R2511-HP MSR Router Series Voice Configuration Guide(V5)

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Configuring call services
More and more VoIP-based services are demanded as voice application environments expand. On the
basis of basic calls, new features are implemented to meet different application requirements of VoIP
subscribers.
Call waiting
When subscriber C calls subscriber A who is already engaged in a call with subscriber B, the call will
not be rejected if call waiting is enabled. Just like a normal call, subscriber C will hear ringback tones,
while subscriber A will hear call waiting tones as a reminder that a call is waiting on the line.
Subscriber A can answer the new call by pressing the flash hook or hanging up to end the call with
subscriber B. In the former case, subscriber B is held. In the latter case, subscriber A is immediately
alerted and can pick up the phone to answer the call originated by subscriber C (the waiting call).
Call hold
If subscriber A in a conversation with subscriber B presses the flash hook, the media session of subscriber
B is temporarily cut through and is held (in silent state or listening to waiting tones). The system plays
silent tones or dial tones to subscriber A, depending on the configuration. (The system first plays dial
tones and waits for the subscriber to dial. If the subscriber fails to dial within a period of time, the system
stops playing dial tones and the line stays on hold.). Subscriber A can resume the call with subscriber B
by pressing the flash hook again.
After pressing the flash hook, subscriber A hears dial tones and can initiate a new call. The setup flow
for the new call is the same as the one for ordinary calls.
Call forwarding
When the called party cannot answer the call, after receiving a session request, the called party notifies
in a response the calling party of the forwarded-to number. Then the calling party re-initiates a session
request to the new destination. This is call forwarding.
The system supports the following types of call forwarding:
• Call forwarding unconditional—With this feature enabled on a voice subscriber line, incoming
calls will be forwarded to the predetermined destination, whether or not the voice subscriber line is
available.
• Call forwarding busy—With this feature enabled on a voice subscriber line, an incoming call will
be forwarded to the predetermined destination when the voice subscriber line is busy.
• Call forwarding no reply—With this feature enabled on a voice subscriber line, an incoming call
will be forwarded to the predetermined destination when the voice subscriber line is not answered
within a period of time. The time period is configured by executing the timer ring-back command
and defaults to 60 seconds.
• Call forwarding unavailable—With this feature enabled on a voice subscriber line, an incoming
call will be forwarded to the predetermined destination when the voice subscriber line is shut down
by executing the shutdown command.