2. cnp3-ebook
3. English
4. Zen

36 ../../protocols/rpc.rst:122
	English ↹ ↵ NBS … “ ” ‘ ’ ﹙-﹚ ‐ – — `data`: an optional field that provides additional information about the error. 79/10000 · 79
36 ../../protocols/ssh.rst:269
	English ↹ ↵ NBS … “ ” ‘ ’ ﹙-﹚ ‐ – — Among the various features of the ``ssh`` protocol, it is interesting to mention how users are authenticated by the server. The ``ssh`` protocol supports the classical username/password authentication (but both the username and the password are transmitted over the secure encrypted channel). In addition, ``ssh`` supports two authentication mechanisms that rely on public keys. To use the first one, each user needs to generate his/her own public/private key pair and store the public key on the server. To be authenticated, the user needs to sign a message containing his/her public key by using his/her private key. The server can easily verify the validity of the signature since it already knows the user's public key. The second authentication scheme is designed for hosts that trust each other. Each host has a public/private key pair and stores the public keys of the other hosts that it trusts. This is typically used in environments such as university labs where each user could access any of the available computers. If Alice has logged on ``computer1`` and wants to execute a command on ``computer2``, she can create an ``ssh`` session on this computer and type (again) her password. With the host-based authentication scheme, ``computer1`` signs a message with its private key to confirm that it has already authenticated Alice. ``computer2`` would then accept Alice's session without asking her credentials. 1421/10000 · 1421
36 ../../protocols/tcp.rst:116
	English ↹ ↵ NBS … “ ” ‘ ’ ﹙-﹚ ‐ – — Upon reception of this segment (which is often called a `SYN segment`), the server host replies with a segment containing : 123/10000 · 123
36 ../../protocols/tls.rst:150
	English ↹ ↵ NBS … “ ” ‘ ’ ﹙-﹚ ‐ – — `Random number`: security protocols rely on random numbers. The client sends a 32 bytes long random number where usually four of these bytes correspond to the client's clock. This random number is used, together with the server's random number, as a seed to generate the security keys. 285/10000 · 285
36 ../../protocols/wifi.rst:54
	English ↹ ↵ NBS … “ ” ‘ ’ ﹙-﹚ ‐ – — An 802.11 infrastructure network 32/10000 · 32
36 ../../principles/security.rst:378
	English ↹ ↵ NBS … “ ” ‘ ’ ﹙-﹚ ‐ – — a decryption function, :math:`D_{p}`, that takes a key and a message as parameters 82/10000 · 82
36 ../../protocols/http2.rst:239
	English ↹ ↵ NBS … “ ” ‘ ’ ﹙-﹚ ‐ – — HTTP/2.0 is a new version of the HTTP protocol that still uses port 80. When a client contacts an HTTP server, it must be able to determine whether it supports HTTP/1.x or HTTP/2.0. If the client sends a binary encoded HTTP/2.0 request to a server that only supports the ASCII encoded HTTP/1.x, it could cause problems on the server and even crash it. To minimize the risk of crashing HTTP/1.x servers, an HTTP/2.0 session starts like an HTTP/1.1 session and the first request contains the `Connection`, `Upgrade` and `HTTP2-Settings` headers. An example of such a request to upgrade the version of HTTP is shown below. 619/10000 · 619
36 ../../principles/sharing.rst:232
	English ↹ ↵ NBS … “ ” ‘ ’ ﹙-﹚ ‐ – — `What triggers a packet to be discarded ?` What are the conditions that lead a network node to decide to discard a packet? The simplest answer to this question is : `When the buffer is full`. Although this is a good congestion indication, it is probably not the best one from a performance viewpoint. An alternative is to discard packets when the buffer occupancy grows too much. In this case, it is likely that the buffer will become full shortly. Since packet discarding is an information that allows hosts to adapt their transmission rate, discarding packets early could allow hosts to react earlier and thus prevent congestion from happening. 646/10000 · 646
37 ../../exercises/ex-sharing.rst:641
