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Questions tagged [tcp]

TCP stands for Transmission Control Protocol and is one of the core protocols of the Internet Protocol Suite. TCP complements the Internet Protocol (IP), and therefore the entire suite is commonly referred to as TCP/IP.

TCP is just one communications protocol on the web. Others include:

  • User Datagram Protocol (UDP)
  • Internet Control Message Protocol (ICMP)
  • Hypertext Transfer Protocol (HTTP)
  • Post Office Protocol (POP3)
  • File Transfer Protocol (FTP)
  • Internet Message Access Protocol (IMAP)

TCP on Wikipedia

906 questions
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Is an ACK necessary when using reliable protocols like TCP? How much overhead / throughput penalty does it create?

Is an ACK necessary when using reliable protocols like TCP? How much overhead / throughput penalty does it create?
user678521
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2 answers

What do these remote addresses, local addresses, and states in TCPview mean?

I have been using TCPview lately to see what connections are made by different processes on my PC. Would somebody please explain what the following situations mean? Thanks. TCP Local Address: PC1234567890:3883 Remote Address: PC1234567890:0 State:…
Joe
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1 answer

How does Ident work?

I am having a hard time understanding how the ident protocol works. I came across a summary of how it works at Wikipedia however don't quite follow what it means The Ident Protocol is designed to work as a server daemon, on a user's computer, where…
PeanutsMonkey
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How to prove provider is blocking incoming traffic on some ports?

I hope this is not too much focused on home networks, because that's where I hit the problem, but I think it may be of general interest nonetheless. I have a cable connection (Cisco EPC3208) and a NAS (Synology DS413). Basically, I have problems…
bers
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What means "Communication administratively filtered"

I am facing a problem in a foreign country reaching a special server per TCP/IP. ICMP is no problem but it looks like the dialup access provider is somehow filtering the TCP port 25 (SMTP). I get a connection refused when trying this port. However…
Thomas
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Sending large data over TCP and progress indicators

It is my understanding that when you open a tcp connection to send data the tcp layer on the receiving end holds on to all the packet until the transmission is complete, then sends all the data up to the application. From wikipedia on tcp: Due to…
Shane
  • 123
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Need Help Troubleshooting Network Issue (Client TCP Connections Stuck in FIN_WAIT_2)

(Note: I originally asked this question on the "Network Engineering" side, but a moderator there rejected it as "off topic" and told me to ask here instead.) I am running a video surveillance server called ZoneMinder (version 1.26.5) on a Fedora 18…
dvarapala
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tcpview cannot kill connection/process

I have a program that sometime misses to close a tcp connection. After the program has ended I can see that the port is taken. TCPViewer shows "non-existent" in the "Process" column. If i try to "End process" or "Close connection" nothing…
Stig
  • 21
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2 answers

Does TCP verify data all at once or as a packet by packet verification?

I know that TCP uses verification to ensure accuracy of data by sending to the server. My question is does it verify everything at once or as it comes in? Quick Example: Let's say I am loading the Superuser page here. For simplicity it can fit in 5…
Anonymous Penguin
  • 797
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Data corruption after upgrading broadband speed and modem/router

I'm using an ISP called Fibertel in Argentina, and I recently upgraded my connection to 30 down/3 up. With this change came a new modem+router: the Motorola SBG 6580. Before I had something like 1 down/300k up on a cable modem (don't recall brand)…
cdmckay
  • 119
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How will I know whether my laptop computer is being shared

How will I know whether my laptop computer is being shared through TCP and IP or not been shared? What command should I look or click through? When I click the button bar for Local Area Connection Properties, it only show the General Button. By the…
alvin
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TCP PUSH and segments

I am reading the TCP PUSH section in the TCP/IP Guide, and have a question on this paragraph: It's important to realize that the push function only forces immediate delivery of data. It does not change the fact that TCP provides no boundaries…
user26825
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TCP window probe

I was referred to this site when originally asking in the Networking SE. I have a few questions about rwnd advertisements in TCP. I have read the RFC but was left with unanswered thoughts (or maybe I have missed some things). Perhaps some of answers…
EL_9
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TCP on the same (server side) source port to multiple (different destinations)?

Question 2 Is it true that a TCP server may send segments with the same (server side) source port to multiple (different destinations)?
user532980
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Session layer in OSI vs TCP/IP

I'm sort of confused here: According to several illustrations I've seen and material from Cisco the session layer from OSI is part of the application layer in TCP/IP. This makes no sense to me since it is the TCP protocol of the transport layer (in…
Axel Kennedal
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