Connections Through Public Or Private Data Networks; File Transfers; Video Teleconferencing; Figure 9-3. A Possible File-Transfer Configuration - AT&T DEFINITY 2500 series Network Manual

9-6
DATA 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 9-3 shows a possible configuration for the transfer of data from one communications system site to
another. Any AT&T nodal service (for example, the
Spectrum,
ACCUNET ACCUNET
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.
F
HOST
MPDM
E
IBM
P

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
Digital Network. The recommended configuration for this type of connection is shown in figure 9-4.
Packet Service, and so forth) can be used in the transfer. To use the packet
DS1
S75/S85/
G1/G2
Figure 9-3. A Possible File-Transfer Configuration
ACCUNET
Switched Digital Service,
ACCUNET
DS1
DATA NETWORK
Switched Digital Service or the Software-Defined
ACCUNET
S75/S85/
MPDM
G1/G2
. . . . . .
OR
IBM SYS.
CLUSTER
36/38
CONTROLLER
43XX;
NON-IBM
T1.5,