A Simple Deterministic Queueing Model

Queues can be studied with a simple deterministic model. A Deterministic queueing model helps to learn about the dynamics of a packet in a network. This model defines these functions: – A(t):  the cumulative number of bits (or bytes) that ... Read More »

Playback Buffers

most applications (web browsing, file transfer…) don’t care about the variation of the end-to-end delay. Real-time applications are impacted by variations of the end-to-end delay packet switches have buffers. End host real-time applications have playback buffers. These applications build playback ... Read More »

Go Back N Protocol and Selective Repeat

Let’s define some terms first: outstanding segments = the segments that are sent and still not acknowledged Base: the sequence number of the oldest unacknowledged packet NextSeqNum: the sequence number of the first next packet to be sent N: the ... Read More »

TCP Sliding Window

the purpose of the Sliding Window is not flow control; it is to keep track of bytes/packets sent, received, ACKd, written, read, expected,…on the sender and the receiver uses the concept of pipelining: sending a bunch of segments without waiting ... Read More »

Throughput, Goodput And Latency

To define Throughput, Goodput and Latency, we need to understand some terms first. Propagation Delay The propagation delay can be calculated with the following formula: Propagation delay = distance / speed of the signal where “distance” is the length of ... Read More »

TCP Connection Termination

Let’s suppose both client and server are in the Established state. Although the TCP connection termination can be initiated by either the client or the server, let’s assume here that the application process on the client side informs TCP that ... Read More »

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