Exit Zen
4
../../protocols/transport.rst:13
English
The Real Time Transport Protocol (RTP), defined in :rfc:`3550` is another important protocol that is used by many multimedia applications. It includes functions that belong to the transport layer, but also functions that are related to the encoding of the information. Due to space limitations, we do not discuss it in this section.
0/3320 · 332
4
../../protocols/udp.rst:14
English
the UDP service does not guarantee the delivery of SDUs (losses can occur and SDUs can arrive out-of-sequence)
0/1100 · 110
4
../../protocols/wifi.rst:13
English
While most of the frequency ranges of the radio spectrum are reserved for specific applications and require a special license, there are a few exceptions. These exceptions are known as the `Industrial, Scientific and Medical <http://en.wikipedia.org/wiki/ISM_band>`_ (ISM) radio bands. These bands can be used for industrial, scientific and medical applications without requiring a license from the regulator. For example, some radio-controlled models use the 27 MHz ISM band and some cordless telephones operate in the 915 MHz ISM. In 1985, the 2.400-2.500 GHz band was added to the list of ISM bands. This frequency range corresponds to the frequencies that are emitted by microwave ovens. Sharing this band with licensed applications would have likely caused interference, given the large number of microwave ovens that are used. Despite the risk of interference with microwave ovens, the opening of the 2.400-2.500 GHz allowed the networking industry to develop several wireless network techniques to allow computers to exchange data without using cables. In this section, we discuss in more detail the most popular one, i.e. the WiFi [IEEE802.11]_ family of wireless networks. Other wireless networking techniques such as `BlueTooth <http://en.wikipedia.org/wiki/BlueTooth>`_ or `HiperLAN <http://en.wikipedia.org/wiki/HiperLAN>`_ use the same frequency range.
0/13650 · 1365
5
../../bibliography.rst:14
English
LAN/MAN Standards Committee of the IEEE Computer Society. IEEE Standard for Information technology--Telecommunications and information exchange between systems--Local and metropolitan area networks--Specific requirements--Part 5: Token Ring Access Method and Physical Layer Specification. IEEE, 1998. available from http://standards.ieee.org/getieee802
0/3520 · 352
5
../../glossary.rst:185
English
Additive Increase, Multiplicative Decrease. A rate adaption algorithm used notably by TCP where a host additively increases its transmission rate when the network is not congested and multiplicatively decreases when congested is detected.
0/2380 · 238
5
../../exercises/ex-sharing.rst:42
English
If the transmitting host is located at another position on the shared medium than one of the edges, then the geometrical pattern that represents the transmission of a frame is slightly different. If the transmitting host is placed in the middle of the cable, then the signal is transmitted in both directions on the cable. The figure below shows the transmission of one 100 bits frame at 100 Mbps by host C on the same cable.
0/4250 · 425
5
../../exercises/reliability.rst:19
English
How would you set the duration of the retransmission timer in the alternating bit protocol ?
92/920 · 92
5
../../exercises/network.rst:42
English
Same question as above, but the network is modified as shown in the figure below.
110/810 · 81
5
../../exercises/sockets.rst:100
English
The socket API is quite low-level and should be used only when you need a complete control of the network access. If your application simply needs, for instance, to retrieve data from a web server, there are much simpler and higher-level APIs.
293/2430 · 243
5
../../exercises/transport.rst:18
English
A reliable connection oriented transport places a 32 bits sequence number inside the segment header to number the segments. This sequence number is incremented for each data segment. The connection starts as shown in the figure below :
262/2350 · 235
5
../../principles/naming.rst:15
English
Because names are at a higher level than addresses, they allow (both in the example of programming above, and on the Internet) to treat addresses as mere technical identifiers, which can change at will. Only the names are stable.
280/2290 · 229
5
../../principles/referencemodels.rst:21
English
Our reference model is divided into five layers, as shown in the figure below.
91/780 · 78
5
../../principles/network.rst:18
English
Before explaining the operation of the network layer, it is useful to remember the characteristics of the service provided by the `datalink` layer. There are many variants of the datalink layer. Some provide a reliable service while others do not provide any guarantee of delivery. The reliable datalink layer services are popular in environments such as wireless networks where transmission errors are frequent. On the other hand, unreliable services are usually used when the physical layer provides an almost reliable service (i.e. only a negligible fraction of the frames are affected by transmission errors). Such `almost reliable` services are frequently used in wired and optical networks. In this chapter, we will assume that the datalink layer service provides an `almost reliable` service since this is both the most general one and also the most widely deployed one.
996/8770 · 877
5
../../principles/reliability.rst:33
English
`electrical cable`. Information can be transmitted over different types of electrical cables. The most common ones are the twisted pairs (that are used in the telephone network, but also in enterprise networks) and the coaxial cables (that are still used in cable TV networks, but are no longer used in enterprise networks). Some networking technologies operate over the classical electrical cable.
492/3980 · 398
5
../../principles/security.rst:48
English
Alice and Bob are the first names that are used in examples for security techniques. They first appeared in a seminal paper by Diffie and Hellman [DH1976]_. Since then, Alice and Bob are the most frequently used names to represent the users who interact with a network. Other characters such as Eve or Mallory have been added over the years. We will explain their respective roles later.
0/3870 · 387
5
../../exercises/dns.rst:25
English
Several software tools can be used to send queries to DNS servers. For this exercise, we use dig_ which is installed on most Unix/Linux systems.
0/1440 · 144
5
../../exercises/email.rst:11
English
it is possible to test a server manually by using telnet
0/560 · 56
5
../../exercises/http.rst:21
English
What is the version of HTTP used by your version of curl_ ?
0/590 · 59
5
../../exercises/ipv6.rst:20
English
Now that you master the basics, you can determine the paths followed by IPv6 packets in simple networks.
0/1040 · 104
5
../../exercises/lan.rst:28
English
Consider the switched network shown in Fig. 1. In this network, assume that the LAN between switches S3 and S12 fails. How should the switches update their port/address tables after the link failure ?
0/2000 · 200