LTPH-TP-1044-01, Issue 1
Appendix C - Technical Reference
HXU-358 V1.04
April 6, 2001
57
In a normal system configuration, two HXU-358s are connected to the
HXU-358 backplane. Both multiplexers receive data continuously from the
T1/E1 tributaries and the HMU interface.
The HXU-358 multiplexes 28 T1 or 21 E1 tributaries, or a mixed combination
of T1 and E1 groups, into a single DS3 channel. All T1/E1 tributaries are
full-duplex, four-wire, transform-isolated signals utilizing bipolar signal
levels. All T1 interfaces operate at 1.544 MHz; E1 interfaces operate at 2.048
MHz.
T
IME
-
SLOT
A
SSIGNMENT
S
WITCH
(TSA)
The TSA switch is a 30 by 30 crosspoint switch capable of switching up to 28
T1 (or 21 E1) lines plus two test access lines. (Each T1/E1 interface has four
wires: TXD, TXC, RXD, and RXC). The TSA can reroute any T1/E1 channel
to a different channel number after entering the HXU-358, and can be used to
monitor and test T1/E1 channels. The TSA can also multiplex in an additional
TTL channel from the HMU to the DS3, allowing the HMU to perform
remote inband network management on the DS3 side.
The TSA switch enables any physical port to be allocated to any time-slot in
the DS3 network interface.
M13 M
ULTIPLEXER
The M13 multiplexer interfaces 28 T1/E1 output lines from the Time-slot
Switch Assignment (TSA) to the DS3 channel. The multiplexer contains 28
input ports for T1 or 21 input ports for E1 which are connected to the T1/E1
channels. The outputs of seven DS2 multiplexers are combined together into
a single DS3 stream.
