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../../principles/naming.rst:139
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Footnotes
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../../principles/network.rst:118
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Any solution which is used to compute the forwarding tables of a network must ensure that all destinations are reachable from any source. This implies that it must guarantee the absence of black holes and forwarding loops.
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../../principles/referencemodels.rst:125
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Reference models
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../../principles/reliability.rst:106
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With the above transmission scheme, a bit is transmitted by setting the voltage on the electrical cable to a specific value during some period of time. We have seen that due to electromagnetic interference, the voltage measured by the receiver can differ from the voltage set by the transmitter. This is the main cause of transmission errors. However, this is not the only type of problem that can occur. Besides defining the voltages for bits `0` and `1`, the above transmission scheme also specifies the duration of each bit. If one million bits are sent every second, then each bit lasts 1 microsecond. On each host, the transmission (resp. the reception) of each bit is triggered by a local clock having a 1 MHz frequency. These clocks are the second source of problems when transmitting bits over a wire. Although the two clocks have the same specification, they run on different hosts, possibly at a different temperature and with a different source of energy. In practice, it is possible that the two clocks do not operate at exactly the same frequency. Assume that the clock of the transmitting host operates at exactly 1000000 Hz while the receiving clock operates at 999999 Hz. This is a very small difference between the two clocks. However, when using the clock to transmit bits, this difference is important. With its 1000000 Hz clock, the transmitting host will generate one million bits during a period of one second. During the same period, the receiving host will sense the wire 999999 times and thus will receive one bit less than the bits originally transmitted. This small difference in clock frequencies implies that bits can "disappear" during their transmission on an electrical cable. This is illustrated in the figure below.
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../../principles/sharing.rst:150
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the node's capacity measured in bits per second
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../../principles/transport.rst:66
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`space` : `0100000b`
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../../bibliography.rst:103
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Karn, P., Price, H., Diersing, R., `Packet radio in amateur service <https://dx.doi.org/10.1109/JSAC.1985.1146214>`_, IEEE Journal on Selected Areas in Communications, 3, May, 1985
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../../exercises/ex-sharing.rst:610
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If host `A` uses a window of two segments and needs to transmit five segments of data. How long does the entire transfer lasts ?
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../../exercises/network.rst:323
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Would this network work correctly with port-forwarding tables if :
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../../exercises/reliability.rst:67
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Implement a small software that computes the CRC-32 for a text file. Then, modify the contents of the file to change an even number of bits or an odd number of bits inside the file. When modifying the file, remember that an ASCII file is composed of 8 bits characters that are encoded by using the ASCII table that you can find at : http://en.wikipedia.org/wiki/ASCII . You can also write a small program that produces binary files that are a small variation of each other.
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../../exercises/sockets.rst:283
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The ``::1`` IPv6 address identifies the computer on which the current program is running.
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../../principles/naming.rst:140
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The :term:`hosts.txt` file is not maintained anymore. A historical snapshot from April 1984 is available from http://ftp.univie.ac.at/netinfo/netinfo/hosts.txt
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../../principles/network.rst:122
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The `forwarding tables` and the precise format of the packets that are exchanged inside the network are part of the `data plane` of the network. This `data plane` contains all the protocols and algorithms that are used by hosts and routers to create and process the packets that contain user data. On high-end routers, the data plane is often implemented in hardware for performance reasons.
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../../principles/referencemodels.rst:128
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Two reference models have been successful in the networking community : the OSI reference model and the TCP/IP reference model. We discuss them briefly in this section.
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../../principles/reliability.rst:128
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A similar reasoning applies when the clock of the sending host is slower than the clock of the receiving host. In this case, the receiver will sense more bits than the bits that have been transmitted by the sender. This is illustrated in the figure below where the second bit received on the right was not transmitted by the left host.
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../../principles/sharing.rst:151
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the node's lookup performance measured in packets per second
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../../principles/transport.rst:68
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In addition, the :term:`ASCII` table also defines several non-printable or control characters. These characters were designed to allow an application to control a printer or a terminal. These control characters include `CR` and `LF`, that are used to terminate a line, and the `Bell` character which causes the terminal to emit a sound.
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../../bibliography.rst:106
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Kung, N.T. Morris, R., `Credit-based flow control for ATM networks <https://dx.doi.org/10.1109/65.372658>`_, IEEE Network, Mar/Apr 1995, Volume: 9, Issue: 2, pages: 40-48
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../../exercises/ex-sharing.rst:611
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Same question as above, but now host `A` uses the simple DECBIT congestion control mechanism and a maximum window size of four segments.
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../../exercises/network.rst:325
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Host `A` uses the same flat address for both links.
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