ZyXEL Communications VES-1000 Series, User Manual, Page: 121 / 227

VES-1000 Series Ethernet Switch
Port Setup 16-1
Chapter 16
Port Setup
Configure your VDSL and Ethernet ports in SMT menu 6.
16.1 Port Configuration
Port type (VDSL or Ethernet) is labeled under Type in menu 6. Enter the port index number to configure it.
This menu only shows the number of ports that are available on your particular VES. As an example, the VES-
1008A will show eight available ports and the VES-1012 will show twelve available ports.
16.1.1 Rate Adaption
You can configure the maximum rate of an individual VDSL port using the port setup SMT menus or web
configurator screens. However poor line quality (due to poor wiring, line noise, cross-talk or VDSL modem-to-
switch distance) may affect actual VDSL speeds attainable.
Rate adaptation is the ability of the device to adjust the configured transmission rate to the attainable transmission
rate automatically depending on your telephone line quality. The VDSL transmission rate then stays at the new rate
or adjusts if line quality improves or further deteriorates.
If rate adaption is disabled and attainable speeds cannot match configured speeds, then:
The VDSL link may go down or
Link communications may be sporadic due to line errors and consequent retransmissions
The VES determines line quality using the Signal-to-Noise Ratio (SNR). SNR is the ratio of the amplitude of the
actual signal to the amplitude of noise signals at a given point in time. A low SNR indicates poor line quality. When
the SNR (upstream or downstream) falls below a pre-determined threshold, the device then uses rate adaption.
Rate adaption applies to VDSL line connections only – not Ethernet connections.
See the section about VDSL mode for the range of speeds associated with each VDSL mode.
Enter 6 from the main menu to bring up Menu 6 – Ports Setup.