Karel DS200, Technical Reference And Installation Manual

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VI.3.A.6. THE SWITCHING STRUCTURE OF DCC
Intra-rack and inter-rack switching in the DS200L system are conducted over the UTIL200
card, whereas inter-tower switching (switching between towers) is conducted over DCC.
The DCC block has a 4096 x 4096 switching matrix. By this way, 8192 channels in the
DS200L exchange can be simultaneously used for conversations.
The switching matrix on the DCC block is distributed to the TW200 towers over E1 lines in
DCC. Thanks to the isolated E1 structure, trouble-free connections can be established even
with the distant TW200 towers.
Due to its structure, DCC is continuously in communication with both the TW200 towers and
the PCU block. It communicates with the towers over E1 connection, whereas it
communicates with the PCU block over TCP/IP.
Number of 8E1 cards to be installed depends on the capacity of the exchange to be used. At
most 14 DCC 8E1 Interface cards can be installed in the DCC block. By this way, the
capacity may vary between 8 E1 and 112 E1 lines. If the capacity provided by only a single
DCC is not enough, then it may be expanded by including a second DCC in the system, so
that both the switching capacity is increased from 4096 x 4096 to 8192 x 8192, and number
of E1 lines is increased up to 224.
The E1 lines in the DCC are used to establish speech channel connection with the TW200
towers. 1 to 12 E1 lines can be connected to each tower, depending on capacity
requirements. (Each E1 has 31 channels.) By this way, it is possible to provide 31 to 372
speech channels for 672 extensions. Number of the E1 lines to be allocated to towers is one
of the most important parameters that determine capacity of the exchange.