[USR-TC] Strange things with ARC/DSP showing ISDN conns.

My DSPs and ARCs are showing strange IMPOSSIBLE!!! things: sh stat call_stat: Number of ISDN Calls: 22 I know that here, in this area, nobody has ISDN, but PSTN has this option. I have configured DSPs only for analog, not digital. What are those "Number of ISDN Calls"? Is SHOW STATISTICS CALL_STATISTICS correct? What do I have to configure on DSPs/ARCs?