Interfaces and Terminals as of I7.8
System Interfaces
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2. 1. 1
Basic Access Variants
A basic access is a digital network interface for connection to the public network or
to the private leased-line network. It can be set for the protocols DSS1 (public ISDN
network) and QSIG / PSS1 (private leased-line network).
A basic access has two 64 kbit/s user information channels and one 16 kbit/s con-
trol and signalling channel (2B+D).
One call or data connection can be set up on each bearer channel (B channel) si-
multaneously and independently of the other B channel.
A basic access can be barred for outgoing calls (
Outgoing Calls Barred
setting).
Basic accesses for connecting the PBX to the public network can be operated as
point-to-point and, with some network providers, also as point-to-multipoint (mul-
tiple subscriber number) access.
There are two types of basic access:
•
Basic Access T
•
Basic access S external
2. 1. 1. 1
Basic Access T
Basic access T is suitable for connection to both the public ISDN network and the
private-leased-line network.