2. cnp3-ebook
3. English
4. Zen

66 ../../principles/network.rst:390
	English ↹ ↵ NBS … “ ” ‘ ’ ﹙-﹚ ‐ – — Dealing with heterogeneous datalink layers 42/10000 · 42
66 ../../principles/reliability.rst:249
	English ↹ ↵ NBS … “ ” ‘ ’ ﹙-﹚ ‐ – — `0` : `0110000` b 17/10000 · 17
66 ../../principles/sharing.rst:402
	English ↹ ↵ NBS … “ ” ‘ ’ ﹙-﹚ ‐ – — `Time Division Multiplexing` (TDM) is a static bandwidth allocation method that was initially defined for the telephone network. In the fixed telephone network, a voice conversation is usually transmitted as a 64 Kbps signal. Thus, a telephone conservation generates 8 KBytes per second or one byte every 125 microseconds. Telephone conversations often need to be multiplexed together on a single line. For example, in Europe, thirty 64 Kbps voice signals are multiplexed over a single 2 Mbps (E1) line. This is done by using `Time Division Multiplexing` (TDM). TDM divides the transmission opportunities into slots. In the telephone network, a slot corresponds to 125 microseconds. A position inside each slot is reserved for each voice signal. The figure below illustrates TDM on a link that is used to carry four voice conversations. The vertical lines represent the slot boundaries and the letters the different voice conversations. One byte from each voice conversation is sent during each 125 microseconds slot. The byte corresponding to a given conversation is always sent at the same position in each slot. 1115/10000 · 1115
66 ../../principles/transport.rst:251
	English ↹ ↵ NBS … “ ” ‘ ’ ﹙-﹚ ‐ – — the `connection oriented service` 33/10000 · 33
66 ../../principles/security.rst:799
	English ↹ ↵ NBS … “ ” ‘ ’ ﹙-﹚ ‐ – — In this exchange, Bob authenticates himself by signing the :math:`RA` nonce that was sent by Mallory. Now, to authenticate as Alice, Mallory needs to compute the signature of nonce :math:`RB` with Alice's private key. Mallory does not know Alice's key, but he could exploit the protocol to force Alice to perform the required computation. For this, Mallory can start an authentication to Alice as shown below. 409/10000 · 409
66 ../../exercises/ipv6.rst:613
	English ↹ ↵ NBS … “ ” ‘ ’ ﹙-﹚ ‐ – — ``2001:db8:1341:13::/64`` on the link between ``r1`` and ``r3`` 63/10000 · 63
66 ../../exercises/routing-protocols.rst:900
	English ↹ ↵ NBS … “ ” ‘ ’ ﹙-﹚ ‐ – — We can now disable one of the BGP sessions on router `as2` as follows. 70/10000 · 70
66 ../../exercises/tcp-2.rst:883
	English ↹ ↵ NBS … “ ” ‘ ’ ﹙-﹚ ‐ – — packetdrill_ requires root privileges since it inject raw IP packets. The easiest way to install it is to use a virtualbox image with a Linux kernel 4.x or 5.x. You can clone its git repository from https://github.com/google/packetdrill and follow the instructions in https://github.com/google/packetdrill/tree/master/gtests/net/packetdrill. The packetdrill_ scripts used in this section are available from https://github.com/cnp3/ebook/tree/master/exercises/packetdrill_scripts 478/10000 · 478
66 ../../protocols/bgp.rst:281
	English ↹ ↵ NBS … “ ” ‘ ’ ﹙-﹚ ‐ – — the advertised prefix 21/10000 · 21
66 ../../protocols/email.rst:236 • ../../protocols/email.rst:238
	English ↹ ↵ NBS … “ ” ‘ ’ ﹙-﹚ ‐ – — 2 1/10000 · 1
66 ../../protocols/ethernet.rst:305
	English ↹ ↵ NBS … “ ” ‘ ’ ﹙-﹚ ‐ – — The `MAC address learning` algorithm allows switches to be plug-and-play. Unfortunately, the loops that arise when the network topology is not a tree are a severe problem. Forcing the switches to only be used in tree-shaped networks as hubs would be a severe limitation. To solve this problem, the inventors of Ethernet switches have developed the `Spanning Tree Protocol`. This protocol allows switches to automatically disable ports on Ethernet switches to ensure that the network does not contain any cycle that could cause frames to loop forever. 550/10000 · 550
66 ../../protocols/http.rst:309
