Nortel Media Gateway 3500 Installation, Operation And Maintenance Manual page 194

Table 17-1: Troubleshooting Faults in the Media Gateway
Problem Possible Cause(s)
Synchronization
problems - too
many alarms on the
trunks.
Trunk span settings
problems
1610 board Warm It takes up to 10
Protection: minutes to unlock
the 1610 board
(Capacity
under the following
Sustaining
circumstances:
Redundancy)
Insertion of the
same failed board
under traffic
Media Gateway It is not
management: recommended to
change Network
Changing of
settings (default
Network
gateway and
settingsMedia
subnet mask) from
EMS GUI.
State change MAC1 and MAC2
event on trunk are opposite
span #1-#8
appear on trunk
span #9-16 or vise
versa
Installation, Operation, Maintenance Manual
What to do
Verify that the clock hierarchy is set
properly. Check which clock sync mode
is being used and is set in the
appropriate mode in both the gateway,
trunks and in the systems to which the
gateway is connected. Take into
account that the clock recovery is done
from the trunk set to non-zero clock
priority. All other trunks use the
gateway clock to synchronize the trunk.
Verify trunk span settings:
type - E1/T1/J1
Framing method
Line Code
This situation is unusual because:
The failed 1610 board is usually
replaced by another one (another two
MACs)
During Weak redundancy, the
The 1610 board
redundant board goes through a reset
fails and a Weak
procedure and a ServiceChange
switch-over is
messages is issued toward the Call
performed
Agent. In this way, the Call Agent
The same TP
deletes the far-end connections talking
board (the same
to the failed 1610 board and prevents
two MACs) was
RTP traffic.
inserted
If the above doesn't occur, wait for up
There are still
to 10 minutes for a failed 1610 board
many open
Unlock/BootP completion.
connections
(more than 10
RTP streams)
toward this
board.
SC may disappear from EMS vision if
its new settings don't match the EMS
Network settings.System should not be
started without SA board being
inserted.
switch between MAC1 and MAC2
194
Media Gateway 3500
Refer to
Document # LTRT-90704