Allnet ALL126AS3, Руководство пользователя

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ALL126AS3
USER’S MANUAL
217
that compares the level of a desired signal to the level of background noise. It is defined as the ratio
of signal power to the noise power. A ratio higher than 1:1 indicates more signal than noise. While
SNR is commonly quoted for electrical signals, it can be applied to any form of signal (such as
isotope levels in an ice core or biochemical signaling between cells). The ratio is usually measured
in decibels(dB)
The signal-to-noise ratio, the bandwidth, and the channel capacity of a communication channel are
connected by the Shannon
–Hartley theorem.
In digital communications, the SNR will probably cause a reduction in data speed because of
frequent errors that require the source (transmitting) computer or terminal to resend some packets of
data. SNR measures the quality of a transmission channel over a network channel. The greater the
ratio, the easier it is to identify and subsequently isolate and eliminate the source of noise.
6. Symptom:
Connected the CO Router with CPE Router within 300 meters RJ-11 phone cable got only less than
10 Mbit/s.
Cause:
Some testing program which is base on TCP/IP protocol such as FTP, Iperf, NetIQ, the bandwidth of
testing outcome will be limited by TCP window size.
Solution:
We recommend to test VDSL2 bandwidth best by Smartbit equipment, if you don't have Smartbit,
we recommend test that by IPERF program, and TCP window size must be settled max. 64k, the
parameter as iperf
–c server IP address –i 1 –t 50 –w 65535 for client side.
7. Question:
I just bought a ALLNET ALL126AS3 to replace my Quest DSL modem for my home. I was told any
VDSL2 modem would replace and give me higher communicati
on speeds. It doesn’t get me internet
when hooked up. All lights come on but no Link light. Is this the complete wrong application for this