Words below consisting of uppercase letters like RATEFILE refer to the so named setting in the general isdnlog configuration file /etc/isdn/isdn.conf.
The rate-file contains one or more providers for a country. A provider covers an offer of a telephone company. Usually there are now many telephone companies in a country and most companies offer several different price lists.
A provider is identified by provider number and provider variant or sub number. The provider number, short pnum, is commonly used for all offers of one company. The provider variant, short var, is used to number these offers starting from 0. A specific provider is referenced as pnum,var or pnum_var depending on the context.
VBN contains the shared leading digits of the carrier selection prefixes. The entire prefix for a provider is specified in the rate-file by the B: tag. In Germany the carrier selection prefix begins with 010 followed by two or three digits which make the pnum ranging from 10 to 199. A mapping like this is not required but common.
The overall format of rate.conf is similar to the rate-file, lines starting with tags P:, X:, or Q: may occur in any order and quantity. (Of course, the resulting configuration should make sense.)
Mark the provider specified by pnum and var as booked or active. Only booked providers are taken into account when isdnlog computes the connection costs. Booking also tells isdnlog the provider variant to use if there are more than one.
Beside computation of real connections booking also splits the providers in two groups: the booked ones that are available at the specific subscriber line at the not booked ones that are less important for price comparison.
One provider in booked group is declared the default provider by setting PRESELECTED to its pnum. This provider is assumed to be used if a connection is made without a carrier selection prefix and no exceptions matching.
Connections to number will be assigned the booked provider with pnum as provider number regardless of a dialed provider selection prefix or the PRESELECTED setting. zone if present replaces the normal zone selection based on destination codes. Exceptions can also be given in the rate-file.
In rate.conf exceptions may become necessary if there different preselected providers for local and distance calls for example or if preselection does not apply generally, e.g. not for connections to special numbers.
At least for some countries there are universal rate-files distributed with isdnlog or provided elsewhere. In this case it is desirable to keep the rate-file unmodified so that updates require no further changes beyond installing the new rate-file. If a rate-file aims to cover the telephone market in an entire nation there will be always providers in it which are not available or not suitable for a specific installation. Such providers can be disabled by not booking them but they remain present and may be displayed as overall cheapest provider or the like.
Provider skipping completely ignores selected, so called skipped providers, from the rate-file. To be more precise, the effect of skipped provider could also be achieved by deleting its lines starting from its P: tag to the last line before the P: tag of the next provider from the rate-file.
Providers to skip can also be configured in the parameter file of isdnlog using the syntax described below in a line starting with skipProv= instead of Q:.
Skipping applies to all providers that are matched by a given range. If var is missing, all providers with pnum are skipped.
* matches all providers.
Booked providers are not skipped unless ! is given at end of the range or in front of the entire list where it applies to whole line.
The ~ can be given alternatively to !. Providers that match such a range are not skipped under any circumstances.
Space can occur anywhere in the line after Q:.
Q:*; 13,1~; 33-33,1~; 200-299!; 321-323!
This skips all not booked providers except 13_1, 33_0, and 33_1. Additionally all providers with a pnum between 200 and 299 or 321 and 323 are skipped.