How to find End-to-End Delay

 

End-to-End Delay (also known as one-way delay) refers to the time taken for a packet to be transmitted across a network from source to destination. It’s an essential metric in network performance analysis. Let’s break it down:

1. Components of End-to-End Delay:

   • Transmission Delay: The time taken to push all the bits of a packet onto the link.
   • Propagation Delay: The time taken for a signal to travel from the sender to the receiver.
   • Processing Delay: The time spent by routers and switches to process the packet.
   • Queuing Delay: The time spent waiting in queues at intermediate nodes.

2. Calculating End-to-End Delay:

   • The end-to-end delay of a single packet can be approximated as half of the round-trip time (RTT). However, this assumes symmetric paths, which may not always be the case.
   • For more accurate measurement, you can directly measure the one-way delay between two points A and B using synchronized clocks. A timestamp is recorded on the packet at A, sent to B, and the receiving time is noted. The difference gives the one-way delay.

3. Assume data travels through the links at the speed of light . Problem 

1 (a) What is the transmission delay if 
• A sends a 500 byte packet to B 
• B sends a 125 byte packet to D 

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1. Identifying Problems:

   • If you observe unusually high end-to-end delays, consider the following:
     • Congestion: Network congestion can cause queuing delays.
     • Link Failures: Broken links or misconfigured routers can lead to delays.
     • Packet Loss: Lost packets need retransmission, increasing delay.
     • Uneven Paths: Asymmetric paths can cause variations in delay.

Remember that end-to-end delay depends on various factors, and accurately identifying the problem requires analyzing network behavior, monitoring tools, and understanding the specific context.