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VoIP subscriber gateways
11
2.4
Architecture and the device operation principle
TAU-8.IP/TAU-8.IP-W subscriber terminal consist of the following subsystem:
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Controller includes:
Mindspeed digital signal processor;
flash memory – 16MВ;
SDRAM Operating storage – 256МВ;
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SLIC Subscriber complex (8×FXS ports);
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Ethernet-module RJ-45 10/100/1000BASE-T WAN;
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Wi-Fi adapter (only for TAU-8.IP-W);
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USB-module.
Fig. 2 shows the device architecture diagram.
Fig. 2 – TAU-8.IP architecture diagram
TAU-8.IP architecture diagram differs by absence of Wi-Fi module.
Linux operating system controls the device operation. Basic control functions are performed by
Mindspeed digital signal processor which enables IP-packets routing, IP-telephony operation, group traffic
proxying and etc.
The device can be divided into 4 blocks by functionality:
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Device network features block;
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VoIP block;
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Processing block of multicast traffic;
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Control block (Linux operation system).
Device network features block
provides passing and switching IP-packets in accordance with the device
routing table and can process both untagged and tagged packets depending on network interface settings. The
block supports DHCP, PPPoE and PPTP protocols.
VoIP block
provides the device operation via SIP protocol to transmit voice signal through packet-
switched network. Subscriber’s voice signal is transmitted to the SLIC subscriber line module to be digitized.