2. cnp3-ebook
3. English
4. Zen

42 ../../principles/sharing.rst:242
	English ↹ ↵ NBS … “ ” ‘ ’ ﹙-﹚ ‐ – — Discarding packets is a frequent reaction to network congestion. Unfortunately, discarding packets is not optimal since a packet which is discarded on a network node has already consumed resources on the upstream nodes. There are other ways for the network to inform the end hosts of the current congestion level. A first solution is to mark the packets when a node is congested. Several networking technologies have relied on this kind of packet marking. 455/10000 · 455
42 ../../principles/transport.rst:106
	English ↹ ↵ NBS … “ ” ‘ ’ ﹙-﹚ ‐ – — The first possibility was named `big-endian` in a note written by Cohen [Cohen1980]_ while the second was named `little-endian`. Vendors of CPUs that used `big-endian` in memory insisted on using `big-endian` encoding in networked applications while vendors of CPUs that used `little-endian` recommended the opposite. Several studies were written on the relative merits of each type of encoding, but the discussion became almost a religious issue [Cohen1980]_. Eventually, the Internet chose the `big-endian` encoding, i.e. multi-byte fields are always transmitted by sending the most significant byte first, :rfc:`791` refers to this encoding as the :term:`network-byte order`. Most libraries [#fhtonl]_ used to write networked applications contain functions to convert multi-byte fields from memory to the network byte order and the reverse. 844/10000 · 844
42 ../../principles/security.rst:412
	English ↹ ↵ NBS … “ ” ‘ ’ ﹙-﹚ ‐ – — In practice, encrypting a message to sign it can be computationally costly, in particular if the message is a large file. A faster solution would be to summarize the document and only sign the summary of the document. A naive approach could be based on a checksum or CRC computed over the message. Alice would then compute :math:`C=Checksum(M)` and :math:`SC=E_p(A_{priv},C)`. She would then send both `M` and `SC` to the recipient of the message who can easily compute `C` from `SC` and verify the authenticity of the message. Unfortunately, this solution does not protect Alice and the message's recipient against a man-in-the-middle attack. If Mallory can intercept the message sent by Alice, he can easily modify Alice's message and tweak it so that it has the same checksum as the original one. The CRCs, although more complex to compute, suffer from the same problem. 873/10000 · 873
42 ../../exercises/ipv6.rst:436
	English ↹ ↵ NBS … “ ” ‘ ’ ﹙-﹚ ‐ – — Sometimes, static routes must be configured on networks to enforce certain paths. Consider the six routers network shown in the figure below. 141/10000 · 141
42 ../../exercises/routing-protocols.rst:512
	English ↹ ↵ NBS … “ ” ‘ ’ ﹙-﹚ ‐ – — We can now run this simple network. 35/10000 · 35
42 ../../exercises/tcp-2.rst:593
	English ↹ ↵ NBS … “ ” ‘ ’ ﹙-﹚ ‐ – — Our last scenario is when the first segment sent is lost. In this case, two round-trip-times are required to retransmit the missing segment and recover from the loss. This script is available from :download:`/exercises/packetdrill_scripts/slow-start-frr3.pkt`. 260/10000 · 260
42 ../../protocols/bgp.rst:131
	English ↹ ↵ NBS … “ ” ‘ ’ ﹙-﹚ ‐ – — a list of IP prefixes that are withdrawn 40/10000 · 40
42 ../../protocols/congestion.rst:211
	English ↹ ↵ NBS … “ ” ‘ ’ ﹙-﹚ ‐ – — TCP connections with a small round-trip-time can achieve a higher throughput than TCP connections having a longer round-trip-time when losses occur. This implies that the TCP congestion control scheme is not completely fair since it favors the connections that have the shorter round-trip-times. 295/10000 · 295
42 ../../protocols/email.rst:214
