There are two types of VOIP Switches in VOIP business, As we have mentioned that two types of VOIP Switches are there one called SoftSwitch and the other is Hardware

Hardware VOIP Switch VOIP SoftSwitch

VOIP Softswitch is actually an API that is used to bridge a traditional PSTN and VOIP by linking PSTN to IP network and managing traffic that contains a mixture of voice fax data and video
As big companies in telecom sector making use of soft switch along with traditional (Hardward) HardSwitches. As there are always several option to integrate these with each other.

 VOIP and communication are becoming apart from each other after innovation in communication where many other application and solutions are available free of cost. 

 Whatsapp is one of the major splitter of VOIP business, many other messengers as well as free communication application available.  Due to such business loss the VOIP switch business is in a process of transformation in order to meet the todays communication needs.