Net-2000™ Voice Codec Unit
User’s Manual
Page 18
Section 3 – Net-2000™ VCU Control
DVSI Confidential Proprietary
RS-422 Synchronous
Figure 12 Channel Source Selections
Ethernet Loopback (Local)
In loopback communications mode the Net-2000™ VCU will encode speech received on the selected
voice source input (Handset 4-Wire or 2-Wire) and play out the encoded/decoded speech on the
handset and Line-Out interface. This channel selection is useful when encoding / decoding recorded
voice samples as a quick analysis of the selected vocoder.
When Loopback communications mode is selected the Net-2000™ VCU sends data over the internal
loopback Ethernet address of 127.0.0.1 Loopback can also be accessed by entering in the IP or host
name of the Net-2000™ VCU in the Target IP address box.
Ethernet Channel Source Interfaces
Selecting Ethernet as the Channel source allows the Net-2000™ VCU to communicate to another
device across an Ethernet network.
When running in VOIP Mode the VCU encodes a frame of speech from the specified voice interface
and sends the encoded data over the Ethernet channel interface to the target IP address. At the
same time the VCU expects to receive packets from the Ethernet communications channel interface
that contains a decode command and encoded data.
RS-422 Asynchronous and RS-422 Synchronous Interfaces
When either of the RS-422 interfaces are selected the Net-2000™ VCU encodes speech received on
the selected voice source input (Handset 4-Wire or 2-Wire) sends out the encoded speech data over
the selected RS-422 interface. This channel selection is useful when encoding / decoding voice
between two Net-2000™ VCU that are not located far apart. Two Net-2000™ VCU units can be
easily connected together using the Asynchronous connection and a crossover CAT5 cable. See
Section 5 for connector pinout details.
In VOIP mode the Net-2000™ VCU also transmits packets over the asynchronous RS-422 interface
when the Ethernet interface is the channel source. This is a useful method to monitor the Net-2000™
VCU channel data.
NOTE: DO NOT attempt to connect or use the RS-422 Asynchronous and RS-422
Synchronous ports at the same time.
Target IP Address
The Net-2000™ VCU can communication with another NET-2000™. To communicate (encode and
decode to / from) to another Net-2000™ VCU via Ethernet first select Ethernet as the Channel
source. Next enter the IP address or host name of the remote unit you are connecting to, in the
Target IP address box located under the Channel source pull down menu.
Port Number
The network settings page allows the operator to change the network port number for the
communication channel. The default port number is Port 4000. If a different port number is required
enter in the desired port number and select the configure button. Valid port numbers are greater than
1024 and less than 65535. Port numbers 4001, 4002 and 4003 are reserved by the Net-2000™ VCU
and must not be used.