Virtual PBX systems, cloud PBX systems or hosted PBX systems are business telephone systems that deliver PBX functionality as a service, available over the public switched telephone network (PSTN) or the Internet. Hosted PBXs are typically provided by a telephone company or service provider, using equipment located in the premises of a telephone exchange or the provider's data center. This means the customer does not need to buy or install PBX equipment. Generally the service is provided by a lease agreement and the provider can, in some configurations, use the same switching equipment to service multiple hosted PBX customers.
See Melrose Labs Voice Gateway/CloudPBX
Melrose Labs: 我们的使命是为企业，短信聚合器和消息传递提供商提供跨移动，固定电话和互联网的云通信中的关键服务。这些服务使组织能够在向客户提供服务，可靠性，对服务的洞察力以及提高的运营效率方面取得飞跃。