CorNet Virtual Networking (CorNet-VN) is a patented signaling protocol whereby the networking capabilities of CorNet-N are supported over a public switched telephone network (PSTN) connection. This is done by passing the proprietary signaling elements of CorNet-N through the PSTN using the user-to-user signaling (UUS) capabilities of the public network carrier.

CorNet-VN is offered to U.S. customers as an alternative to conventional CorNet-N or CorNet-NQ trunks that require dedicated T1 facilities. CorNet-VN is not intended to replace CorNet-N or CorNet-NQ trunks, but rather augment them with a solution that is more cost effective in certain customer environments. The typical situation where CorNet-VN is more cost effective than CorNet-N/NQ trunks is for inter-connecting distant locations that have low traffic volume where dedicated or leased-line facilities would be expensive and under utilized. CorNet-VN shall be supported across AT&T and Worldcom (formerly MCI) public telephone networks.

The above figure illustrates a typical CorNet-VN network whereby CorNet-VN is used for long-haul non-IP connectivity through the PSTN. CorNet-N is used for lang-haul non-IP connectivity between OpenScape 4000/HiPath 4000 switches. CorNet-NQ is used for short-haul non-IP connectivity between OpenScape 4000/HiPath 4000 switches. The figure shows a mix of switch types that are CorNet-VN capable as well as a non-CorNet-VN-capable switch that is connected to the PSTN using conventional ISDN-PRI.