Which to Use: ISDN vs. IP?

All sites using the regional Videoconferencing Service can connect via both ISDN or IP, depending on a number of factors, as described below:

1.	Remote Site Capability: The remote site you are looking to connect to may only be capable of connecting via ISDN or IP - the site may not have both.
2.	Video/Audio Quality: Similar to a regular voice phone call, ISDN provides dedicated bandwidth for smooth audio and video. On the other hand, IP videoconferencing shares or competes for bandwidth with other data on the public Internet (e-mail, web browsing, etc,). This may cause audio clipping, video freezing, or transmisssion delays, which can become problematic in a real-time videoconference. IP video traffic can be prioritized on closed networks like the regional WAN to minimize outside data interference.
3.	Reliability: For reliability, picture the difference between ISDN and IP as the difference between making a phone call and accessing a web site. It is rare that you will pick up the phone and be unable to dial someone for a voice conversation. More often, various network issues can restrict you from accessing a web site (website is down, your data network is down, too much traffic on the network, etc.). ISDN and IP video work the same way: ISDN provides a reliable dedicated connection, although IP has gained rapidly in the last few years.
4.	Usage Cost: Because ISDN uses the public phone network, it works similarly to your office or home phone. The phone company charges for each call made. These calls can become quite expensive, depending on where you are calling and at what speed you are calling. IP videoconferencing is similar to e-mail. Because IP uses the data network, there are no usage costs.
5.	Convenience: If you are connecting to only one remote site, IP videoconferencing allows you to "dial-up" directly to the remote site using the site's Internet address. An intermediary is not required for a point-to-point IP videoconference. Because ISDN requires special phone lines, sites connecting via ISDN will need to schedule the conference with a gateway to convert the signal to ISDN. Depending on your location, there are two ISDN gateways available in this region.