User Manual
U-SYS IAD108 Integrated Access Device
Chapter 8 Troubleshooting
8-12
b:64, e:on, s:onQ: loop,processR: G/ft(N),G/mt(N)S: X:
1200177206000C00
The softwitch of company S enabled echo cancellation (EC), and
EC operates on the peer end; therefore, an echo is heard on the PSTN
side.
8.3.3 Processing Procedure
According to the internal flow of the IAD and SoftX3000 of
Huawei, when the IAD networks through NAT, EC and VAD on the IAD
side should be set to “off”, and they should not be seen in the signaling
returned by the IAD.
After EC and VAD on the softswitch of company S are disabled,
the fault disappears and communication returns to normal.
8.4
Call Fails After Telephone Ringing
8.4.1 Fault
A carrier's networking consists of the SoftX3000 plus IAD and
TMG8010. When an IAD user calls a user of other carriers, the call
needs to go out through the TMG8010. In the local equipment room
there are an IAD and TMG8010, which connect to the LAN Switch and
router. The IAD can successfully calls a subscriber of other non-local
carriers. If the subscriber calls a subscriber of other local carriers, the
phone set of the callee can ring. However, when the callee hooks off,
there is no tone, and neither side can communicate.
8.4.2 Cause
The call signaling flow of the IAD subscriber is
“IAD--SoftX3000--TMG8010—other carriers”. Analysis of the fault
