I am using Windows OS and when I ping 1.1.1.1 address, it displays an output that shows me how much time it takes to send an ICMP packet from my computer to the server and gets back an answer from the server to my computer. Before diving into retransmissions and examining the types of retransmissions, we need to explain two concepts.įor sake of simplicity, lets first go with pinging. Packet loss is mostly caused by hardware issues, software bugs, network congestion, and some other factors. Packet loss may happen due to two main reasons which can fall into many sub categories. After that, the copy gets deleted and resources are released for future use. Whenever a sender transmits a packet, it saves a copy of the packet int its buffer and it stays there until receiving side acknowledges that it has received the packet.

The lost packets are recovered by retransmissions and acknowledgments while sequence numbers are used to determine correct packet reordering in the receiving side. The protocol offers packet delivery guarantees, even if some of the packets have been lost during the transmission. TCP is one of the reliable protocols working in the transport layer, in terms of Open System Interconnect (OSI) model.

Wireshark retransmission analysis