Question: PictureTel system is strapping an ISDN (Integrated Services Digital Network) board to ATM (Asynchronous Transfer Mode) board to trick it into thinking its on ISDN when it's really on ATM. Therefore, how will Apple be supporting ATM and when? Or, fast Ethernet? (Is this ISO-Ethernet?)
Answer: Apple has made no announcements about supporting ATM or fast Ethernet at this point, primarily because of the component architecture of QuickTime Conferencing (QTC). QTC has a separate transport layer that can be written for specific protocols you want QTC to use (ATM, Fast Ethernet, or ISO-Ethernet). Customers could write their own transport component for their needs. National Semiconductor announced plans to build a ISO-Ethernet card at the QuickTime Conferencing intro in February 1995, but you need to check with National Semiconductor concerning availability of this card.
Question: How can I interface Ethernet/T1 to ISDN for remote sites that do not have T1 access? In other words, if one user is on T1 can they connect to an ISDN user?
Answer: ISDN implements the ISDN-1 standard for a BRI (Basic Rate Interface) giving the user 2 B (56 or 64 kbps) and 1 D channels. T1 implements the ISDN-2 standard where the user has 23 B (56 or 64 kbps) and 1 D channel. If both the BRI and PRI use H.320, then they can use it. Otherwise they will likely use IP to communicate with each other.
Question: Does the H.320 take advantage of its hard compression over an existing Ethernet LAN or Fast Ethernet or ATM?
Answer: No, the H.320 hardware component is only used in an ISDN WAN connection. Once you switch the network type to AppleTalk or TCP/IP instead of ISDN, then you no longer interface with the H.320 board and cannot take advantage of the hardware H.320 compression. QTC does include a software H.261 compressor for the LAN video. H.261 is a subset of the H.320 standard, so in actuality some H.320 can occur, but the preferred compressor for a LAN connections is JPEG for IP and Apple Video Compressor for AppleTalk.
Question: For normal Internet access is additional software required? Is anything different required of the ISP (Internet Service Provider), or the Internet connection such as router, CSU/DSU?
Answer: The currently shipping QTC/ISDN Kit does not include software for an internet connection with an ISP. You can connect to an ISP with no additional hardware, you just need software.
Question: Is it possible to use either a point-to-point connection, or Apple Remote Access connection over an ISDN line with QuickTime Conferencing?
Answer: The current version of QuickTime Conferencing requires Ethernet or an installed H.320 ISDN card.
Article Change History:
11 Jun 1996 - Added last Q & A pair.