	English ↹ ↵ NBS … “ ” ‘ ’ ﹙-﹚ ‐ – — Consider a CSMA/CD network that contains hosts that generate frames at a regular rate. When the transmission rate increases, the amount of collisions increases. For a given network load, measured in bits/sec, would the number of collisions be smaller, equal or larger with short frames than with long frames ? 309/10000 · 309
37 ../../exercises/sockets.rst:290
	English ↹ ↵ NBS … “ ” ‘ ’ ﹙-﹚ ‐ – — The port number identifying the program running on the computer 63/10000 · 63
37 ../../principles/naming.rst:152
	English ↹ ↵ NBS … “ ” ‘ ’ ﹙-﹚ ‐ – — A copy of the information maintained by each root nameserver is available at http://www.internic.net/zones/root.zone 116/10000 · 116
37 ../../exercises/network.rst:335
	English ↹ ↵ NBS … “ ” ‘ ’ ﹙-﹚ ‐ – — Host `A` uses a different flat address on each of its links 59/10000 · 59
37 ../../glossary.rst:158
	English ↹ ↵ NBS … “ ” ‘ ’ ﹙-﹚ ‐ – — The Enhanced Interior Gateway Routing Protocol (EIGRP) is a proprietary intradomain routing protocol that is often used in enterprise networks. EIGRP uses the DUAL algorithm described in [Garcia1993]_. 201/10000 · 201
37 ../../exercises/reliability.rst:73
	English ↹ ↵ NBS … “ ” ‘ ’ ﹙-﹚ ‐ – — ten frames 10/10000 · 10
37 ../../principles/referencemodels.rst:233
	English ↹ ↵ NBS … “ ” ‘ ’ ﹙-﹚ ‐ – — The OSI reference model 23/10000 · 23
37 ../../principles/network.rst:227
	English ↹ ↵ NBS … “ ” ‘ ’ ﹙-﹚ ‐ – — Some networks use the arrival of packets as the trigger to compute the corresponding entries in the forwarding tables. Several technologies have been built upon this principle. When a packet arrives, the router consults its forwarding table to find a path towards the destination. If the destination is present in the forwarding table, the packet is forwarded. Otherwise, the router needs to find a way to forward the packet and update its forwarding table. 457/10000 · 457
37 ../../principles/reliability.rst:160
	English ↹ ↵ NBS … “ ” ‘ ’ ﹙-﹚ ‐ – — Many other types of encodings have been defined to transmit information over an electrical cable. All physical layers are able to send and receive physical symbols that represent values `0` and `1`. However, for various reasons that are outside the scope of this chapter, several physical layers exchange other physical symbols as well. For example, the Manchester encoding used in several physical layers can send four different symbols. The Manchester encoding is a differential encoding scheme in which time is divided into fixed-length periods. Each period is divided in two halves and two different voltage levels can be applied. To send a symbol, the sender must set one of these two voltage levels during each half period. To send a `1` (resp. `0`), the sender must set a high (resp. low) voltage during the first half of the period and a low (resp. high) voltage during the second half. This encoding ensures that there will be a transition at the middle of each period and allows the receiver to synchronize its clock to the sender's clock. Apart from the encodings for `0` and `1`, the Manchester encoding also supports two additional symbols : `InvH` and `InvB` where the same voltage level is used for the two half periods. By definition, these two symbols cannot appear inside a frame which is only composed of `0` and `1`. Some technologies use these special symbols as markers for the beginning or end of frames. 1429/10000 · 1429
37 ../../principles/sharing.rst:233
	English ↹ ↵ NBS … “ ” ‘ ’ ﹙-﹚ ‐ – — `Which packet(s) should be discarded ?` Once the network node has decided to discard packets, it needs to actually discard real packets. 136/10000 · 136
37 ../../principles/transport.rst:97
	English ↹ ↵ NBS … “ ” ‘ ’ ﹙-﹚ ‐ – — A simple BNF specification 26/10000 · 26
37 ../../principles/security.rst:380
	English ↹ ↵ NBS … “ ” ‘ ’ ﹙-﹚ ‐ – — The public key is used to encrypt a message so that it can only be read by the intended recipient. For example, let us consider two users : Alice and Bob. Alice (resp. Bob) uses the keys :math:`A_{priv}` and :math:`A_{pub}` (resp. :math:`B_{priv}` and :math:`B_{pub}`). To send a secure message `M` to Alice, Bob computes :math:`CM=E_p(A_{pub},M)` and Alice can decrypt it by using :math:`D_p(A_{priv},CM)=D_p(A_{priv},E_p(A_{pub},M))=M`. 438/10000 · 438