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1

what happens if segment 50 gets missing along the line? The receiver can either simply wait for retransmission (when the sender's timer for a unACKed segment expires it is resent automatically) send duplicate ACKs (DUPACK) for 50 (the next expected segment) to prompt a faster retransmission The receiver can also selectively ACK (SACK) 51-100 to avoid a ...


0

Even if this is an old post, I'd like to give an answer as an detailled answer was not yet priveded and it is still the first Google result. Correct me if I'm wrong, I'm still learning too. The expression word is kind of confusing. Data Offset means the WHOLE Header content. The Offset, after which the Data starts. As the Header maximum size can be up to 60 ...


0

I know this is an old thread but there now is a solution for the video over ip world in "ST 2022-7:2019 - SMPTE Standard - Seamless Protection Switching of RTP Datagrams," in ST 2022-7:2019 , vol., no., pp.1-11, 13 May 2019, doi: 10.5594/SMPTE.ST2022-7.2019. https://ieeexplore.ieee.org/document/8716822 It basically sends two copies of every packet ...


5

IP fragmentation can cause excessive retransmission at the TCP level. TCP transmits information as a series of segments, and these are the units of acknowledgement and retransmission as well. If a TCP segment is lost in the network, the entire segment has to be retransmitted. If IP fragmentation occurs, the segment will be split into multiple fragments. The ...


0

TCP only acts on the packets it receives, it doesn't know which packets are on the line. If both sides sends data at the same time, from TCP's perspective, it will send data, then receive data, and after that it receives a packet containing an ACK Example from the perspective of side A: A -> B: SEQ=1000 SYN=1000 (SYN is a random value in practice) ...


2

Rather simple: each direction has its own and independent sequence number and sliding window. So, whether the ends are sending data unidirectionally (one end just ACKing with otherwise empty segments) or bidirectionally doesn't matter.


8

IP packet level fragmentation occurs when the transmitting side is not properly aware of the MTU of the path. This results in worse performance than if the packets are sized correctly already at the endpoint. For example, if the transmitting side of a TCP connection believes the path MTU to be 1500 bytes, it will send packets of that size. If the real path ...


28

Fragmentation is resource intensive in a router, and it slows packet forwarding. Today, we use PMTUD to determine the smallest MTU in the path so that packets are properly sized prior to sending. There are also fragmentation attacks, so many businesses drop fragments. What you are confusing is something like TCP segmentation, which is very different than ...


1

Yes. An increase in path cost only means that the path may be less preferred than another (or it may be the only path). If the route is still in the routing table, the router will still forward the packet.


1

can we still transfer packets between the two routers? Yes. But your network might not work efficiently or at all. Basically, most routing algorithms in practice use Dijkstra's algorithm (OSPF, IS-IS, SPB) which is faster to converge. Any router can only use the information that is has gained access to - effectively, until the network has converged, there's ...


-1

TCP Headers occur when a connection between client and server is established before data can be sent. The server must be listening (passive open) for connection requests from clients before a connection is established. Three-way handshake (active open), retransmission, and error-detection adds to reliability but lengthens latency. Applications that do not ...


1

That depends on whose definition of socket you use and in some cases whether the packet is opening a new connection or transferring data for an existing connction. The RFC that defines TCP defines the term socket as a combination of an IP address and a port. By this definition the two packets have the same socket on the server side but different sockets on ...


2

One option is to use an intermediary rendezvous server in the cloud, and all devices connect to it. There are several options for encryption, but we’d need more details before recommending something.


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