User's Manual

APCD-LM043-4.0 135
12 Troubleshooting
Troubleshooting an LMS4000 900 MHz radio network problem is an iterative process. First of
all, you need to isolate the general location of the problem, then isolate the problem, and
finally, determine the root cause of the problem. There are five general areas to which an
LMS4000 operational problem might be isolated:
•End-user’sPC
• EUM environment
• CCU radio environment
• Operator’s network upstream from the CCU (between the CCU and the Internet)
• Internet
The key to efficient troubleshooting is first verifying that the network and equipment upstream
from the CCU is operational. This upstream network and equipment includes
• data path from the CCU to the gateway router,
• DNS servers, and
• DHCP server, if DHCP is enabled.
NOTE: The troubleshooting procedures presented in this section are
most effective if the upstream path and equipment have already
been verified.
Problems can generally be divided between those that affect all EUMs on a CCU, and those
that affect only one EUM.
A. If all EUMs are affected
• Verify that the path from the gateway router to the Internet is up.
• Verify that you can ping the CCU Ethernet port from the gateway router.
• If these tests are successful, go to CCU Troubleshooting on page 145.