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Questions tagged [retransmit-timeout]

Retransmission, essentially identical with Automatic repeat request (ARQ), is the resending of packets which have been either damaged or lost.

Retransmission, essentially identical with Automatic repeat request (ARQ), is the resending of packets which have been either damaged or lost.

It is a term that refers to one of the basic mechanisms used by protocols operating over a packet switched computer network to provide reliable communication (such as that provided by a reliable byte stream, for example TCP).

Such networks are usually 'unreliable', meaning they offer no guarantees that they will not delay, damage, or lose packets, or deliver them out of order. Protocols which provide reliable communication over such networks use a combination of acknowledgments (i.e. an explicit receipt from the destination of the data), retransmission of missing and/or damaged packets (usually initiated by a time-out), and checksums to provide that reliability.

Wikipedia: http://en.wikipedia.org/wiki/Retransmission_%28data_networks%29

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When is a TCP connection considered idle?

I have a requirement to enable TCP keepalive on any connections and now I am struggling with the results from our test case. I think this is because I do not really understand when the first keepalive probe is sent. I read the following in the…
Jens
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How does Windows decide which setting/template (Internet vs Datacenter) is applied to TCP connections?

In order to globally configure Minimum RTO; Delayed Ack Timeout; Congestion algo etc. under Windows 7 and above one is supposed to use network TCP templates. To see those you can use Get-NetTCPSetting powershell cmdlet: PS C:\Users\Administrator>…
Jan
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How to Find TCP Retransmissions while sniffing packets in C

I've written a simple source file that can read pcap files using the libpcap library in C. I can parse the packets one by one and analyze them up to a point. I want to be able to deduce whether a TCP packet I parsed is a TCP retransmission or not.…
Konstantinos Zafeiris
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Cannot see retransmission packet from client to server

I have a custom client-server application both running on LAN(OS-Windows8). I used keep-alive option in the client and I see Keep alive packets in Wireshark. However, when I unplug the network cable of the machine the server is running on, I do not…
user2970559
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TCP Retransmission: how many packets will be re-sent?

How does the TCP Retransmission? Which formula is determined by how many packets will be re-sent? I understand it is set somewhere in the cubic tcp, but where? Interested in how it works in Linux. I use Debian 8 and just looking dumps. I set up a…
Alex Panchenko
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Wireshark showing retransmissions and DUP ACKs even though client receives full data file

I am using Wireshark to analyze TCP packets (originally USB packets from total phase that get converted into pcapng for wireshark). There is currently a script that converts the total phase .csv export into a pcapng that is opened with Wireshark.…
lsahdow
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will server retransmit an ACK packet?

A tcp connection has a client and a server, my question is will the server start a timer when it sends an ACK packet to the client? and will the server retransmit that ACK packet if the packet gets timeout or lost?
luke zou
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How to reduce delays caused by a Server TCP Spurious retransmission and subsequent Client TCP retransmission?

I have a Dotnet application (running on a Windows PC) which communicates with a Linux box via OPC UA. The use case here is to make ~40 read requests to the server in serial. Once these 40 read calls are complete, the next cycle of 40 read calls…
NeuralLynx
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Winsock - Retransmission Seq incremented

I get the following when communicating with a custom client. With custom client i mean a housemade PCB with a FPGA which runs the Triple-Speed Ethernet Intel FPGA IP. It does not make a difference if a switch is between the PC and the PCB. Workflow…
Eggi
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MySQL stuck or network issue?

we have mysql-server(5.5.47)that hosted on physical server. It listen external internet interface(with restrict user access), mysql server intensively used from different places(we use different libraries to communicate with mysql). But sometimes…
user2746626
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TCP retranmission timer overrides/kills TCP keepalive timer, delaying disconnect discovery

Machine - linux, 3.10.19 kernel This is in a large distributed system, there are several servers and clients (on same as well as different nodes/machines) having TCP connections with each other. Test case: The client program node/machine is switched…
brokenfoot
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VB.net multithreading to fix a device driver

I have tried to code a VB.net based device driver for receiving data in an ASTM protocol. The driver has to further process the data and send it to a database -based software ("biologic"). Indeed, I succeeded in accomplishing both tasks when a small…
user3229164
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Setting default RTO (Retransmit Timeout) value in ns-3 simulator

I found this in rtt-estimator.h the constructor sets the value for m_initialEstimatedRtt which I believe directly controls the Retransmit Timeout value. I am not sure how to set the value for m_initialEstimatedRtt. I see a method named…
AturSams
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Do DLLs have a lower priority that may affect ethernet functionality? Experiencing TCP retransmissions

I have some modbus ethernet tcp communications that I'm attempting to do in a DLL. I get numerous TCP Retransmissions from the target device, as seen in WireShark. (In this image, 192.168.1.5 is the Modbus device. 192.168.1.72 is the…
Mike Gibson
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