I don't want the Loopback Device to answer every call, how do I ensure it only answers specific test calls?
A software CD ROM is provided with each Loopback Device which should be installed on to a suitable PC host. When installed, connect the device using the serial lead supplied and run the Loopback software to view the trigger options available. A user friendly GUI allows you to select either answer all calls, calls from a particular number (CLI), calls using a particular subaddress or calls using a particular MSN. It is also possible to select a delay before connection so that other terminals may answer the incoming call before the Loopback device, if required.

Which ISDN protocol does the Loopback Device support?
The Loopback Device supports ETSI Euro-ISDN (TBR003).

How do I configure the Loopback device to answer specific calls?
The configuration software supplied with the Loopback Device is very simple to operate and clearly shows the range of call trigger options available. A PC host is only required to alter the configuration which will remain in the device until a new one is saved.

What can I use to call the Loopback Device?
If the Loopback device is set to answer 'any' call (default) then it may be called from any analogue/ISDN/mobile telephone/call making device. Alternatively you may set a trigger to specify a particular calling number, call type or supplementary service in which case the device will only answer calls from the chosen source. In order to check the quality and availability of the ISDN line it is better to call from a hand held bit error rate tester so that a test can be run between the local site and the remote site. Another good option is to call using an ISDN video conferencing terminal which, when the call connects at the Loopback device, will allow you to see your own image on the screen to give a clear indication of the quality that you can expect between the two sites. Traffic generation equipment is often used to call Loopback devices at many different remote sites so that network quality measurements may be taken overnight.

Are other versions of the Loopback Device available?
There are various special versions of the Loopback device available please call us to discuss your application.

How is the Loopback Device powered?
The Loopback Device is a very efficient device that may be powered by the ISDN line to which it is connected (in Normal or Restricted mode). For lines which do not provide Phantom Power (such as the UK's BT Home Highway service) a low cost power adaptor is available as an option. If the power adaptor is used, power will not be drawn from the ISDN line.

What do the PS1 Normal and PS1 Restricted LED's on the Loopback Device tell me?
PS1 (power source 1) Normal in the ETSI Euro-ISDN specification states that a nominal supply of 40V DC up to 1W of power will be provided by the network termination (NT1). The power under these normal arrangements will probably be derived at the NT1 from a local mains source. Under mains failure conditions, the power will be limited to 420mW (Restricted Mode) and to indicate this state to the terminals, the polarity will be reversed. Please note that some network providers will always remain in Restricted Mode and some do not provide any power. Each of these power states can be verified by plugging in the Loopback device.

How do I know whether I need the optional power adapter?
Most ISDN lines provide Phantom Power because in a situation where local mains Electricity has failed, the power on the ISDN line should ensure that an ISDN telephone plugged in to the line will still operate to provide a basic Emergency service. When you plug the Loopback device in to the line it will provide (PS1) LED indication of Normal or Restricted power. If neither of these PS1 LED's illuminates, power is not available on the line and you will require the optional power adapter.