Internal Calls - ADTRAN Express 5210 User Manual

Chapter 5. Applications
are trying to reach. The host looks up the extension in the
extension/DLCI table and routes the call appropriately. If the
extension does not exist, the Express 5210 generates a trunk busy
signal back into the PBX. Otherwise, the host routes the call to the
appropriate port. When the remote party answers the call, the data
link is established and the call remains up until the remote
Express 5210 hangs up or until a loss of line current is detected on
the FXO port.

Internal Calls

When the telephone set on a remote Express 5210 is taken off-hook,
the remote Express 5210 generates a dial tone and waits for the
extension to be entered. Once the extension is entered, the remote
Express 5210 transmits this information to the host Express 5210,
where it is compared to extension information in the extension/
DLCI table. If the extension is found in the extension/DLCI table,
the call is routed to the appropriate extension via the host unit.
When the called unit goes off-hook, the data link is established and
remains up until one of the two extensions terminates the call.
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