	English ↹ ↵ NBS … “ ” ‘ ’ ﹙-﹚ ‐ – — `audio`. The message part contains an audio clip. The subtype indicates the format of the audio clip like `wav <http://en.wikipedia.org/wiki/Wav>`_ or `mp3 <http://en.wikipedia.org/wiki/Mp3>`_. 193/10000 · 193
42 ../../protocols/ethernet.rst:178
	English ↹ ↵ NBS … “ ” ‘ ’ ﹙-﹚ ‐ – — 1000Base-SX 11/10000 · 11
42 ../../protocols/http.rst:164
	English ↹ ↵ NBS … “ ” ‘ ’ ﹙-﹚ ‐ – — the `Server:` header indicates the version of the web server that has generated the HTTP response. Some servers provide information about their software release and optional modules that they use. For security reasons, some system administrators disable these headers to avoid revealing too much information about their server to potential attackers. 350/10000 · 350
42 ../../protocols/ipv6.rst:156
	English ↹ ↵ NBS … “ ” ‘ ’ ﹙-﹚ ‐ – — A `subnet identifier` that identifies a customer of the ISP 59/10000 · 59
42 ../../protocols/ethernet.rst:169
	English ↹ ↵ NBS … “ ” ‘ ’ ﹙-﹚ ‐ – — Comments 8/10000 · 8
42 ../../protocols/routing.rst:139
	English ↹ ↵ NBS … “ ” ‘ ’ ﹙-﹚ ‐ – — How to quickly detect a link failure ? 38/10000 · 38
42 ../../protocols/tcp.rst:129
	English ↹ ↵ NBS … “ ” ‘ ’ ﹙-﹚ ‐ – — At this point, the TCP connection is open and both the client and the server are allowed to send TCP segments containing data. This is illustrated in the figure below. 167/10000 · 167
42 ../../protocols/tls.rst:190
	English ↹ ↵ NBS … “ ” ‘ ’ ﹙-﹚ ‐ – — The server replies to the ``ClientHello`` with several messages: 64/10000 · 64
42 ../../protocols/wifi.rst:107
	English ↹ ↵ NBS … “ ” ‘ ’ ﹙-﹚ ‐ – — When a frame is sent from a WiFi device to a server attached to the same LAN as the access point, the first address of the frame is set to the MAC address of the access point, the second address is set to the MAC address of the source WiFi device and the third address is the address of the final destination on the LAN. When the server replies, it sends an Ethernet frame whose source address is its MAC address and the destination address is the MAC address of the WiFi device. This frame is captured by the access point that converts the Ethernet header into an 802.11 frame header. The 802.11 frame sent by the access point contains three addresses : the first address is the MAC address of the destination WiFi device, the second address is the MAC address of the access point and the third address the MAC address of the server that sent the frame. 854/10000 · 854
42 ../../bibliography.rst:59
	English ↹ ↵ NBS … “ ” ‘ ’ ﹙-﹚ ‐ – — Dalal, Y. K. and Printis, R. S., `48-bit absolute internet and Ethernet host numbers <http://doi.acm.org/10.1145/800081.802680>`_. In Proceedings of the Seventh Symposium on Data Communications (Mexico City, Mexico, October 27 - 29, 1981). SIGCOMM '81. ACM, New York, NY, 240-245. 280/10000 · 280
42 ../../principles/reliability.rst:201
	English ↹ ↵ NBS … “ ” ‘ ’ ﹙-﹚ ‐ – — Computer scientists are usually not interested in exchanging bits between two hosts. They prefer to write software that deals with larger blocks of data in order to transmit messages or complete files. Thanks to the physical layer service, it is possible to send a continuous stream of bits between two hosts. This stream of bits can include logical blocks of data, but we need to be able to extract each block of data from the bit stream despite the imperfections of the physical layer. In many networks, the basic unit of information exchanged between two directly connected hosts is often called a `frame`. A `frame` can be defined as a sequence of bits that has a particular syntax or structure. We will see examples of such frames later in this chapter. 758/10000 · 758
43 ../../exercises/sockets.rst:332
	English ↹ ↵ NBS … “ ” ‘ ’ ﹙-﹚ ‐ – — send the most significant byte followed by the least significant byte 69/10000 · 69