/usr/share/isdn/rate-default.dat is in isdnlog-data 1:3.25+dfsg1-3.3~deb7u1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 | V:0.01-default [2001/10/10]
U:%.3f UNITS
P:10 .
B:1234
D:x
# 1 currency unit per minute
Z:1 .
A:*
T:*/*=1.00/60
|