Ip Gateway Using Serial Link - Dialogic DMG1000 User Manual

Overview
1.1.1.1 Serial Protocol Support in Phone Emulating Mode
By emulating telephone sets to the switch, the Media Gateway provides call party information over
the IP network. However, the amount of call party information that the Media Gateway can provide
is limited to the amount of data that the switch provides its station sets. Some proprietary switches
provide full call party information across the station set interfaces while others provide little or no
call party information across the station set interface. The PBX switches that provide little or no
call party information typically will provide full call party information across a separate serial
interface connection.
For this reason, the Media Gateway supports a serial link interface to the switch or PSTN, and
supports several serial protocols. Figure 3 shows how the Media Gateway connects to a switch or
PSTN that uses a serial link to provide call party information. Using this serial link, the Media
Gateway is able to provide full call party information on a PBX switch or PSTN that provides little
or no call party information via their station set interfaces.
Figure 3. IP Gateway Using Serial Link
When a call arrives at a telephony port on the Media Gateway, the switch or PSTN will send a data
packet across the serial link containing the call party information associated with the call. If
configured to use the serial interface, the Media Gateway will use the data in the serial packet as the
call party information when the call notification is sent across the IP network to the VoIP terminal
device that the call is intended for - superseding any call information that may have arrived across
the station set interface. Finally, the serial protocols also support the message waiting indication
(MWI) feature that allows the Media Gateway to control message indications on telephone sets
connected to the switch or PSTN.
24
PSTN
Phone Lines
1 - 4 T1/E1
Digital PBX
Note: The T1/E1 Models must only be connected to
®
Dialogic 1000 and 2000 Media Gateway Series User's Guide — September 2007
Note: Only the Analog and T1/E1 Models
can connect to the PSTN.
Serial Link
IP Media Gateway
(Phone Emulating)
1 - 8
or
Trunks
the PSTN through an NTU, CSU or other
device that provides line isolation.
VoIP
Terminal
Device
VoIP
Terminal
Device
LAN
Dialogic Corporation