Xtc Timing And Control Functionality; Xtc Cross-Connect Functionality - Cisco ONS 15327 User Documentation

Chapter 13 Card Reference
The physical connection points are located on the MIC cards. See the
page 13-9

13.3.1.3 XTC Timing and Control Functionality

The XTC cards combine the timing and control functions into one card. You can install the XTC cards
in one or both of the control slots (Slots 5 and 6). XTC cards must be installed in both of the control slots
for redundancy. In a non-redundant configuration, you must install the XTC in Slot 6.
The XTC cards support multichannel, High-level Data Link Control (HDLC) processing for the DCC.
Up to four DCCs can be routed over the serial communication interface (SCI) and terminated at the XTC
card. The XTC cards process ten DCCs to enable remote system management interfaces.
ONS 15327 Release 3.3 supports DCC tunneling of non-Cisco equipment.
Note
The XTC cards also originate and terminate a cell bus carried over the SCI. The cell bus supports links
between any two cards in the system, which is essential for peer-to-peer communication. Peer-to-peer
communication accelerates protection switching for redundant cards.
The XTC cards select a recovered clock from optical line cards, a building integrated timing supply
(BITS), or an internal Stratum 3 reference as the system timing reference.
The node database, IP address, and system software are stored in XTC card non-volatile memory, which
allows quick recovery in the event of a power or card failure.
The XTC cards perform all system-timing functions for each ONS 15327. The XTC cards select a
recovered clock, a building integrated timing supply (BITS), or an internal Stratum 3 reference as the
system-timing reference. You can provision any of the clock inputs as a primary or secondary timing
source. A slow-reference tracking loop allows the XTC cards to synchronize to the recovered clock,
which provides holdover if the reference is lost.
In a redundant configuration, if the working XTC card fails, traffic switches to the protect XTC card. All
XTC protection switches conform to protection switching standards when the bit error rate (BER) counts
are not in excess of 1 E-3 and completion time is less than 50 ms.
The XTC-cards feature an RJ-45 10Base-T LAN port and an EIA/TIA-232 DB9 type craft interface for
user interfaces. The craft port runs at 9600 bps.

13.3.1.4 XTC Cross-Connect Functionality

The XTC card is the central element for ONS 15327 switching. It establishes cross connections and
performs time-division switching (TDS) at the STS-1 and VT1.5 level between ONS 15327 traffic cards.
The switch matrix on the XTC card consists of 288 bidirectional ports. When creating bidirectional
STS-1 cross-connects, each cross-connect uses two STS-1 ports. This results in 144 bidirectional STS-1
cross-connects. The switch matrix is non-blocking and broadcast supporting. This allows network
operators to concentrate or groom low-speed traffic from line cards onto high-speed transport spans and
to drop low-speed traffic from transport spans onto line cards.
matrix for the XTC card.
June 2002
for more information about physical connections.
XTC Cards (XTC-28-3/XTC-14)
"MIC Description" section on
Figure 13-4 shows the cross-connect
Cisco ONS 15327 User Documentation, R3.3
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