Because a conference is interactive, any delay in the transmission of audio and video is quite noticeable. Given the requirement and demands of videoconferencing on the network, the availability of a QoS guarantee in the network transport is the single most compelling network characteristic when it comes to videoconferencing support. The ISDN network does offer QoS and is available globally. Connect charges vary, given the nature of the call, but they are modest enough that they can be covered handily in most organizations. The intranet will see full implementation of these protocols sooner.
Many organizations have complete control over their intranet infrastructure.
The result can set the network manager's hair on fire. Then the bottlenecks are likely to occur in the backbone or WAN links. WAN links are particularly susceptible, since the high cost of dedicated WAN connections often keeps transmission rates relatively low. Videoconferences are very likely to occur across WAN links since co-located workers are more likely to meet in a conference room or at the coffee pot. One serious limitation of enterprise network packet-based solutions is an inability to conference with colleagues and customers outside the enterprise.