User manual
Table Of Contents
- Table of Contents
- About This Guide
- Introduction
- ISDN LAN Modem Functionality Description
- Hardware Description and Installation
- Setting Up TCP/IP for Windows and Macintosh
- Configuring the ISDN LAN Modem
- Advanced Configuration
- Before you Begin
- Setting Up Additional Service Providers
- Editing Service Provider Profiles
- Restricting Workstations from Accessing Service Provider(s)
- Configuring Your LAN Parameters
- Changing Data Call Parameters
- Changing Voice Call Routing
- Reserving DHCP Addresses
- Selective Password Protection
- Changing Your Password
- Setting Up Your ISDN Line Manually
- Locking and Unlocking the Configuration
- Configuring the ISDN LAN Modem from a Remote Location
- Supplementary Voice Call Services
- Placing, Receiving and Disconnecting Calls
- Troubleshooting and Maintenance
- Networking Primer
- What is a network?
- What is a LAN?
- What is a WAN?
- How does a LAN connect to a WAN?
- What is a LAN modem?
- What is ISDN?
- How do different devices communicate with each other?
- What is TCP/IP?
- What is an IP Address?
- What is a Subnet Mask?
- Dynamic and Static IP Addresses
- What is DHCP?
- What is DNS?
- What is NAT?
- What are numbered and unnumbered links?
- How is overall throughput determined?
- What is a network?
- Using the Custom Web Browser
- ISDN LAN Modem Factory Defaults
- ISDN LAN Modem Specifications
- Ordering ISDN Service
- If You Place Your ISDN Order Through 3Com
- If You Place Your ISDN Order Through the Telephone Company
- Supplementary Voice Features Included with U, EZ-ISDN-1, V and EZ-ISDN 1A
- Limitations of ISDN Ordering Codes U, EZ-ISDN 1, V and EZ-ISDN 1A
- What If I Already Have ISDN Service?
- Table of ISDN Ordering Code Capabilities
- Glossary
- Index
- 3Com Corporation Limited Warranty
92 C
HAPTER
9: T
ROUBLESHOOTING
AND
M
AINTENANCE
Monitoring LEDs
If you are experiencing operational inconsistencies, monitor the ALERT, ISDN,
B channel and LAN port status LEDs to isolate problems. Refer to Table 5 for
instructions to resolve the problem.
Monitoring the ALERT
LED
Press and release the
Reset
button and observe the ALERT LED. During power-up
self-test, the ALERT LED will remain lit.
■
If the ALERT LED goes out, the test has been successful.
■
If the ALERT LED flashes for more than several seconds, this indicates one of
the following:
■
Voice Mail messages pending (if you subscribe to Voice Mail)
■
ISDN LAN Modem is in firmware download mode
■
The DHCP server is full and cannot assign any more IP addresses
■
There is an internal failure (the ISDN LAN Modem also resets itself)
Voice Mail message indication uses a slower flash than firmware download and
internal failure indication. If the ISDN LAN Modem is neither in firmware
download mode nor do you have voice mail messages, notify your reseller that
the ISDN LAN Modem has failed the self-test and order a replacement.
Monitoring the ISDN
LED
Place a call and then observe the ISDN LED. One of the following three conditions
may occur:
If the ISDN flashes and then remains lit, your ISDN line is functioning properly.
If the ISDN LED never turns on, check the ISDN cable. Ensure that it is connected
securely to the wall outlet and the ISDN LAN Modem’s ISDN port. If the ISDN LED
still is not lit, there may be a problem with your ISDN line.
If the ISDN LED flashes but does not remain lit, first make sure that your ISDN
telephone numbers and SPIDs are configured accurately (click
ISDN Parameters
from the WebWizard main page). If your telephone numbers are configured
correctly, check with your telephone company. There may be a problem with your
ISDN line.
Monitoring the
B Channel LEDs
If the ISDN LED is illuminated, attempt to place a call and observe the B channel
LED(s). The B1 and B2 LEDs flash amber for a voice call or green for a data call
during the call establishment phase and then blinks faster during the PPP
establishment phase. They then remain solid amber or green once the connection
is established. If they do not remain solid amber or green, refer to the
“Troubleshooting Problems Indicated by LEDs” section.
Monitoring the LAN Port
Status LEDs
Observe the LAN port status LED labeled 1, 2, 3, or 4 depending on the port
number to which your computer is connected. If the LED(s) is lit, the ISDN LAN
Modem detects the Ethernet link signal and operation is normal. When the
computer attached to that port is transmitting data to the LAN, this LED flashes.
If the port status LED is Off, the ISDN LAN Modem does not detect the Ethernet
link integrity signal. Refer to the “Troubleshooting Problems Indicated by LEDs”
section. First ensure that the workstation is powered on. If so, then the Ethernet
cable may not be properly connected, or it may be the wrong polarity.