cnp3-ebook/protocols/tcp — English @ Weblate

Exit Zen

10 ../../protocols/tcp.rst:26

	English To provide this service, TCP relies on a simple segment format that is shown in the figure below. Each TCP segment contains a header described below and, optionally, a payload. The default length of the TCP header is twenty bytes, but some TCP headers contain options. 268/10000 · 268
11 ../../protocols/tcp.rst:32

	English TCP header format 17/10000 · 17
12 ../../protocols/tcp.rst:35

	English A TCP header contains the following fields : 44/10000 · 44
13 ../../protocols/tcp.rst:37

	English the `source and destination ports`. The source and destination ports play an important role in TCP, as they allow the identification of the connection to which a TCP segment belongs. When a client opens a TCP connection, it typically selects an ephemeral TCP port number as its source port and contacts the server by using the server's port number. All the segments that are sent by the client on this connection have the same source and destination ports. The server sends segments that contain as source (resp. destination) port, the destination (resp. source) port of the segments sent by the client (see figure :ref:`fig-tcpports`). A TCP connection is always identified by four pieces of information : 706/10000 · 706
14 ../../protocols/tcp.rst:39

	English the address of the client 25/10000 · 25
15 ../../protocols/tcp.rst:40

	English the address of the server 25/10000 · 25
16 ../../protocols/tcp.rst:41

	English the port chosen by the client 29/10000 · 29
17 ../../protocols/tcp.rst:42

	English the port chosen by the server 29/10000 · 29
18 ../../protocols/tcp.rst:44

	English the `sequence number` (32 bits), `acknowledgment number` (32 bits) and `window` (16 bits) fields are used to provide a reliable data transfer, using a window-based protocol. In a TCP bytestream, each byte of the stream consumes one sequence number. Their usage is described in more detail in section :ref:`TCPReliable` 318/10000 · 318
19 ../../protocols/tcp.rst:45

	English the `Urgent pointer` is used to indicate that some data should be considered as urgent in a TCP bytestream. However, it is rarely used in practice and will not be described here. Additional details about the utilization of this pointer may be found in :rfc:`793`, :rfc:`1122` or [Stevens1994]_ 293/10000 · 293
20 ../../protocols/tcp.rst:46

	English the flags field contains a set of bit flags that indicate how a segment should be interpreted by the TCP entity receiving it : 126/10000 · 126
21 ../../protocols/tcp.rst:48

	English the `SYN` flag is used during connection establishment 54/10000 · 54
22 ../../protocols/tcp.rst:49

	English the `FIN` flag is used during connection release 48/10000 · 48
23 ../../protocols/tcp.rst:50

	English the `RST` is used in case of problems or when an invalid segment has been received 82/10000 · 82
24 ../../protocols/tcp.rst:51

	English when the `ACK` flag is set, it indicates that the `acknowledgment` field contains a valid number. Otherwise, the content of the `acknowledgment` field must be ignored by the receiver 182/10000 · 182
25 ../../protocols/tcp.rst:52

	English the `URG` flag is used together with the `Urgent pointer` 57/10000 · 57
26 ../../protocols/tcp.rst:53

	English the `PSH` flag is used as a notification from the sender to indicate to the receiver that it should pass all the data it has received to the receiving process. However, in practice TCP implementations do not allow TCP users to indicate when the `PSH` flag should be set. 270/10000 · 270
27 ../../protocols/tcp.rst:55

	English the `checksum` field contains the value of the Internet checksum computed over the entire TCP segment and a pseudo-header as with UDP 133/10000 · 133
28 ../../protocols/tcp.rst:56

	English the `Reserved` field was initially reserved for future utilization. It is now used by :rfc:`3168`. 98/10000 · 98
29 ../../protocols/tcp.rst:57

	English the `TCP Header Length` (THL) or `Data Offset` field is a four bits field that indicates the size of the TCP header in 32 bit words. The maximum size of the TCP header is thus 64 bytes. 185/10000 · 185

Shortcut	Action
`?`	Open available keyboard shortcuts.
`Alt` + `Home`	Navigate to the first translation in the current search.
`Alt` + `End`	Navigate to the last translation in the current search.
`Alt` + `PageUp` or `Ctrl` + `↑` or `Alt` + `↑` or `Cmd` + `↑` or	Navigate to the previous translation in the current search.
`Alt` + `PageDown` or `Ctrl` + `↓` or `Alt` + `↓` or `Cmd` + `↓` or	Navigate to the next translation in the current search.
`Ctrl` + `Enter` or `Cmd` + `Enter`	Submit current form; this works the same as pressing Save and continue while editing translation.
`Ctrl` + `Shift` + `Enter` or `Cmd` + `Shift` +`Enter`	Unmark translation as Needing edit and submit it.
`Alt` + `Enter` or `Option` + `Enter`	Submit the string as a suggestion; this works the same as pressing Suggest while editing translation.
`Ctrl` + `E` or `Cmd` + `E`	Focus on translation editor.
`Ctrl` + `U` or `Cmd` + `U`	Focus on comment editor.
`Ctrl` + `M` or `Cmd` + `M`	Shows Automatic suggestions tab.
`Ctrl` + `1` to `Ctrl` + `9` or `Cmd` + `1` to `Cmd` + `9`	Copies placeable of a given number from source string.
`Ctrl` + `M` followed by `1` to `9` or `Cmd` + `M` followed by `1` to `9`	Copy the machine translation of a given number to current translation.
`Ctrl` + `I` followed by `1` to `9` or `Cmd` + `I` followed by `1` to `9`	Ignore one item in the list of failing checks.
`Ctrl` + `J` or `Cmd` + `J`	Shows the Nearby strings tab.
`Ctrl` + `S` or `Cmd` + `S`	Focus on search field.
`Ctrl` + `O` or `Cmd` + `O`	Copy the source string.
`Ctrl` + `Y` or `Cmd` + `Y`	Toggle the Needs editing checkbox.
`→`	Browse the next translation string.
`←`	Browse the previous translation string.