PortaNet User Manual
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How does the PortaNet work?
Given the different nature of the two communication standards that the PortaNet
supports, the unit has to adopt different configurations while adapting to the
characteristics of each network. What’s more, in certain situations, PortaNet is
capable of dealing with two independent communications at the same time. This
can be a cause of confusion for the user, who may be expecting a certain
behaviour or action from the unit but observes another. This chapter is
therefore a practical guide to help in understanding just how the PortaNet unit
works under different configurations, especially the more unusual ones.
IX.1
Selecting the communications interface
Firstly, when we refer to the ‘communications interface’ we are always referring
to the communications port that is used for the transmission of ‘audio data’. The
NET option in the main menu is for setting this up. There are three settings
available with the PortaNet:
a.
PortaNet operating as “IP CODEC”: The PortaNet will be configured to
establish communications via the Ethernet port using the IP protocol.
b.
PortaNet operating as “ISDN CODEC”: The PortaNet will be configured
to establish communications via a basic access ISDN connection. The
PortaNet has a multi-protocol ISDN terminal socket ready for
connection to a basic rate 2B+D interface.
The Ethernet interface is always available for remote control of the unit, even
if it is configured to operate as an ISDN codec.
You should first select the network type - i.e. the communications interface - to
be used for audio data transmission and reception. The menu will only show the
configuration options relevant to the network type selected. Of course, there are
a number of general parameters that will be the same across all network types
and so will not be affected when the network type is changed.
IX.2
Configuration parameters that are dependant on the
network type selected
There are two fundamental reasons for which the user must change the PortaNet
configuration parameters when a new communications interface is selected:
