network delay throughput and end to end performance notes

Chapter Roadmap: Network Delay and Throughput

@keyframes fadeSlideUp { from { opacity: 0; transform: translateY(15px); } to { opacity: 1; transform: translateY(0); } } .anim-step { opacity: 0; animation: fadeSlideUp 0.6s ease-out forwards; } .anim-step-1 { animation-delay: 0.2s; } .anim-step-2 { animation-delay: 0.5s; } Network Delay, Throughput & Performance Mastering the mathematics of data movement. Your Learning Journey 1 Store-and-Forward & Bottleneck Throughput Understand how routers process packets, the concept of store-and-forward delay, and how the slowest link determines the maximum throughput of a path. High Importance 2 Transmission and Propagation Delay Distinguish between the time to push bits onto the link and the time for signals to travel through the medium. Master the total delay formula. Core Concept

Store-and-Forward Transfer and Bottleneck Throughput

Store-and-Forward & Bottlenecks How routers process packets and why the slowest link defines your speed. Context Computer Networks › Network Delay and Throughput › Store-and-Forward Transfer What you will learn here The mechanism of store-and-forward switching in routers. How to calculate total transfer time for single and multiple packets. The concept of bottleneck bandwidth and its effect on end-to-end throughput. Solving multi-hop transfer problems with pipelining effects.

The Store-and-Forward Mechanism

The Store-and-Forward Mechanism Store-and-Forward is the fundamental switching technique used in modern packet-switched networks. 1. Receive: The router receives the incoming packet bit-by-bit and stores it completely in an input buffer. 2. Process: Once the entire packet is received, the router checks for errors, examines the destination address, and consults its routing table. 3. Forward: The router moves the packet to the appropriate output buffer and begins transmitting it onto the next link. Key Consequence: A router cannot transmit the first bit of a packet until it has received the last bit of that same packet. This introduces a store-and-forward delay at every intermediate hop. T_{s t or e} = \frac{L}{R} Where L is packet size in bits and R is link bandwidth in bps.

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Network Delay, Throughput and End-to-End Performance Notes for GATE CS

Network Delay, Throughput and End-to-End Performance notes for GATE CS: 16 study cards covering concepts, formulas, shortcuts and exam traps, plus solved practice questions.

Chapter Roadmap: Network Delay and Throughput

Network Delay, Throughput & Performance

Mastering the mathematics of data movement.

Your Learning Journey

Store-and-Forward & Bottleneck Throughput

Understand how routers process packets, the concept of store-and-forward delay, and how the slowest link determines the maximum throughput of a path.

High Importance

Transmission and Propagation Delay

Distinguish between the time to push bits onto the link and the time for signals to travel through the medium. Master the total delay formula.

Core Concept

Store-and-Forward Transfer and Bottleneck Throughput

Store-and-Forward & Bottlenecks

How routers process packets and why the slowest link defines your speed.

Context

Computer Networks › Network Delay and Throughput › Store-and-Forward Transfer

What you will learn here

The mechanism of store-and-forward switching in routers.
How to calculate total transfer time for single and multiple packets.
The concept of bottleneck bandwidth and its effect on end-to-end throughput.
Solving multi-hop transfer problems with pipelining effects.

The Store-and-Forward Mechanism

Store-and-Forward is the fundamental switching technique used in modern packet-switched networks.

1. Receive: The router receives the incoming packet bit-by-bit and stores it completely in an input buffer.

2. Process: Once the entire packet is received, the router checks for errors, examines the destination address, and consults its routing table.

3. Forward: The router moves the packet to the appropriate output buffer and begins transmitting it onto the next link.

Key Consequence: A router cannot transmit the first bit of a packet until it has received the last bit of that same packet. This introduces a store-and-forward delay at every intermediate hop.

T_{s t or e} = \frac{L}{R}

Where $L$ is packet size in bits and $R$ is link bandwidth in bps.

Bottleneck Throughput

In a multi-hop path, the end-to-end throughput is determined by the bottleneck link—the link with the lowest bandwidth.

Bottleneck Bandwidth Definition

R_{b o ttl e n ec k} = min (R_{1}, R_{2}, \dots, R_{n})

Why? Data cannot arrive at the destination faster than it can traverse the slowest segment. Faster upstream links will simply cause packets to queue up at the router preceding the bottleneck link.

Link 1

10 Mbps

→

Link 2

2 Mbps

→

Link 3

5 Mbps

Maximum throughput across this path is 2 Mbps.