Q3 Transport Layer

Reliable, connection-oriented communication

Flow control and congestion avoidance

Low-latency, unreliable communication

Error detection and correction

UDP

TCP

SCTP

ICMP

To route packets between networks

To establish, manage, and terminate connections between applications

To ensure reliable delivery of data between hosts

To encode and decode data for transmission over the network

IP

TCP

ICMP

ARP

No acknowledgment of data delivery is required

Data can be transmitted without establishing a session

A logical connection is established before data transfer begins

Each data packet is treated independently of others

64 bytes

512 bytes

1024 bytes

65535 bytes

Connection-oriented communication

Reliable data delivery

Lower overhead

Congestion control mechanisms

Slow start

Flow control

Congestion avoidance

Selective acknowledgment

To identify the source and destination ports

To indicate the length of the TCP header

To specify the size of the data payload

To order and reassemble segments at the receiver

The sequence number of the next byte the sender expects to receive

The sequence number of the last byte received correctly

The size of the sender's receive window

The maximum segment size supported by the sender