Exit Zen
49
../../bibliography.rst:314
English
Russell A., `Rough Consensus and Running Code and the Internet-OSI Standards War <https://dx.doi.org/10.1109/MAHC.2006.42>`_, IEEE Annals of the History of Computing, July-September 2006
0/1860 · 186
49
../../glossary.rst:104
English
The File Transfer Protocol defined in :rfc:`959` has been the `de facto` protocol to exchange files over the Internet before the widespread adoption of HTTP :rfc:`2616`.
0/1690 · 169
49
../../exercises/network.rst:363
English
4 via D
0/100 · 7
49
../../exercises/sockets.rst:348
English
Here are some exercises that will help you to learn how to use sockets.
0/710 · 71
49
../../principles/reliability.rst:208
English
Bit rate and bandwidth
0/220 · 22
49
../../principles/sharing.rst:197
English
In virtual circuit networks, packet marking can be improved if the return packets follow the reverse path of the forward packets. It this case, a network node can detect congestion on the forward path (e.g. due to the size of its buffer), but mark the packets on the return path. Marking the return packets (e.g. the acknowledgments used by reliable protocols) provides a faster feedback to the sending hosts compared to FECN. This technique is usually called `Backward Explicit Congestion Notification (BECN)`.
0/5110 · 511
50
../../bibliography.rst:317
English
Sechrest, S., `An Introductory 4.4BSD Interprocess Communication Tutorial <http://docs.freebsd.org/44doc/psd/20.ipctut/paper.pdf>`_, 4.4BSD Programmer's Supplementary Documentation
0/1800 · 180
50
../../glossary.rst:198
English
FTP
0/100 · 3
50
../../exercises/network.rst:364
English
B
0/100 · 1
50
../../exercises/sockets.rst:364
English
Footnotes
0/100 · 9
50
../../principles/network.rst:216
English
the `data packets`
0/180 · 18
50
../../principles/reliability.rst:210
English
Bit rate and bandwidth are often used to characterize the transmission capacity of the physical service. The original definition of `bandwidth <https://www.merriam-webster.com/dictionary/bandwidth>`_, as listed in the `Webster dictionary <https://www.merriam-webster.com/dictionary>`_ is `a range of radio frequencies which is occupied by a modulated carrier wave, which is assigned to a service, or over which a device can operate`. This definition corresponds to the characteristics of a given transmission medium or receiver. For example, the human ear is able to decode sounds in roughly the 0-20 KHz frequency range. By extension, bandwidth is also used to represent the capacity of a communication system in bits per second. For example, a Gigabit Ethernet link is theoretically capable of transporting one billion bits per second.
0/8370 · 837
50
../../principles/transport.rst:115
English
The network layer ensures the delivery of packets on a hop-by-hop basis through intermediate nodes. As such, it provides a service to the upper layer. In practice, this layer is usually the `transport layer` that improves the service provided by the `network layer` to make it usable by applications.
0/3000 · 300
51
../../bibliography.rst:318
English
Scheifler, R., Gettys, J., `X Window System: The Complete Reference to Xlib <http://h30097.www3.hp.com/docs/base_doc/DOCUMENTATION/V51B_ACRO_SUP/XWINSYS.PDF>`_, X Protocol, ICCCM, XLFD, X Version 11, Release 4, Digital Press
0/2240 · 224
51
../../glossary.rst:200
English
The File Transfer Protocol is defined in :rfc:`959`
0/510 · 51
51
../../exercises/network.rst:364
English
1 via B
0/100 · 7
51
../../exercises/sockets.rst:365
English
For example, the ``htonl(3)`` (resp. ``ntohl(3)``) function the standard C library converts a 32-bits unsigned integer from the byte order used by the CPU to the network byte order (resp. from the network byte order to the CPU byte order). Similar functions exist in other programming languages.
0/2950 · 295
51
../../principles/network.rst:217
English
the `control packets`
0/210 · 21
51
../../principles/reliability.rst:215
English
Given that multi-symbol encodings cannot be used by all physical layers, a generic solution which can be used with any physical layer that is able to transmit and receive only bits `0` and `1` is required. This generic solution is called `stuffing` and two variants exist : `bit stuffing` and `character stuffing`. To enable a receiver to easily delineate the frame boundaries, these two techniques reserve special bit strings as frame boundary markers and encode the frames so that these special bit strings do not appear inside the frames.
0/5410 · 541
51
../../principles/sharing.rst:203
English
Dropping and marking packets is not the only possible reaction of a router that becomes congested. A router could also selectively delay packets belonging to some flows. There are different algorithms that can be used by a router to delay packets. If the objective of the router is to fairly distribute to bandwidth of an output link among competing flows, one possibility is to organize the buffers of the router as a set of queues. For simplicity, let us assume that the router is capable of supporting a fixed number of concurrent flows, say `N`. One of the queues of the router is associated to each flow and when a packet arrives, it is placed at the tail of the corresponding queue. All the queues are controlled by a `scheduler`. A `scheduler` is an algorithm that is run each time there is an opportunity to transmit a packet on the outgoing link. Various schedulers have been proposed in the scientific literature and some are used in real routers.
0/9570 · 957