to contend for access to the shared medium without any predetermined order. Here are two commonly used random-access protocols:
1. Carrier Sense Multiple Access (CSMA):
- CSMA is a random-access protocol that employs a "listen before talk" strategy.
- Before transmitting data, a device using CSMA first checks if the communication medium is idle (i.e., no other device is transmitting).
- If the medium is idle, the device can start transmitting. However, if the medium is busy, the device waits for a random time and then retries.
- CSMA suffers from the "hidden terminal problem," where two devices located far from each other may not detect each other's transmissions and may cause collisions.
2. Carrier Sense Multiple Access with Collision Detection (CSMA/CD):
- CSMA/CD is an improvement over CSMA that adds collision detection capabilities.
- In addition to carrier sensing, CSMA/CD devices listen to the medium while transmitting to detect if a collision occurs (i.e., if multiple devices transmit simultaneously and their signals interfere).
- If a collision is detected, the colliding devices stop transmission, wait for a random backoff time, and then retransmit.
- CSMA/CD is commonly used in Ethernet LANs, where devices connected to a shared medium must contend for access.
Random-access protocols allow devices to share the medium fairly, but they do not guarantee collision-free transmission. When collisions occur, the protocols employ backoff mechanisms to minimize the probability of subsequent collisions.
It's worth noting that there are other MAC protocols as well, such as Token Passing (used in Token Ring networks) and Reservation-based protocols (used in wireless networks). These protocols utilize different strategies for managing medium access and provide alternatives to random-access methods.
12. Question: What is parity check? Explain the working of Encoder and Decoder for a simple parity-check code.
Answer: Parity check is a basic error detection technique used to ensure the integrity of transmitted data. It involves adding an additional bit, called a parity bit, to a data unit to make the total number of 1s in the unit either even or odd. The parity bit can be used to detect errors during transmission.
The working of an Encoder and Decoder for a simple parity-check code is as follows:
Encoder:
1. The encoder takes the original data, which can be a sequence of bits, bytes, or other data units.
2. It counts the number of 1s in the original data.
3. Based on the count, the encoder adds an additional bit, the parity bit, to the data unit.
- If the count of 1s is already even, the parity bit is set to 0, making the total count of 1s even.
- If the count of 1s is odd, the parity bit is set to 1, making the total count of 1s odd.
4. The resulting data unit with the added parity bit is transmitted.
Decoder:
1. The decoder receives the transmitted data unit, which includes the original data and the parity bit.
2. It counts the number of 1s in the received data unit, including the parity bit.
3. If the count of 1s, including the parity bit, is even, the decoder assumes no error and accepts the received data.
4. If the count of 1s, including the parity bit, is odd, the decoder detects an error in the received data.
- The error could be a single-bit error if the received parity bit is flipped, or it could be a burst error if multiple bits are corrupted.
5. The decoder can request retransmission or take corrective measures based on the error detection result.
The simple parity-check code can detect single-bit errors, but it cannot correct them. It provides basic error detection capabilities and is relatively simple to implement. However, it has limitations and is not suitable for more robust error detection and correction requirements.
More advanced error detection and correction techniques, such as cyclic redundancy check (CRC) or Hamming codes, are used in practical applications to provide more reliable and efficient error control in data communication systems.
13. Question: A Receiver receives the codeword as 1000110 and the divisor as 1011. Find whether the data is changed during transmission or not.
Answer: To determine whether the data is changed during transmission using the given codeword and divisor, we can perform a process called CRC (Cyclic Redundancy Check).
1. Write the codeword and divisor in binary form:
Codeword: 1000110
Divisor: 1011
2. Perform the CRC division:
- Align the divisor (1011) with the leftmost 1 of the codeword (1000110).
- Perform a bitwise XOR operation between the divisor and the aligned portion of the codeword.
- Write the result below the aligned portion of the codeword.
- Shift the divisor one bit to the right and repeat the XOR operation until all bits of the codeword are processed.
Codeword: 1000110
Divisor: 1011
-----------------
Result: 1101
Remainder: 011
3. Check the remainder:
- If the remainder is all zeros (000), it indicates that no errors occurred during transmission, and the data is unchanged.
- If the remainder is not all zeros, it suggests that errors occurred during transmission, and the data might have been changed.
In this case:
- The remainder is 011, which is not all zeros.
- Therefore, the data is changed during transmission.
Based on the CRC calculation, we can conclude that the received codeword (1000110) has errors, and the data has been altered during transmission.
14. Question: What is Checksum? Describe the procedure to calculate checksum in the traditional method.
Answer: A checksum is an error detection technique used to verify the integrity of data during transmission. It involves generating a sum or a hash value from the data and appending it to the transmitted message. The receiver can then calculate the checksum again and compare it with the received checksum to detect errors.