	English ↹ ↵ NBS … “ ” ‘ ’ ﹙-﹚ ‐ – — The `Keep-Alive:` header is used by the server to inform the client about how it agrees to use the persistent connection. A typical `Keep-Alive:` contains two parameters: the maximum number of requests that the server agrees to serve on the underlying TCP connection and the timeout (in seconds) after which the server will close an idle connection 348/10000 · 348
66 ../../protocols/ipv6.rst:225
	English ↹ ↵ NBS … “ ” ‘ ’ ﹙-﹚ ‐ – — The longest prefix match can be implemented by using different data structures One possibility is to use a trie. Details on how to implement efficient packet forwarding algorithms may be found in [Varghese2005]_. 212/10000 · 212
66 ../../protocols/ethernet.rst:199
	English ↹ ↵ NBS … “ ” ‘ ’ ﹙-﹚ ‐ – — The attentive reader may question the need for different `EtherTypes` for IPv4 and IPv6 while the IP header already contains a version field that can be used to distinguish between IPv4 and IPv6 packets. Theoretically, IPv4 and IPv6 could have used the same `EtherType`. Unfortunately, developers of the early IPv6 implementations found that some devices did not check the version field of the IPv4 packets that they received and parsed frames whose `EtherType` was set to `0x0800` as IPv4 packets. Sending IPv6 packets to such devices would have caused disruptions. To avoid this problem, the IETF decided to apply for a distinct `EtherType` value for IPv6. Such a choice is now mandated by :rfc:`6274` (section 3.1), although we can find a funny counter-example in :rfc:`6214`. 779/10000 · 779
66 ../../protocols/tcp.rst:223
	English ↹ ↵ NBS … “ ” ‘ ’ ﹙-﹚ ‐ – — The TCP options are encoded by using a Type Length Value format where : 71/10000 · 71
66 ../../protocols/tls.rst:341
	English ↹ ↵ NBS … “ ” ‘ ’ ﹙-﹚ ‐ – — TLS supports several methods to encrypted records. The selected method depends on the cryptographic algorithms that have been negotiated for the TLS session. A detailed presentation of the different methods that can be used to produce the `TLSPlainText` from the user data is outside the scope of this book. As an example, we study one method: Stream Encryption. This method is used with cryptographic algorithms which can operate on a stream of bytes. The method starts with a sequence of bytes provided by the user application: the plain text. The first step is to compute the authentication code to verify the integrity of the data. For this, TLS computes :math:`MAC(SeqNum, Header, PlainText)` using HMAC where `SeqNum` is a sequence number which is incremented by one for each new TLS record transmitted. The `Header` is the header of the TLS record described above and `PlainText` is the information that needs to be encrypted. Note that the sequence number is maintained at the two endpoints of the TLS session, but it is not transmitted inside the TLS record. This sequence number is used to prevent replay attacks. 1123/10000 · 1123
66 ../../bibliography.rst:87
	English ↹ ↵ NBS … “ ” ‘ ’ ﹙-﹚ ‐ – — Griffin, T. G. and Wilfong, G., `An analysis of BGP convergence properties <http://doi.acm.org/10.1145/316194.316231>`_. SIGCOMM Computer Communication Review 29, 4 (Oct. 1999), 277-288. 186/10000 · 186
67 ../../exercises/network.rst:381
	English ↹ ↵ NBS … “ ” ‘ ’ ﹙-﹚ ‐ – — Consider a distance vector protocol using split horizon and `periodic updates`. Assume that the link `B-C` fails. `B` and `C` update their local routing table but they will only advertise it at the end of their period. Select one ordering for the `periodic updates` and every time a router sends its distance vector, indicate the vector sent to each neighbor and update the table above. How many periods are required to allow the network to converge to a stable state ? 470/10000 · 470
67 ../../bibliography.rst:89
	English ↹ ↵ NBS … “ ” ‘ ’ ﹙-﹚ ‐ – — Garcia-Lunes-Aceves, J., `Loop-Free Routing Using Diffusing Computations <https://dx.doi.org/10.1109/90.222913>`_, IEEE/ACM Transactions on Networking, Vol. 1, No, 1, Feb. 1993 176/10000 · 176
67 ../../glossary.rst:146
	English ↹ ↵ NBS … “ ” ‘ ’ ﹙-﹚ ‐ – — Interior Gateway Protocol. Synonym of intradomain routing protocol 66/10000 · 66