10.55.4.1. No Answer 
- If one of the circuits used in the step by step dialing connection is capable of transmitting a NO answer signal, only dial pulsing or ISDN circuits are permitted for the entire step by step dialing link (problem of digit repetition in DTMF circuits). This is only necessary if a DTMF circuit is available in the link that is not capable of transmitting an ANSWER signal.
- In the digit range, the digit "# "cannot be used as the access code, since this digit is required for speedy through-connection once the last digit has been dialed (through-connection of the call only after step by step dialing timeout is thereby no longer valid -> immediate through-connection of the call). Once "#" has been dialed, it is not possible to dial further digits.