Modem faq

This faq (frequently asked questions) answers the most common questions presented to Orakeltjenesten concerning modem. If you have comments, corrections or additional information, please contact Orakeltjenesten : email, phone (735) 91500, or by contacting us directly at the office on the 1. floor of Sentralbygg II at Gløshaugen.

1. What is the NTNU dial-up service?

The dial-up service is a service for students and employees who wish to connect to NTNU's network from their home or when traveling. When you are connected to the NTNU dial-up service, you can access the same resources as when on the internal network of NTNU.

2. Who can use the dial-up service?

The dial-up service is available for all students and employees at the Norwegian University of Science and Technology. If you are denied access, you can contact Orakeltjenesten. Employees can also contact their local IT department.

3. Where can I get help?

Orakeltjenesten offers user assistance via email, telephone (735) 91500or by contacting us directly at the office on the 1. floor of Sentralbygg II at Gløshaugen. We also accept computers for installation, configuration and troubleshooting in relation to the dial-up service.

4. What is a Modem?

The word MODEM is an acronym for MOdulator DEModulator. The modem receives digital signals from a computer, and converts these signals to modulated analogue signals. These signals can then be transferred via a telephone line. A modem also receives such signals and converts them to digital signals understood by the computer.

5. What phone numbers can I call?

The number is 73 59 09 50.

6. What speed should I have between the computer and the modem?

The "Data Terminal Equipment (DTE)" speed is controlled independently from the modem speed, and this speed should be higher than the speed from the modem and out. Before a modem transfers data to another modem, it first compresses the data. And the modem receiving data decompresses the data before passing it on to the computer. This means that the amount of data transferred between two modems is smaller than the amount passing from the modem to the computer. Therefore, to ensure optimal performance, one should set the speed between the modem and the computer somewhat higher than the speed between the two modems. Maximal DTE speed is defined by the speed of your computers serial port. One should set the speed to the maximum of what the serial port (UART) can handle. On computers made after 1995, one can set this speed to 115200 bps.

7. What is an UART?

A chip called Universal Asynchronous Receiver and Transmitter (UART) is fundamental for serial data transfer. In brief, this chip converts parallel data into a serial stream of data that can be transferred over a telephone line. There are different types of UARTs, each one given a characteristic number. Common UARTs found on computers are 8250, 16450 and 16550. How fast an UART can transfer data depends on many factors. But, in general, one can say that UART 8250 supports transfer with speeds up to 19200 bps, and UART 16550 up to 115200 bps.

8. What if the connection stops before I connect to the Internet?

When does the connection stop?

First you should determine when the connection stops. Most modems have a speaker which enables you to listen to the signal as the modem tries to connect. You can also watch the status window of the modem, where you can see what commands are being sent to and received from the terminal server when contact has been made.

Does it ring?

If the connection stops before the modem reaches the terminal server you should check if the modem is switched on, if the cables are correctly connected, if the correct serial port is activated and if you have to dial 0 to get a dial tone (if so, go to question 20.).

The modem at the dial-up service does not answer

If you hear that your modem contacts one of the modems at the dial-up service without getting any answer, try again! It might be that this particular modem has not been correctly reset after a previous connection, or that there is some other problem with this modem. If you experience this problem often, contact Orakeltjenesten.

The connection "hangs"

If a connection hangs after contact between user and the dial-up service is achieved, it might be due to problems with the modem receiving your connection. If this happens, try again! If the problem continues, please contact Orakeltjenesten.

It might also be that there are problems with the configuration of your computer. First, pay attention to the information shown in your terminal window, and check if the correct login information is sent. Also, try to verify your connection settings according to the key figures and the guidelines for modem configuration.

9. Why am I asked to submit my password several times when trying to connect?

This means that the terminal server does not accept your login information. This might be because you entered the wrong password. It might also be due to problems with the TACACS server, in which case an error message will appear. Problems with this server will prevent you from logging on, since your password cannot be authenticated against BDB (NTNU's user database). If you wait a while, the server might be back online. If you are sure that your modem is correctly configured and that you typed the correct password, you should contact Orakeltjenesten immediately.

