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186 ../../principles/reliability.rst:959
	English ↹ ↵ NBS … “ ” ‘ ’ ﹙-﹚ ‐ – — The receiving window with selective repeat 42/10000 · 42
186 ../../principles/linkstate.rst:92
	English ↹ ↵ NBS … “ ” ‘ ’ ﹙-﹚ ‐ – — To deal with the memory corruption problem, link state packets contain a checksum or CRC. This checksum is computed by the router that generates the LSP. Each router must verify the checksum when it receives or floods an LSP. Furthermore, each router must periodically verify the checksums of the LSPs stored in its LSDB. This enables them to cope with memory errors that could corrupt the LSDB as the one that occurred in the ARPANET. 435/10000 · 435
186 ../../principles/sharing.rst:1526
	English ↹ ↵ NBS … “ ” ‘ ’ ﹙-﹚ ‐ – — In this section, we focus on congestion control mechanisms that regulate the transmission rate of the hosts. Other types of mechanisms have been proposed in the literature. For example, `credit-based` flow-control has been proposed to avoid congestion in ATM networks [KR1995]_. With a credit-based mechanism, hosts can only send packets once they have received credits from the routers and the credits depend on the occupancy of the router's buffers. 451/10000 · 451
186 ../../protocols/email.rst:305
	English ↹ ↵ NBS … “ ” ‘ ’ ﹙-﹚ ‐ – — 00010100 11111011 18/10000 · 18
186 ../../protocols/ipv6.rst:645
	English ↹ ↵ NBS … “ ” ‘ ’ ﹙-﹚ ‐ – — The broadcast service allows easily reaching all devices attached to a datalink layer network. It has been widely used to support IP version 4. A drawback of using the broadcast service to support a network layer protocol is that a broadcast frame that contains a network layer packet is always delivered to all devices attached to the datalink network, even if some of these devices do not support the network layer protocol. The multicast service is a useful alternative to the broadcast service. To understand its operation, it is important to understand how a datalink layer interface operates. In shared media LANs, all devices are attached to the same physical medium and all frames are delivered to all devices. When such a frame is received by a datalink layer interface, it compares the destination address with the MAC address of the device. If the two addresses match, or the destination address is the broadcast address, the frame is destined to the device and its payload is delivered to the network layer protocol. The multicast service exploits this principle. A multicast address is a logical address. To receive frames destined to a multicast address in a shared media LAN, a device captures all frames having this multicast address as their destination. All IPv6 nodes are capable of capturing datalink layer frames destined to different multicast addresses. 1376/10000 · 1376
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