COMSPHERE 3600 Series Data Service Units
1-2 July 1999 3610-A2-GB91-90
The rear connector plate shipped with the Modular
3611 DSU contains two 25-pin DTE connectors, a
25-pin EIA-232-D/V.24 connector and a 25-pin
V.35 connector. It is shipped with a modular DSU
V.35 adapter (feature number 3000-F1-510) for
when the V.35 interface is needed (V.35 is
recommended for speeds of 19.2 kbps or greater).
The adapter provides an interface between the
DSU’s 25-pin D-type connector and the DTE
cable’s V.35 connector.
The following options are available for the 3600 Series
DSUs:
• V.32 DBM (dial backup module). The V.32 DBM
option ensures continuity of service through the
public switched telephone network (PSTN) in case
of failure of the DDS connection.
• Switched 56 DBMs. The 4-wire Switched 56 DBM
and 2-wire Switched 56 DBM options ensure
continuity of service through the switched 56 kbps
2-wire or 4-wire network in case of failure of the
DDS connection.
• TDM (time division multiplexer). The TDM
option, an additional circuit card, supports time
division multiplexing and digital sharing for up to
six ports. It can serve as a digital bridge for
multipoint dial backup and multipoint local area
data set (LADS) operation.
• MCMP (multichannel multipoint). The MCMP
option provides multipoint TDM capability. The
MCMP capability allows up to six independent
application programs to share one 56 kbps
multipoint circuit. Channel speeds can range from
1.2 to 48 kilobits per second (kbps).
• SNA Diagnostic Interface. The SNA Diagnostic
Interface option supports the Link Problem
Determination Aid, Version 2 (LPDA-2) protocol
and is installed on the DSU circuit card. This option
supports DSU management from IBM’s NetViewt
host-based network management system (NMS), as
well as management from a Paradyne NMS, the
DSU’s diagnostic control panel (DCP), or all three.
This option also supports the DBM, TDM, and
MCMP features.
Feature Overview
The 3600 Series DSU, without any options, offers the
following features:
• Multispeed operation. A 3600 Series DSU
operates on the DATAPHONEr Digital Service
network, or equivalent digital data service (DDS)
network, at data rates of 2.4, 4.8, 9.6, 19.2, 38.4,
and 56 kbps full-duplex. The 3600 Series DSU is
also compatible with the new ACCUNETr
Spectrum of Digital Services network (ASDS).
The 3600 Series DSUs have two DTE interfaces: an
EIA-232-D/ITU-T V.24 interface for operation at
rates up to and including 19.2 kbps and a
ITU-T V.35 interface for rates up to 64 kbps. The
user selects which interface is active.
• Clear Channel capability. A 3600 Series DSU
supports 64 kbps Clear Channel operation on a
72 kbps local loop.
• LADS operation. A 3600 Series DSU can operate
as a local area data set (LADS) (sometimes called a
limited-distance modem, or LDM) at 2.4, 4.8, 9.6,
19.2, 38.4, 56, or 64 kbps full-duplex.
• Single-Port Async/Sync. Single-port
asynchronous-to-synchronous operation provides
asynchronous-to-synchronous data conversion for
DTE ports (both EIA-232 and V.35); that is, the
DSU can send asynchronous data over a
synchronous network.
• Nondisruptive diagnostics. In a nondisruptive
diagnostic network, diagnostic data is transmitted
without interruption to user-transmitted data.
• Rate Adaption. This feature enables the DSU to
support a low-speed application on a high-speed
DDS circuit. When additional bandwidth is
required, the customer can reconfigure the DSU
port to operate at a higher speed without supplying
a new DDS circuit. Rate adaption is supported for
both point-to-point and multipoint configurations.
For further information, see the section entitled
Rate Adaption later in this chapter.
• NMS control. The Models 3610 and 3611 DSUs
can be controlled by the following Paradyne
Network Management Systems (NMS):
COMSPHERE
6700 or 6800 Series NMS;
DATAPHONE II System Controller, Diagnostic
Console, or Network Controller; and ANALYSISt
6510 NMS. (Note that the Model 3610 DSU
requires a 3600 Hubbing Device for connection to
an NMS.)