You are a network technician with many years’ experience. Many users complain that they can
hear echo when their calls go out an H.323 gateway. You have made some testing for the
gateway and have changed the configuration. So the ERL level turns to be 6 dB. Furthermore, the
echo-cancel coverage value is raised to 64 ms. Please choose the effect on the voice quality after
this modification.

A.
Consonants will be chopped by the echo canceller.

B.
The increase in echo-cancel coverage will have no effect on voice quality.

C.
The ends of sentences will be chopped by the echo canceller.

D.
The echo canceller will take 2-3 seconds longer to converge at the beginning of the call.

Explanation:
echo-cancel coverage command Adjusts the coverage size of the echo canceller. This command
enables cancellation of voice that is sent out through the interface and received back on the same
interface within the configured amount of time. If thelocal loop (the distance from the interface to
the connected equipment that is producing the echo) is longer, the configured value of this
command should be extended. If you configure a longer value for this command, it takes the echo
canceller longer to converge. In this case, the user might hear a slight echo when the connection
is initially set up. If the configured value for this command is too short, the user might hear some

echo for the duration of the call because the echo canceller is not canceling the longer-delay
echoes. There is no echo or echo cancellation on the network side (for example, the non-POTS
side of the connection).