Compaq Armada 7400 Reference Manual page 172

Difficulties may occasionally be experienced from other apparatus
connected to the BT PSTN via the Compaq Armada 7000 Series II
modem apparatus. Such difficulties may include the following:
Difficulty in making calls
Problems in telephone conversion being experienced by both
parties to the call
If the above mentioned difficulties are experienced, please contact
your product supplier or your authorized Compaq reseller in the
United Kingdom.
This device is intended for auto-answering of incoming calls.
Under normal conditions callers will be accustomed to calls being
answered within 10 seconds, and a majority of callers will
abandon calls that are not answered within 45 seconds.
There are several options available for auto-answering operation.
The default setting is for two incoming rings. This is the
recommended setting for normal operation by most computer
users.
When entering telephone numbers, ensure that the number that
appears on the screen is correct before beginning to dial.
The following lists the modem approval statements:
This (Series 577) modem is approved as a host independent
product. This approval number is a general approval number.
APPROVED for connection to the telecommunications
systems specified in the instructions for use, subject to the
conditions set out in them.
DGT No. NS/5141/3/V/607050.