Transport Layer

Question 1

Which osi layer is responsible for end to end the communication and flow control

Answer 1

Transport layer

Question 2

Pdu at layer 4

Answer 2

Segments or datagram

Question 3

Two main protocols at layer 4

Answer 3

TCP on udp

Question 4

What makes TCP connection oriented

Answer 4

Establishes connection first using the three-way handshake (SYN ,SYN-ACK , ACK)

Question 5

Order of the TCP three-way handshake

Answer 5

SYN SYN-ACK ACK

Question 6

Three big things TCP guarantees that udp does not

Answer 6

Reliable delivery,ordered delivery , error checking/ retransmission

Question 7

Udp is best for what kind of applications

Answer 7

Speed-critical/ loss tolerant streaming , VoIP , online gaming

Question 8

What does TCP use to put segments back in the correct order

Answer 8

Sequence numbers

Question 9

What does TCP use to control how much data the sender can send

Answer 9

Window size / sliding window (flow control)

Question 10

What does TCP do when it detects lost or corrupted segments

Answer 10

Retransmits them

Question 11

Port number are added at which layer

Answer 11

Layer 4

Question 12

Firewalls that filter by port numbers operate primarily at which layer

Answer 12

Layer 4

Question 13

TCP vs UDP , what does TCP have that UDP doesnt

Answer 13

Handshake , ACKs and retransmission

Question 14

Protocol used for DNS queries by default

Answer 14

UDP port 53(fast) - falls back to TCP if response is too big

Question 15

Which Protocol does HTTPS run on top of

Answer 15

TCP port 443