Multi-Tech Systems MMV1600 System Features Voice/Fax, Networking, Dual Composite Links

1.5

System Features

1.5.1

Voice/Fax

With the addition of the voice/fax board into the MultiMux, you now can have voice and fax traffic along with your normal data communications on the same composite link. The two voice/fax channels provide all the necessary interfaces to access a private branch exchange (PBX, a small telephone switch) and all the services provided by the PBX. If a voice/fax channel is connected to the trunk side of the PBX, the remote location has free access to the local public switched telephone network (PSTN). With the addition of voice/fax, a free voice or fax communication can be established on top of the data communication over the same leased data communications network.

1.5.2 Networking

The networking feature adds the capability to design complex networks, it also meets a very basic need: saving phone line costs. Networking MultiMuxes allows the stringing of several MultiMux units together via dual composite links, using "pass-through" channel connections, to any MultiMux in a multinode network. The MultiMux checks for a code that will instruct it to receive the data or pass it on to the next node. Each composite link on a mux can establish rerouted connections with up to four other muxes in a network. Voice/fax channels must currently be connected point- to-point. However, voice/fax channel networking will be available as a future enhancement.

1.5.3

Dual Composite Links

The composite links of the MultiMux are capable of synchronous and full duplex communications over a digital data services (DDS) or dedicated network. The MultiMux has two composite links in which either integral 56K bps DSUs or equivalent external DSUs or synchronous modems can be connected. With dual composite links, another feature is added to the MultiMux in the way of networking. Networking MultiMuxes allows the stringing of several MultiMux units together via their composite links. This feature allows data to be routed over the composite links using pass-through channel connection to any MultiMux in the multinode network. The MultiMux checks for a code that will instruct it to receive the data or pass it on to the next node. Each composite link on a mux can establish rerouted connections with up to four other muxes in a network.

1.5.4

Dynamic Load Balance

A feature of MultiMux MMV1600/MMV3200 series multilink multiplexers is their ability to balance data flow between two composite links to utilize each to its maximum efficiency. To activate the feature you select D (for dynamic) as the composite link for each channel using the MLD command. At that point the MultiMux processor picks the least busy link for transmission. This feature can only be used in a point-to-point network using two MultiMuxes.

1.5.5

Channel Flexibility

The MultiMux permits a great deal of flexibility in configuring channel parameters. You can mix up channel options, including speed, word length, stop bits, parity, flow control, pacing methods, echo and pass-through. Channel control commands let you change single channels or all channels with a single command. By using the downline loading capability or the command modem, channels can be configured at the other end of the network.

1.5.6

Flow Control

Flow control regulates the volume of data entering the buffers. When a particular channel buffer is almost full, a flow control command is issued which stops further activity until the buffer is emptied. The most common flow control methods currently used are Xon/Xoff, RS232C signal control (using DTR or CTS) and ENQ/ACK. The MultiMux supports all three.