The following administrators take care of the network and computer services in Karlín:
Jaroslav Richter | K381, 95155 3206, | user support, user account creation, computer registration |
Martin Trčka | K381, 95155 3237, | computer classrooms and computer lab K10 |
Oldřich Ulrych | K387, 95155 3216, | network and servers |
(If you are not sure who to contact, please contact any of the people above and we will pass on the information.)
Computer services for students
- computer classrooms (K4, K11) and computer lab (K10):
- access to classrooms (K4, K11) is by teacher only
- computer lab (K10) is open weekdays usually 8:00 a.m. to 8:00 p.m., there is the possibility of printing and scanning
- student accounts for logging into the computers (LABK domain) are automatically taken from the CAS system (login name must be a name, e.g. novakj, not a number; password is the same)
- for more information see //labs.karlin.mff.cuni.cz/
- connection to the internet via the eduroam Wi-Fi network (login credentials must be set up in the CAS system: Other accounts -> Set password for eduroam realm cuni.cz)
- the local branch of the faculty library also has a study room with computers: //www.mff.cuni.cz/en/library/library-services/study-rooms
Computer services for faculty, staff, PhD students, guests
- computer classrooms (K11, K4, K10A, K10B) - for access to the rooms, for setting up a teacher user account (LABK domain) or for installing the software -> Martin Trčka
- connecting to the Internet via the eduroam Wi-Fi network (login details must be set up by the user in the CAS system: Other accounts -> Set password for eduroam realm cuni.cz)
- connecting your computer to the wired network (computer registration) -> Jaroslav Richter
- Karlín user account (MSEKCE domain, see
//www.mff.cuni.cz/en/math/internal-affairs/net-and-computers/msekce) -> Jaroslav Richter, account offers:
- an e-mail box with the address (webmail, IMAP)
- possibility to have your own website
- data space with backup
- furthermore, on request (-> Jaroslav Richter) we offer:
- remote access to a terminal (Windows) or SSH (Linux) server
- VPN (remote access to local network e.g. from home)
- computing cluster (and Git) - see //cluster.karlin.mff.cuni.cz/ for information and account creation.
Note on security (phishing)
None of the Karlín administrators need to know the password to your account, and they certainly won't ask for it via email. So if you receive an email asking you to provide or enter your login credentials on some (dubious) website (or else all your data will be blocked or deleted within 24 hours), it will most likely be a phishing scam.
The only exception to this is the university's CAS system, which reminds users once a year that their password will expire in 14 days and that they should change it at //ldapuser.cuni.cz/account/password/nomenu/1. But with the administrator J. Richter or O. Ulrych, you can also change the expired password (or at least extend its validity).
If you are in doubt whether an e-mail message is genuine or whether it is a scam, feel free to contact us (the administrator).
A network consists of two or more computers that are linked in order to share resources (such as printers and CDs), exchange files, or allow electronic communications. The computers on a network may be linked through cables, telephone lines, radio waves, satellites, or infrared light beams.
Two very common types of networks include:
- Local Area Network (LAN)
- Wide Area Network (WAN)
You may also see references to a Metropolitan Area Networks (MAN), a Wireless LAN (WLAN), or a Wireless WAN (WWAN).
Local Area Network
A Local Area Network (LAN) is a network that is confined to a relatively small area. It is generally limited to a geographic area such as a writing lab, school, or building.
Computers connected to a network are broadly categorized as servers or workstations. Servers are generally not used by humans directly, but rather run continuously to provide "services" to the other computers (and their human users) on the network. Services provided can include printing and faxing, software hosting, file storage and sharing, messaging, data storage and retrieval, complete access control (security) for the network's resources, and many others.
Workstations are called such because they typically do have a human user which interacts with the network through them. Workstations were traditionally considered a desktop, consisting of a computer, keyboard, display, and mouse, or a laptop, with with integrated keyboard, display, and touchpad. With the advent of the tablet computer, and the touch screen devices such as iPad and iPhone, our definition of workstation is quickly evolving to include those devices, because of their ability to interact with the network and utilize network services.
Servers tend to be more powerful than workstations, although configurations are guided by needs. For example, a group of servers might be located in a secure area, away from humans, and only accessed through the network. In such cases, it would be common for the servers to operate without a dedicated display or keyboard. However, the size and speed of the server's processor(s), hard drive, and main memory might add dramatically to the cost of the system. On the other hand, a workstation might not need as much storage or working memory, but might require an expensive display to accommodate the needs of its user. Every computer on a network should be appropriately configured for its use.
On a single LAN, computers and servers may be connected by cables or wirelessly. Wireless access to a wired network is made possible by wireless access points (WAPs). These WAP devices provide a bridge between computers and networks. A typical WAP might have the theoretical capacity to connect hundreds or even thousands of wireless users to a network, although practical capacity might be far less.
Nearly always servers will be connected by cables to the network, because the cable connections remain the fastest. Workstations which are stationary (desktops) are also usually connected by a cable to the network, although the cost of wireless adapters has dropped to the point that, when installing workstations in an existing facility with inadequate wiring, it can be easier and less expensive to use wireless for a desktop.
See the Topology, Cabling, and Hardware sections of this tutorial for more information on the configuration of a LAN.
Wide Area Network
Wide Area Networks (WANs) connect networks in larger geographic areas, such as Florida, the United States, or the world. Dedicated transoceanic cabling or satellite uplinks may be used to connect this type of global network.
Using a WAN, schools in Florida can communicate with places like Tokyo in a matter of seconds, without paying enormous phone bills. Two users a half-world apart with workstations equipped with microphones and a webcams might teleconference in real time. A WAN is complicated. It uses multiplexers, bridges, and routers to connect local and metropolitan networks to global communications networks like the Internet. To users, however, a WAN will not appear to be much different than a LAN.