Facsimile gateways

Facsimile switches

Managed network use

G3 networks, switches, gateways and PC fax.

Translate in written form points

PART 4 (60.6 – 60.7)

The success of G3 facsimile has encouraged the provision of addi­tional equipment/facilities to enhance operation and provide cost savings. The communication interfaces are based on T.4 and T.30 recommendations and follow standard facsimile protocols. Where these units are provided by suppliers different from the machine suppliers, the NSF proprietary operation is often precluded. This can result in a loss of facilities and an increase in transmission time. It may also mean that because of simple interfaces used, MR, ECM, 14.4kbit/s CCITT options are not implemented and transmission efficiency is limited.

By the provision of store and forward units with multiline PSTN access, a network operator or value added supplier can relieve the user of major distribution tasks and free the user's machine for other work. With multiline access it is realistic to consider a regular broadcast transmission to 10000 recipients from a single originator transmission to the store. To some extent the network operator can schedule the traffic to suit network loading and therefore offer practical tariffs which could compensate for the delay in delivery and the subsequent confirmation report necessary.

The requirements of some major users include facsimile traffic control and costing, archival recording of all transferred facsimile messages and controlled distribution of centrally received incoming messages. By routing the facsimile traffic through an intelligent central switch, possibly associated with the company PBX, the required monitoring and control functions can be provided with cost and traffic reporting developed to suit the individual needs of the user. (Figure 60.8.)

One main area of concern for facsimile users is the onward distribution of documents received at central machines maybe lo­cated in the mail room. Onward distribution is often delayed waiting for the next mail round, and onward transmission by facsimile to the department in question is sometimes not felt desirable.

One solution being considered is that the facsimile switch can have a soft copy display of the facsimile message on a VDU. An operator would then display and readdress the document for onward transmission from memory. Clearly, for efficient operations, a suit­able compromise must be made between the switch capital cost and the time required by the operator, to re-route the document.

The transmission of facsimile documents and of electronic mail or computer generated text are usually kept separate. However the wide population of G3 machines has encouraged users on electronic mail or local area networks to request interoperation. This is usually achieved by fitting a gateway on the computer network to convert the information to the T.4 and T.30 facsimile format for onward transmission.

The problem is for incoming documents in the facsimile domain. These are virtually impossible to convert to the text environment and require onward transmission in a graphics mode with the high bandwidth and large storage capacity associated with raw image data. These facsimile documents are most conveniently printed out on a local facsimile unit and kept separate from the data system.

Дата добавления: 2015-03-31