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../../bibliography.rst:126
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McQuillan, J. M., Richer, I., and Rosen, E. C., `An overview of the new routing algorithm for the ARPANET <http://doi.acm.org/10.1145/800092.802981>`_. In Proceedings of the Sixth Symposium on Data Communications (Pacific Grove, California, United States, November 27 - 29, 1979). SIGCOMM '79. ACM, New York, NY, 63-68.
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../../glossary.rst:325
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Ethernet
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../../exercises/ex-sharing.rst:647
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the host continues to listen until the communication channel becomes free. It transmits as soon as the communication channel becomes free.
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../../exercises/reliability.rst:85
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Is it possible for a selective-repeat receiver to inter-operate with a go-back-n sender ? Justify your answer.
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../../exercises/network.rst:360
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Routes on B
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../../exercises/sockets.rst:326
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Endianness: exchanging integers between different computers
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../../principles/referencemodels.rst:146
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The OSI reference model
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../../principles/network.rst:143
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Computing forwarding tables
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../../principles/reliability.rst:180
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All the functions related to the physical transmission or information through a wire (or a wireless link) are usually known as the `physical layer`. The physical layer allows thus two or more entities that are directly attached to the same transmission medium to exchange bits. Being able to exchange bits is important as virtually any information can be encoded as a sequence of bits. Electrical engineers are used to processing streams of bits, but computer scientists usually prefer to deal with higher level concepts. A similar issue arises with file storage. Storage devices such as hard-disks also store streams of bits. There are hardware devices that process the bit stream produced by a hard-disk, but computer scientists have designed filesystems to allow applications to easily access such storage devices. These filesystems are typically divided into several layers as well. Hard-disks store sectors of 512 bytes or more. Unix filesystems group sectors in larger blocks that can contain data or `inodes` representing the structure of the filesystem. Finally, applications manipulate files and directories that are translated in blocks, sectors and eventually bits by the operating system.
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../../principles/transport.rst:86
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Besides character strings, some applications also need to exchange 16 bits and 32 bits fields such as integers. A naive solution would have been to send the 16- or 32-bits field as it is encoded in the host's memory. Unfortunately, there are different methods to store 16- or 32-bits fields in memory. Some CPUs store the most significant byte of a 16-bits field in the first address of the field while others store the least significant byte at this location. When networked applications running on different CPUs exchange 16 bits fields, there are two possibilities to transfer them over the transport service :
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../../principles/sharing.rst:179
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Discarding packets is one of the signals that the network nodes can use to inform the hosts of the current level of congestion. Buffers on network nodes are usually used as FIFO queues to preserve packet ordering. Several `packet discard mechanisms` have been proposed for network nodes. These techniques basically answer two different questions :
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../../principles/security.rst:398
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The Elliptic Curve Cryptography techniques [#fecc]_ that rely on special properties of elliptic curves.
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../../exercises/ipv6.rst:416
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on router ``R6``
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../../exercises/routing-protocols.rst:491
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The last step is to specify to which AS each router belongs and to configure the eBGP sessions and their routing policies. IPMininet_ abstracts most of the complexity of the configuration of these policies by supporting two policies
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../../exercises/tcp-2.rst:502
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We can now explore how TCP's retransmission techniques interact with the congestion control scheme. The Linux TCP code that combines these two techniques contains several heuristics to improve their performance. We start with a transfer of 8KBytes where the penultimate segment is not received by the remote host. In this case, TCP does not receive enough acknowledgments to trigger the fast retransmit and it must wait for the expiration of the retransmission timer. This script is available from :download:`/exercises/packetdrill_scripts/slow-start-rto2.pkt`.
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../../protocols/bgp.rst:127
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`KEEPALIVE` : this message is used to ensure a regular exchange of messages on the BGP session, even when no route changes. When a BGP router has not sent an `UPDATE` message during the last 30 seconds, it shall send a `KEEPALIVE` message to confirm to the other peer that it is still up. If a peer does not receive any BGP message during a period of 90 seconds [#fdefaultkeepalive]_, the BGP session is considered to be down and all the routes learned over this session are withdrawn.
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../../protocols/congestion.rst:205
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:math:`Throughput=\frac{area \times MSS}{time} = \frac{ \frac{3 \times W^2}{8}}{\frac{W}{2} \times rtt}` or, after having eliminated `W`, :math:`Throughput=\sqrt{\frac{3}{2}} \times \frac{MSS}{rtt \times \sqrt{p}}`
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../../protocols/email.rst:212
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`text`. The message part contains information in textual format. There are several subtypes : `text/plain` for regular ASCII text, `text/html` defined in :rfc:`2854` for documents in :term:`HTML` format or the `text/enriched` format defined in :rfc:`1896`. The `Content-Type:` header line may contain a second parameter that specifies the character set used to encode the text. `charset=us-ascii` is the standard ASCII character table. Other frequent character sets include `charset=UTF8` or `charset=iso-8859-1`. The `list of standard character sets <http://www.iana.org/assignments/character-sets>`_ is maintained by :term:`IANA`.
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../../protocols/ethernet.rst:177
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1000Base-CX
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../../protocols/http.rst:160
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the `Content-Encoding:` header indicates how the :term:`MIME document` has been encoded. For example, this header would be set to `x-gzip` for a document compressed using the gzip_ software.
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