The invention relates to a switchboard being consists of a mesh type net connecting module which is used for realizing the middle and small capacity switchboard or a centralized net connecting module which realizes the high capacity switchboard with the help of adapting circuit. The character permits the small capacity switchboard being deployed. As no centralized components are existed, the cost is economical. When the telephone traffic of consumer is rapidly increased, the invention can be converted into a high capacity switchboard; the adapting circuit consists of a speech signals parallel installed to tandem converting unit (IFT), the circuit unit comprises a signal processing unit which is transferred signals between each converting unit in the switchboard and a speech signals tandem to parallel installed converting unit (IFR). |