10. How can I access my email from my home computer?

You will have to configure your mail program so that it retrieves your email from the correct email server. If you want to read more about configuring your email, see Infoweb articles concerning email

11. How many modem lines are available through NTNU's dial-up service?

For students, 60 lines are available, each supporting transfer speeds up to 33,6 kbps

For employees, 32 lines are available, each supporting transfer speeds up to 33,6 kbps

12. Is this service free?

Yes. The university does not charge for this service. But you will have to pay your telephone company for the time used while connected to the terminal server. The server is located in Trondheim.

13. Where can I change the password for my dial-up account?

You can change your password in the user database. Note that you can choose between changing the password for one server alone or for all of your NTNU accounts at once

14. What cables do I need?

All the cables you need should come with your modem. Note! The cable connecting your modem with the telephone contact might be different from the cable connecting your telephone with the wall socket. If you interchange these two cables you will get no dial tone when testing the modem.

15. What computers does the dial-up service support?

Most computers and operative systems used today should be compatible with the dial-up service. Guides for configuring some of these systems are available at Infoweb pages on modem configuration.

16. Why cannot I reach servers outside the NTNU domain?

This is due to an error in your network configuration. To fix this (in windows 95), you must click the right mouse button on the icon for your dial-up connection. Choose Properties from the menu. In the properties window, choose Server type... and TCP/IP settings.... At the bottom of the TCP/IP settings window, you activate the option Use standard gateway on dialup networks.

17. How can I access my home directory from my private computer?

On Infoweb you can find information on how to connect to your home directory using WinNT/2000/XP

18. How do I log on to a NT-domain?

Windows 95, 98 and ME: Push Start -> Settings -> Control Panel -> Network -> Client for Microsoft Network and choose Logon to NT-domain. Enter the domain name (This name depends on which domain you want to log on to.) and push OK twice to save your settings. If you are asked if you want to restart the computer, answer yes.

Open My computer -> Dial-up networking, right click your connection, and choose properties. Choose the tab Server type and ensure that the Log on to network option is activated. Push TCP/IP settings... and activate Specify name server addresses. In the field Primary WINS you enter 129.241.18.16 ,and in the field Secondary WINS you enter 129.241.183.17. Push OK twice to save your settings.

You will now log on to the NT server the next time you open your dialup connection. If you experience problems when contacting the computer, it might be that the WINS-server is lacking information about your computer. If so, you will have to specify the name and IP address of your computer in the file lmhosts. This file should be placed in the C:\Windows directory. If you do not have this file, you could take a copy of lmhosts.sam by pushing Start -> Run..., enter copy C:\Windows\lmhosts.sam C:\Windows\lmhosts and push OK (Or, if you have installed windows in another catalogue, change C:\Windows\ with the correct path). Then you edit the file lmhosts using e.g. Notepad (Start -> Run... -> notepad C:\Windows\lmhosts -> OK) and enter the references that you need, e.g.:

129.241.56.11 storm

However, many computers are already registered in the WINS-server. In that case using the lmhosts file is unnecessary. Sometimes, protocols installed in Network in Control Panel earlier might create problems when trying to connect through the modem. In that case, you will have to uninstall all unnecessary protocols. For instance, installing the IPX/SPX protocol on your dial-up connection might create problems. If you need the IPX/SPX protocol for your network card, you must ensure that the protocol only associates with this card and not the modem. In order to see an overview of these bindings, see: Start -> Settings -> Control Panel -> Network -> choose relevant protocols -> Bindings.

19. Does the dial-up service support 56 kbps (X2 or K56Flex)?

No, these standards will not be supported by NTNU.

20. Why am I not getting a dial tone?

There can be many reasons for this, some of which are explained below :

• The modem cables are wrongly connected. Check that the cable between the modem and the phone socket is plugged in correctly.
• You are using an extension cord unsuited for use with modems. Try moving your computer closer to the phone socket in order to connect without the use of an extension chord. If necessary, an extension cord made specifically for modems can be bought at electronics stores.
• You try to connect through a local telephone central. Most central require a prefix to open an external line (often 0 or 9). Check that this number is added to your dial-up number. You can also add a comma between the prefix and the phone number. This will make the modem pause for a moment before dialling the main number, (e.g.: ,0,73590950). Note that not all telephone centrals handle modem traffic very well.
• You have only one phone line out of your house, and someone is ordering pizza right now....

21. If everything else fails.....

ContactOrakeltjenesten on email, telephone (735) 91500 or by enquiry at the service point on the 1. floor of Sentralbygg II at Gløshaugen.