Technical information

Frequently Asked Questions (FAQs)
22
Q45. Modems make only a high-pitched whirring sound when they
negotiate, preventing users from connecting. What could be
the problem?
A45. The method of troubleshooting this symptom depends on what type of digital line
you have. If you have a PRI line, skip to the last paragraph of this answer.
For T1, this is most likely a T1 card configuration problem. The digital signaling
is probably not correct between the T1 switch and your CommPlete Server’s T1
card.
To troubleshoot this issue, check the status of your T1 card. Telnet to the
controller and log in as the supervisor. At the # prompt, type T1STATUS xn,
where x is the slot in which the T1 is located and n is “b” for the top T1 card or “c”
for the bottom T1 card. (Use “b” for n if you have only one T1 card in the
segment.) The following example illustrates the T1STATUS command:
[2] A:\ # T1STATUS 1C
Getting T1 Card Info .......
T1 Card Status:
Wink High Time (ms):220
After Wink Time (ms):500
PreWink Time (ms):220
Disconnect Timeout (sec):11
Framing Format:DS1 AT&T Extended Super Frame (ESF)
Line Coding:Binary 8 Zero Substitution (B8ZS)
FXS Signaling Options:E&M Immediate Start
Transmit Level:- 0.0dB
Receive Level:+2.0dB to –7.5dB
LED Information:Online
Model:RAS9600-T1
Version:1.07C/1.06
[3] A:\ #
The controller will display the status of the T1 card. The Framing Format, Line
Coding, and FXS Signaling options must match the provisioning of the T1 line.
The Transmit Level must be zero. If any of these settings do not match your T1
provisioning, type T1SETUP xn to change them. After making changes, reset the
T1 card using the RS xn command.
An operational T1 card will show an LED Status of “Online” and will report its
firmware version correctly.
For PRI, you need to configure the modems for the appropriate method of voice
compression used over the PRI network in your geographic region. In North
America, the PRI card uses “µ-law” compression, which the modems use by
default and do not need to be changed. In Europe, however, “a-law”
compression is the norm, and the modems need the following initialization string
to work properly: “AT&&R0826,0440S108=1”. You need to combine this string
with the init string that you are currently using, or if you are using RASExpress,
make this string a second init string. See Q19 for how to change the initialization
strings in RASExpress.