Configure the ISDN BRI Line Interface
80 Perle 833IS User Guide
Configure the ISDN BRI Line Interface
Overview An ISDN, BRI line is a digital transmission link with a capacity of 160Kbps. This
bandwidth is split up into 2*64Kbps “B” channels which carry user data and a
16Kbps “D” channel used to transfer control information for such tasks as setting up
and tearing down calls. From the user perspective, each “B” channel looks like an
individual phone line with its own phone number. Each “B” channel can carry either
pure digital data or digitized analog data. If the call originates from an ISDN type of
a device (eg. a Terminal Adapter), the B channel will contain pure digital data. If the
call originates from an analog device (eg. a modem), the B channel will contain a
digital representation of the analog data. The latter type of traffic will require a
digital modem to handle the data.
The ISDN interface is available in two types: A U interface and an S/T interface. To
find out which type of interface you have follow this procedure.
■Look at the card name. This can be found on the back of the card or see “Feature
Cards” on page 25.
■The first 3 letters should be BRI
■The fourth letter is either a U or an S.
If the fourth letter of the card name is a U, this is a U interface ISDN card. If it is an
S, this is an S/T interface ISDN card.
The type of information which will be required for the line interface depends on the
Network provider you have selected and the type of ISDN interface they provide.
Different Telephone companies use different switches to handle the ISDN BRI lines
which in turn require different parameters to be set up. In general, your ISDN
provider should provide you with the information you will need to correctly
configure the line interface. Some of the fields on the screen may not be required for
your specific environment.
If you are unsure about any of the fields, ask your ISDN provider for the correct
value for the field in question. If your ISDN provided has no information on a
specific item, leave the field blank.
The 833IS needs to synchronize with the ISDN line. All BRI lines connected to an
833IS must be driven from the same clock. In most applications, the 833IS is
connected to the telco network, and all clocks from the telco are guaranteed to be
derived from the same clock. If you are connecting the 833IS to a PBX, ensure that
the PBX is providing the line clock.