Tahoe 681 User Manual - 3.1
6
3.1.
Throughput setting
After pressing Enter the throughput may be set using up/down
buttons. In Tahoe 681 modem it may be chosen from 64-4864 kbps
range with 64 kbps step, while in Tahoe 682 - from 128-9728 kbps
range with 128 kbps step. In the latter case the actual throughput of
each line is half of the throughput set. Different rates for each line may
be set using the serial console or the telnet connection (see chapter 4).
After choosing the right speed and pressing Enter modem will
reset the connection and renegotiate it with new settings.
NOTE: The same throughput must be set on both modems.
3.2.
Modem type
After pressing Enter the modem type may be selected - either
Master (HTU-C) or Slave (HTU-R). After selecting the type and pressing
Enter again the connection will be reset and renegotiated with new
settings.
NOTE: Always one modem has to be set as a Master and the
other one as a Slave.
3.3.
Line coding
After pressing Enter the G.shdsl line coding (signal modulation)
may be chosen. The number (32 in the example above) means the
number of values encoded in one symbol (32 - 5 bits per symbol). The
higher this number is, the lower is the signal frequency, which gives
better immunity for signal attenuation and higher reach.
The second part - PAM or TCPAM - means either the Pulse
Amplitude Modulation or Trellis Coded Pulse Amplitude Modulation.
The latter is more efficient.
It is recommended to use the 32-TCPAM modulation, which
provides the best results. The remaining line codings are available to
provide compatibility with others’ manufacturers equipment. Moreover
32-TCPAM allows throughputs from 256 kbps to 4864 kbps per line,
while 16-TCPAM - from 64 kbps to 2304 kbps.
The “Auto” setting forces use of 32-TCPAM for speeds higher
than or equal to 256 kbps per line and 16-TCPAM for lower rates.
3.4.
Write configuration to EEPROM
Every change to the configuration will be lost after reboot or
power off unless the settings are written to the EEPROM. After reaching
this option just press Enter to save them.
3.5.
IP address and network mask on eth0 interface
As a factory default the Ethernet interface of the modem has the
IP address set to 10.0.0.1 and the network mask to 255.0.0.0. After
connecting to this address using telnet further configuration can be
done. The IP address may be changed, however, using the keyboard.
It’s useful when the IP address has been changed and then forgotten.
After pressing Enter, up and down buttons may be used to
change the first octet of the IP address:
Then after pressing Enter second, third and fourth octet may be
set. Afterwards the network mask may be changed. Up and down keys
lengthen or shorten it, respectively, by one bit:
7
Write config
to EEPROM
Line coding:
32-TCPAM
3.1
3.2
Modem type:
Master / HTU-C
Line rate:
9728 kb/s
IP address and
netmask on eth0
3.4
3.5
Set IP address:
10._._._
Set netmask:
255.0.0.0