Chapter 1 - Introduction HCD-E1
Installation & Operation Manual
1-4 Physical Description 01/01/01 08:07
To expedite the routing, HCD-E1 supports two “bundle” routing modes,
called “sequential bundle” and “alternate bundle” modes. In the sequential
mode, one “bundle” (group of consecutive time slots, identified by the
number of the starting time slot and the total number of time slots) can be
routed to the corresponding main link time slots, where they are inserted in
the main link frame sequentially, in consecutive time slots (1, 2, 3, 4, 5, etc).
In the alternate mode, the time slots are inserted in the following way: 1, 3,
5, 7, etc.
For data channels and the sublink, the user can either individually select the
main link time slots in which the user's data is to be inserted, or can use one
of the “bundle” routing modes. Time slots assigned to data channels are
always defined as data time slots. A sublink time slot is always routed to the
main link time slot with the same number.
Priority Bumping
HCD-E1 will continue working (at a half of its baud rate) even if one of its
HDSL lines is down. The priority bumping feature allows the user to select
the timeslot priority (high or low) in this case. The time slots which have
been assigned high priority will continue being sent on the remaining HDSL
line.
Unframed Mode
HCD-E1 can also be operated in an unframed mode: in this mode HCD-E1
accepts a 2048 kbps data stream through the E1 sublink or data channel and
converts it to an unframed G.703 signal for transport over the HDSL link.
Thus, HCD-E1 can also serve as an interface converter and high-speed,
short-distance modem.
When the unframed mode is selected in the E1 sublink, HCD-E1
transparently transfers the data stream received from the E1 port to the main
link. The E1 sublink or data channel must be configured for operation in
unframed mode at a data rate of 2048 kHz, and the other data ports must
be disconnected from the main link.
1.2 Physical Description
HCD-E1 is a compact unit, intended for installation on desktops or shelves.
The unit height is 1U (1.75").
An optional rack-mount adapter kit enables the installation of one or two
HCD-E1 units in a 19" rack.
Figure 1-2 shows the 3D view of HCD-E1.
