I can't use the Internet through Missouri State University's dial up because I keep
getting dropped. This often happens within the first few minutes or even seconds of
the call. What can be done to fix this?
February 12, 2000
Additional trouble shooting information may be found in Dialup
Troubleshooting.
February 9, 1999
New information was uncovered late yesterday with newly purchased and installed
modems which can cause failures to connect, unexplained disconnects, poor V.34 or lower
data rate connections, and non-existent V.90 (56K) service. Please read news item
New MICA modems prove to be problematic
for more information. NOTE: These "defective"
modems are no longer in service. (5-6-99)
January 15, 1999
Modem disconnect problems cannot usually be affected at the central site unless it is
running out-of-date code (which Missouri State University is not) or unless digital trunk problems exist.
Sometimes our communication server vendor, Cisco, will patch their code to circumvent
specific problems with other vendor's modems. They will also occasionally find
problems with their code and will issue maintenance releases of code to fix these
problems. We will work with users and Cisco in rare circumstances to resolve
interoperability issues where appropriate. Feel free to contact us after reading and
trying the following:
Possible problems and solutions:
| PROBLEM |
Your modem could be running early development code and not real production code.
|
| SOLUTION |
Contact your modem manufacturer and update the modem’s firmware to the latest
level. If they care (which they probably won’t), tell them that you are
connecting to Cisco AS5200 or AS5300 communication servers with Microcom
modems
running V.90 release code. Our servers are kept up to the latest level: we
just completed another upgrade on 2-5-1999. |
| |
|
| PROBLEM |
The user’s modem negotiates a baud rate higher than the line can be supported by
the phone connection. When line errors occur, the modem fails to retrain and the
connection is dropped. |
| SOLUTION |
Try forcing your modem to connect a lower baud rate. This will be done through
commands specific to your brand of modem, so we can't help you with the actual commands.
If you normally connect at 44,000 baud, try forcing the modem to connect at 40,000
or less. |
| |
|
| PROBLEM |
You may have poor quality phone service. Missouri State University uses high quality digital trunks
which can support the full transmission speeds used by our modems. Most user's lines
are analog which are subject to various interferences. Usually these problems result
in lower connect rates, but can cause drops. |
| SOLUTION |
Contact your telephone carrier and have them check the lines. SWBT will do this
for free, but will charge for most improvements on a case-by-case basis. Our news
item on V.90 modem support might help
here as well. |
| |
|
| PROBLEM |
Your modem may be damaged or defective. |
| SOLUTION |
Connect to other service providers (if available) to see if you have similar problems
(if not, this does not automatically indicate the problem is at Missouri State University.) This author
personally had this very problem: My modem would connect and drop within minutes or
even seconds. Dropping to lower baud rates had no effect. I replaced the older
28.8K modem with a new V.90 modem and the problem went away completely! My
connection rate, unfortunately, stayed at only 28.8K although I could dial from St.
John’s hospital and get a consistent 44K. |
|
|
| PROBLEM |
The digital trunks from Southwestern Bell or GTE may be experiencing clocking problems. |
| SOLUTION |
Missouri State University Networking Staff monitors the operation of the communication servers and line
trunk condition. Thus far, we have never had any problems with clocking or other
trunk failures. However, if you have tried all of the above, feel free to report
excessive drops to the Computer Services Help Desk by
using the previous link or by calling 417-836-5891. We will receive the information
and check the trunks. |
|
