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186 ../../protocols/wifi.rst:160
	English ↹ ↵ NBS … “ ” ‘ ’ ﹙-﹚ ‐ – — In fact, the [IEEE802.11]_ frame format contains a fourth optional address field. This fourth address is only used when an 802.11 wireless network is used to interconnect bridges attached to two classical LAN networks. 218/10000 · 218
186 ../../protocols/tcp.rst:625
	English ↹ ↵ NBS … “ ” ‘ ’ ﹙-﹚ ‐ – — This 32 bits counter was specified in :rfc:`793`. A 32 bits counter that is incremented every 4 microseconds wraps in about 4.5 hours. This period is much larger than the Maximum Segment Lifetime that is fixed at 2 minutes in the Internet (:rfc:`791`, :rfc:`1122`). 265/10000 · 265
187 ../../glossary.rst:89
	English ↹ ↵ NBS … “ ” ‘ ’ ﹙-﹚ ‐ – — User Datagram Protocol is a protocol of the transport layer in the TCP/IP protocol suite that provides an unreliable connectionless service that includes a mechanism to detect corruption 186/10000 · 186
187 ../../principles/reliability.rst:961
	English ↹ ↵ NBS … “ ” ‘ ’ ﹙-﹚ ‐ – — A `selective repeat` receiver discards all frames having an invalid CRC, and maintains the variable `lastack` as the sequence number of the last in-sequence frame that it has received. The receiver always includes the value of `lastack` in the acknowledgments that it sends. Some protocols also allow the `selective repeat` receiver to acknowledge the out-of-sequence frames that it has received. This can be done for example by placing the list of the correctly received, but out-of-sequence frames in the acknowledgments together with the `lastack` value. 557/10000 · 557
187 ../../principles/linkstate.rst:94
	English ↹ ↵ NBS … “ ” ‘ ’ ﹙-﹚ ‐ – — Flooding is illustrated in the figure below. By exchanging HELLO messages, each router learns its direct neighbors. For example, router `E` learns that it is directly connected to routers `D`, `B` and `C`. Its first LSP has sequence number `0` and contains the directed links `E->D`, `E->B` and `E->C`. Router `E` sends its LSP on all its links and routers `D`, `B` and `C` insert the LSP in their LSDB and forward it over their other links. 441/10000 · 441
187 ../../principles/sharing.rst:1528
	English ↹ ↵ NBS … “ ” ‘ ’ ﹙-﹚ ‐ – — For example, the measurements performed in the Sprint network in 2004 reported more than 10k active TCP connections on a link, see https://research.sprintlabs.com/packstat/packetoverview.php. More recent information about backbone links may be obtained from caida_ 's real-time measurements, see e.g. http://www.caida.org/data/realtime/passive/ 345/10000 · 345
187 ../../protocols/email.rst:307
	English ↹ ↵ NBS … “ ” ‘ ’ ﹙-﹚ ‐ – — 000101 001111 101100 20/10000 · 20
187 ../../protocols/ipv6.rst:649
	English ↹ ↵ NBS … “ ” ‘ ’ ﹙-﹚ ‐ – — Interactions between IPv6 and the datalink layer 48/10000 · 48
187 ../../protocols/tcp.rst:627
	English ↹ ↵ NBS … “ ” ‘ ’ ﹙-﹚ ‐ – — On many departmental networks containing Unix workstations, it was common to allow users on one of the hosts to use ``rlogin`` :rfc:`1258` to run commands on any of the workstations of the network without giving any password. In this case, the remote workstation "authenticated" the client host based on its IP address. This was a bad practice from a security viewpoint. 371/10000 · 371
188 ../../glossary.rst:18
	English ↹ ↵ NBS … “ ” ‘ ’ ﹙-﹚ ‐ – — unicast 7/10000 · 7
188 ../../principles/reliability.rst:963
	English ↹ ↵ NBS … “ ” ‘ ’ ﹙-﹚ ‐ – — When a `selective repeat` receiver receives a data frame, it first verifies whether the frame is inside its receiving window. If yes, the frame is placed in the receive buffer. If not, the received frame is discarded and an acknowledgment containing `lastack` is sent to the sender. The receiver then removes all consecutive frames starting at `lastack` (if any) from the receive buffer. The payloads of these frames are delivered to the user, `lastack` and the receiving window are updated, and an acknowledgment acknowledging the last frame received in sequence is sent. 572/10000 · 572
188 ../../principles/linkstate.rst:157
