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../../protocols/congestion.rst:224
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`TCP Vegas`, which uses changes in the round-trip-time to estimate congestion in order to avoid it [BOP1994]_. This is one of the examples of the delay-based congestion control algorithms. A Vegas sender continuously measures the evolution of the round-trip-time and slows down when the round-trip-time increases significantly. This enables Vegas to prevent congestion when used alone. Unfortunately, if Vegas senders compete with more aggressive TCP congestion control schemes that only react to losses, Vegas senders may have difficulties to user their fair share of the available bandwidth.
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../../protocols/email.rst:230 • ../../protocols/email.rst:230 • ../../protocols/email.rst:230 • ../../protocols/email.rst:230
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Value
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../../protocols/ethernet.rst:193
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Additional information about the history of the Ethernet technology may be found at http://ethernethistory.typepad.com/
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../../protocols/http.rst:173
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the `Host:` header contains the fully qualified domain name of the URI being requested.
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../../protocols/ipv6.rst:168
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In today's deployments, interface identifiers are always 64 bits wide. This implies that while there are :math:`2^{128}` different IPv6 addresses, they must be grouped in :math:`2^{64}` subnets. This could appear as a waste of resources, however using 64 bits for the host identifier allows IPv6 addresses to be auto-configured and also provides some benefits from a security point of view, as explained in section ICMPv6_.
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../../protocols/ethernet.rst:174
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10Base-F
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../../protocols/routing.rst:152
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A second approach is to install all equal cost paths [#fmaxpaths]_ in the forwarding table and load-balance the packets on the different paths. Consider the case where a router has `N` different outgoing interfaces to reach destination `d`. A first possibility to load-balance the traffic among these interfaces is to use `round-robin`. `Round-robin` allows equally balancing the packets among the `N` outgoing interfaces. This equal load-balancing is important in practice because it allows better spreading the load throughout the network. However, few networks use this `round-robin` strategy to load-balance traffic on routers. The main drawback of `round-robin` is that packets that belong to the same flow (e.g. TCP connection) may be forwarded over different paths. If packets belonging to the same TCP connection are sent over different paths, they will probably experience different delays and arrive out-of-sequence at their destination. When a TCP receiver detects out-of-order segments, it sends duplicate acknowledgments that may cause the sender to initiate a fast retransmission and enter congestion avoidance. Thus, out-of-order segments may lead to lower TCP performance. This is annoying for a load-balancing technique whose objective is to improve the network performance by spreading the load.
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../../protocols/tcp.rst:157
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TCP connection establishment rejected by peer
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../../protocols/tls.rst:236
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``DHE_RSA``. This key exchange algorithm is the Ephemeral Diffie Hellman key exchange with RSA signatures to authenticate the key exchange. It operates as a classical authenticated Diffie Hellman key exchange. If this key exchange has been selected by the server, it sends its Diffie Hellman parameters in the ``ServerKeyExchange`` message and signs them with its private key. The client then continues the key exchange and sends the results of its own computation in the ``ClientKeyExchange`` message. ``DHE_RSA`` is thus an authenticated Diffie Hellman key exchange where the initial message is sent by the server (instead of the client as in our first example but since the protocol is symmetric, this does not matter).
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../../protocols/wifi.rst:135
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In addition to the data and control frames that we have briefly described above, 802.11 networks use several types of management frames. These management frames are used for various purposes. We briefly describe some of these frames below. A detailed discussion may be found in [IEEE802.11]_ and [Gast2002]_.
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../../bibliography.rst:317
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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
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../../glossary.rst:198
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FTP
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../../principles/network.rst:216
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the `data packets`
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../../principles/reliability.rst:210
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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.
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../../principles/transport.rst:115
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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.
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../../principles/security.rst:478
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A naive approach would be to rely on hash functions. Since hash functions are non-invertible, Alice and Bob could decide to use them to exchange Alice's password in a secure manner. Then, Alice could be authenticated by using the following exchange.
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../../exercises/ipv6.rst:481
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The packets whose destinations are ``A1``, ``A2``, ``B1`` or ``B2`` are never forwarded via router ``R4``
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../../exercises/routing-protocols.rst:598
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Besides :manpage:`ping6(8)` and :manpage:`traceroute6(8)`, it is also useful to interact with the BGP daemon that runs on each of our routers. This is done by connecting on the Command Line Interface of the BGP router using telnet.
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../../exercises/tcp-2.rst:646
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the value of the duplicate acknowledgment threshold is fixed and set to 3
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../../protocols/bgp.rst:159
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In this figure, the router receives BGP messages on the left part of the figure, processes these messages and possibly sends BGP messages on the right part of the figure. A BGP router contains three important data structures :
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