AT&T 7400 series, 7500 series Connections Through Public or Private Data Networks, File Transfers

9-6DATA COMMUNICATIONS CONFIGURATIONS

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CONNECTIONS THROUGH PUBLIC OR PRIVATE DATA NETWORKS

You can connect your local communications systems with each other through DS1 facilities over public or private data networks for file transfers, video teleconferencing, image processing, and FAX transmittal. Connecting the sites through a DS1 facility allows you to take full advantage of the DS1 capacity — for multiple data applications, or for both voice and data.

File Transfers

Figure 9-3shows a possible configuration for the transfer of data from one communications system site to another. Any AT&T nodal service (for example, the ACCUNET Switched Digital Service, ACCUNET T1.5, ACCUNET Spectrum, ACCUNET Packet Service, and so forth) can be used in the transfer. To use the packet network, however, the data must be processed by an X.25 packet assembler/disassembler (see chapter 8) immediately before and after it is processed through the network. File transfer applications include bulk data transfer, database update transactions, and electronic messaging.

HOST	F	MPDM	S75/S85/	DS1	DS1	S75/S85/	MPDM
				DATA NETWORK
IBM	E		G1/G2			G1/G2
	P
						. . . OR . . .
						CLUSTER	IBM SYS.
							36/38
						CONTROLLER
							43XX;
							NON-IBM
		Figure 9-3.A Possible File-Transfer Configuration

Video Teleconferencing

Slow-scan video teleconferencing between communications system sites is possible via a single or double 56-kbps DS1 connection. For example, PICTURETEL has made it possible to transmit full-motion video over the SW56 and SW64 capabilities of the ACCUNET Switched Digital Service or the Software-Defined Digital Network. The recommended configuration for this type of connection is shown in figure 9-4.