known systems couple terminals via network - entities to an internet / intranet by , at said terminals , generating first codes for activating couplings from terminals via network - entities to said internet / intranet , and deactivate at least a part of said coupling by , at said terminals and / or at said network - entities , generating second codes , with said network - entities detecting said first and second codes . to introduce call - on - hold features and session - park features , systems according to the invention are provided with memories for storing coupling - information in relation to at least a part of said second codes , which memories generate said coupling - information in response to third codes . preferably , second codes will comprise subcodes indicating a deactivation - type , and in addition to said first and third codes , a fourth code is generated for security reasons .