The procedure to calculate a checksum in the traditional method is as follows:
1. Divide the data into fixed-size blocks or chunks. The size of each block depends on the specific checksum algorithm used.
2. Add all the values in each block together using binary addition. If the sum exceeds the maximum value that can be represented by the checksum size, wrap around the excess bits.
3. Take the complement (one's complement) of the final sum. This involves flipping all the bits from 0 to 1 and from 1 to 0.
4. The resulting value is the checksum.
To verify the integrity of the received data, the receiver follows these steps:
1. Divide the received data into the same fixed-size blocks.
2. Add all the values in each block, including the received checksum, using binary addition.
3. If the sum, including the received checksum, is zero, it indicates that no errors occurred during transmission, and the data is intact.
4. If the sum is nonzero, it suggests that errors might have occurred during transmission, and the data could be corrupted.
The checksum provides a simple and fast way to detect errors, but it does not provide error correction capabilities. It can detect errors such as single-bit flips or some burst errors, but it is not as robust as more advanced error detection and correction techniques like CRC or Hamming codes.
15. Question: What is chunk interleaving? How is it different from Hamming distance?
Answer: Chunk interleaving is a technique used in data communication to mitigate the effects of burst errors during transmission. It involves rearranging or reordering the transmitted data into different chunks or blocks before sending them over the communication channel. The reordered chunks are then received and rearranged back into their original order at the receiving end.
The purpose of chunk interleaving is to disperse burst errors that may affect consecutive bits or blocks of data. By rearranging the data into non-consecutive chunks, the impact of burst errors is spread out, and the chances of successfully recovering the original data at the receiver are increased. This technique is particularly effective in scenarios where burst errors are common, such as in wireless or noisy communication channels.
On the other hand, Hamming distance is a concept used in error detection and correction codes, such as Hamming codes. It refers to the number of bit positions in which two binary strings of the same length differ from each other. The Hamming distance is used to measure the similarity or dissimilarity between two bit strings.
In the context of error detection and correction, the Hamming distance is utilized to determine the minimum number of bit errors required to transform one valid code word into another valid code word. This property allows Hamming codes to detect and correct a specific number of bit errors in a received code word.
While both chunk interleaving and Hamming distance are techniques used in the realm of data communication and error handling, they serve different purposes. Chunk interleaving is primarily aimed at spreading out burst errors to improve error recovery, while Hamming distance is used to measure the dissimilarity between two bit strings and enable error detection and correction.
16. Question: What is piggybacking? Explain in detail the Point-to-Point Protocol (PPP).
Answer: Piggybacking is a technique used in data communication to optimize the use of network resources and reduce overhead by combining multiple types of information within a single transmission. It involves embedding one set of data within another, taking advantage of the unused or idle space in the transmission.
In the context of networking, piggybacking commonly refers to the practice of combining acknowledgment messages (ACK) with data frames. Instead of sending separate ACK frames to acknowledge the receipt of data frames, the acknowledgments are piggybacked onto the next outgoing data frame. This allows for more efficient use of the network bandwidth and reduces the number of transmitted frames.
The Point-to-Point Protocol (PPP) is a widely used data link layer protocol that provides a standard method for establishing and maintaining a direct connection between two network nodes over various physical mediums. PPP is often used in dial-up connections, as well as in network connections between Internet Service Providers (ISPs) and their customers.
PPP operates in three phases: Link Establishment, Authentication, and Network Layer Protocol Negotiation. Here's a detailed explanation of each phase:
1. Link Establishment:
- The PPP link begins with a link establishment phase, where the sender and receiver negotiate the parameters of the communication link.
- During this phase, the sender sends Link Control Protocol (LCP) packets to the receiver to establish and configure the link. The receiver responds with LCP packets to confirm the link establishment.
- Once the link is established, the sender and receiver move to the authentication phase.
2. Authentication:
- In the authentication phase, the sender and receiver authenticate each other's identities to ensure secure communication.
- Authentication protocols such as Password Authentication Protocol (PAP) or Challenge Handshake Authentication Protocol (CHAP) are used to verify the identities and credentials of both ends of the link.
- Once the authentication is successful, the sender and receiver proceed to the network layer protocol negotiation phase.
3. Network Layer Protocol Negotiation:
- In this phase, the sender and receiver negotiate the network layer protocol to be used for data transmission.
- The Link Control Protocol (LCP) packets are exchanged to determine the network layer protocol, such as Internet Protocol (IP), that will be encapsulated within PPP for data transmission.
- Once the network layer protocol is agreed upon, the PPP link is fully established, and the sender and receiver can exchange data using the chosen network layer protocol.
PPP provides features such as error detection, compression, and encryption. It supports multiple network layer protocols, making it flexible and widely compatible with various networking technologies.
