Description
Tahoe 681 is a 2-wire G.shdsl+ modem with an Ethernet port. Over a single copper pair it carries symmetric data at up to 5.7 Mbps over a distance of several kilometres, depending on line quality and the configured data rate.
In addition to the modulations defined in the G.shdsl standard, it supports TCPAM-32, which on the same line gives longer reach and a higher data rate than the standard TCPAM-16.
Features
The modem has a built-in TCP/IP router with a firewall, a DHCP/BOOTP server and VLAN support. It can also work as a transparent bridge, managed or unmanaged.
Configuration is done from the built-in LCD display and keypad, via the serial console or via telnet. The full list of features is in the Technical data tab.
Several hardware and software watchdogs monitor the device, from basic processor functions to network communication. The metal enclosure is designed for years of continuous operation.
Technical data
| Throughput | up to 5.7 Mbps | |
|---|---|---|
| Standards | G.shdsl, conforms to ITU G.991.2 | |
| Interface | Ethernet 10/100 Base-T | |
| Modulation | TCPAM-32, up to 30% higher reach in comparison to HDSL | |
| Features |
| |
| Processor | Freescale PowerPC 50MHz | |
| Memory | 4MB SDRAM | |
| Performance | up to 8,200 packets per second | |
| Network protocols | TCP, IP, UDP, ICMP, TFTP, SNMP, DHCP, BOOTP, PPP, Frame Relay, HDLC, Cisco® HDLC, IEEE 802.1q | |
| WAN encapsulation | ATM AAL5 | |
| Dimensions | 200 mm (width) x 130 mm (depth) x 45 mm (height) | |
| Power supply | 15-30V, 260-130 mA, 3.5W (110-230V/50-60Hz power supply included) | |
Reach
Values below were measured on a test line of 0.5mm wire diameter. They depend on an actual line and thus are not guaranteed. They may be different - higher or lower - in an individual case.
| Throughput | Reach on 2 wires |
|---|---|
| 5696 kbps | 2500 m |
| 3072 kbps | 3500 m |
| 2048 kbps | 3900 m |
| 1024 kbps | 5000 m |



