E1/T1 PCI card installation guide
6
1.3 Telephone
Network
Attachment
The E1/T1 PCI card with a revision 1.5 E1 PM1/2/4 Line Interface Module fitted, attaches to the
2Mbit digital system or Primary Rate (2.048 Mbit/s) Integrated Services Digital Network (ISDN).
Network attachment is via a service provision often used to connect digital PBXs to the
telephone network (NT1). It is available with 1, 2 or 4 primary rate ISDN ports and so may make
or receive 30, 60 or 120 separate calls at a time.
The E1/T1 PCI card with a revision 1.5 T1 PM1/2/4 Line Interface Module fitted, attaches to the
1.544Mbit digital system via a Channel Service Unit (FCC, IC or UL Listed CSU). It is available
with 1, 2 or 4 primary rate T1 ports and so may take or receive up to 23, 46 or 92 separate calls
at a time.
The E1/T1PCI card with a revision 2
PM 1/2/4 line interface module fitted, attaches to either an
E1 (2Mbit) or T1 (1.544Mbit) digital system as detailed above. It is available with 1, 2 or 4
primary rate ports and subject to each port configuration, may make or receive between 23 and
120 separate calls at a time. Each individual ports driver is software configurable for either T1 or
E1 (75 or 120 Ohms).
CAUTION
When making a network connection, to reduce the risk of fire, only telecommunications line cord of 26 AWG or larger may be used.
Please refer to the
Country Specific Information
appendices for more details of the various international
connections.
1.4 Call
Control
Processors on the PM Line Interface Module daughter-card (one processor per E1/T1 port)
control all of the call signalling (set-up, acceptance, clearing, etc.) in response to commands
from an application program running on the host computer.
The call control interface to the PM Line Interface Module is at a low level (in signalling terms),
and this provides maximum information and control over the various stages of call progress. This
interface is accessed via a device driver that has been prepared for the operating system in use.
The PM Line Interface Module processor checks each outgoing message provided by the
application program for syntax, validity of content and context. If errors are found, the call is
automatically cleared. The software on the PM Line Interface Module therefore forms an
effective barrier between the application program and the telephone network, and protects the
network from incorrect call signalling.
Several elements of call signalling related information are available to the application program,
although in some cases this depends upon provision by the Public Switched Telephone Network
(PSTN) of this information along with each call. One such information element is the number
used by the caller on calling into the card, (the DDI number); this is only available when the
service obtained from the PSTN is of the appropriate type. Another such information element,
which may be available, according to the protocol and PSTN, is Calling Line Identity (CLI),
which on incoming calls makes the telephone number of the calling party available to the
application program.
Full details on the control of calls using the E1/T1 PCI card are available in a separate
publication, the
Aculab Call Control API Guide
. This guide can be downloaded from
the
company web site at
www.aculab.com
1.5
Speech and Data Paths
Speech and data associated with telephone calls are not terminated on the card, but are always
switched without modification to other cards, or on-board modules, for processing. The card
maintains bit integrity within timeslots between ports on the card. The card is configured to
operate with one of these expansion bus types; simultaneous use of multiple expansion bus types
is not currently supported.