5-4
MAX Administration Guide
Administering E1 and T1 Services
Troubleshooting a blinking Alarm
Troubleshooting a blinking Alarm
Without using any of the MAX 6000 or the MAX 3000 unit’s available interfaces, a blinking
Alarm helps you begin to gather information about the performance of the unit. For example,
the indicator lights can indicate that a secondary E1/PRI or T1/PRI line is disabled.
A blinking Alarm indicator light indicates that the physical configuration of the E1/PRI or T1
line is correct but the D channel is not communicating with the WAN. A D channel carries
WAN synchronization and signaling information on a T1 or T1 line. Synchronization over the
D channel helps assure that data traveling over the network does not get lost or become
jumbled. Signaling enables connections over telephone lines to be gracefully built and then
torn down. Remedy D-channel issues by verifying information with your PRI service carrier,
specifying values for several parameter settings in the Line Config profile, and verifying
whether or not the unit is equipped with an integrated Channel Service Unit (CSU).
Integrated CSU for T1/PRI
If the WAN interface or the MAX unit is not equipped with an integrated CSU, the Alarm indi-
cator light blinks. A CSU is a component of Data Circuit-terminating Equipment (DCE). A
CSU connects a digital telephone line to a customer's network-access equipment. It can be
built into the network interface of the network-access equipment, or it can be a separate device.
The CSU terminates the connection at the user's end and processes digital signals. For informa-
tion about displaying WAN interface features, such as the integrated CSU, see “Listing WAN
interface features” on page 5-7.
Specify whether or not the MAX unit uses the integrated CSU by enabling or disabling the
Front End parameter in the Line Config menu’s Line N profile. In the following example, the
Front End parameter specifies the front-end type of the T1 transceiver. For a T1 line, specify
CSU or DSX. The CSU setting specifies a Channel Service Unit, a device that ensures that
only clean signals go out on the line. For example:
10-103
Example profile
Line 1...
Sig Mode=Inband
NFAS ID num=N/A
Rob Ctl=Wink-Start
Switch Type=N/A
Framing Mode=D4
Front End=CSU
Encoding=AMI
FDL=N/A
Length=
Framing Mode parameter
specifies incorrect value
Check the specified value of the Framing Mode parameter in the Line Config
menu’s Line N profile.
Cabling problems
You might have a crossover cable installed when a straight-through cable is required,
or vice versa.
Table 5-1. Red Alarm potential causes and solutions (continued)
Cause
Solution