	English ↹ ↵ NBS … “ ” ‘ ’ ﹙-﹚ ‐ – — Flooding allows LSPs to be distributed to all routers inside the network without relying on routing tables. In the example above, the LSP sent by router `E` is likely to be sent twice on some links in the network. For example, routers `B` and `C` receive `E`'s LSP at almost the same time and forward it over the `B-C` link. To avoid sending the same LSP twice on each link, a possible solution is to slightly change the pseudo-code above so that a router waits for some random time before forwarding a LSP on each link. The drawback of this solution is that the delay to flood an LSP to all routers in the network increases. In practice, routers immediately flood the LSPs that contain new information (e.g. addition or removal of a link) and delay the flooding of refresh LSPs (i.e. LSPs that contain exactly the same information as the previous LSP originating from this router) [FFEB2005]_. 894/10000 · 894
188 ../../protocols/email.rst:309
	English ↹ ↵ NBS … “ ” ‘ ’ ﹙-﹚ ‐ – — 5 15 44 15/10000 · 15
188 ../../protocols/ipv6.rst:653
	English ↹ ↵ NBS … “ ” ‘ ’ ﹙-﹚ ‐ – — IPv6 hosts and routers frequently interact with the datalink layer service. To understand the main interactions, it is useful to analyze all the packets that are exchanged when a simple network containing a few hosts and routers is built. Let us first start with a LAN containing two hosts [#fMAC]_. 299/10000 · 299
188 ../../protocols/tcp.rst:634
	English ↹ ↵ NBS … “ ” ‘ ’ ﹙-﹚ ‐ – — Of course, such a simultaneous TCP establishment can only occur if the source port chosen by the client is equal to the destination port chosen by the server. This may happen when a host can serve both as a client as a server or in peer-to-peer applications when the communicating hosts do not use ephemeral port numbers. 321/10000 · 321
189 ../../glossary.rst:20
	English ↹ ↵ NBS … “ ” ‘ ’ ﹙-﹚ ‐ – — a transmission mode where an information is sent from one source to one recipient 81/10000 · 81
189 ../../principles/reliability.rst:965
	English ↹ ↵ NBS … “ ” ‘ ’ ﹙-﹚ ‐ – — The `selective repeat` sender maintains a sending buffer that can store up to `W` unacknowledged frames. These frames are sent as long as the sending buffer is not full. Several implementations of a `selective repeat` sender are possible. A simple implementation associates one retransmission timer to each frame. The timer is started when the frame is sent and canceled upon reception of an acknowledgment that covers this frame. When a retransmission timer expires, the corresponding frame is retransmitted and this retransmission timer is restarted. When an acknowledgment is received, all the frames that are covered by this acknowledgment are removed from the sending buffer and the sliding window is updated. 714/10000 · 714
189 ../../principles/linkstate.rst:159
	English ↹ ↵ NBS … “ ” ‘ ’ ﹙-﹚ ‐ – — To ensure that all routers receive all LSPs, even when there are transmissions errors, link state routing protocols use `reliable flooding`. With `reliable flooding`, routers use acknowledgments and if necessary retransmissions to ensure that all link state packets are successfully transferred to each neighboring router. Thanks to reliable flooding, all routers store in their LSDB the most recent LSP sent by each router in the network. By combining the received LSPs with its own LSP, each router can build a graph that represents the entire network topology. 563/10000 · 563
189 ../../protocols/email.rst:311
	English ↹ ↵ NBS … “ ” ‘ ’ ﹙-﹚ ‐ – — F P s \= 22/10000 · 22
189 ../../protocols/ipv6.rst:671
	English ↹ ↵ NBS … “ ” ‘ ’ ﹙-﹚ ‐ – — Hosts ``A`` and ``B`` are attached to the same datalink layer network. They can thus exchange frames by using the MAC addresses shown in the figure above. To be able to use IPv6 to exchange packets, they need to have an IPv6 address. One possibility would be to manually configure an IPv6 address on each host. However, IPv6 provides a better solution thanks to the `link-local` IPv6 addresses. A `link-local` IPv6 address is an address that is composed by concatenating the ``fe80:://64`` prefix with the MAC address of the device. In the example above, host A would use IPv6 `link-local` address ``fe80::0223:45FF:FE67:89ab`` and host B ``fe80::0234:56FF:FE78:9abc``. With these two IPv6 addresses, the hosts can exchange IPv6 packets. 737/10000 · 737