Specifications

Watson TDM
Operating Manual
Watson-TDM-Manual-W.doc
Version 2.0-01
3-6
Revision: 2008-02-07
CRC-4 and E-bit insertion are supported in framed mode:
CRC4
• If enabled, the E1 framer synchronizes on CRC4 multiframes and CRC4 er-
rors are reported. In the outgoing E1 signal the framer generates the CRC4
multiframe alignment and checksum words. The A-Bit and the Sa-Bits pass
transparently.
• If disabled, the international bits are set to ‘1’ in the outgoing E1 signal. All na-
tional bits are fully transparent. On the receive side, the E1 framer synchro-
nizes on basic frames only and no CRC4 errors are reported.
E-bit Insertion
• If automatic E-Bit generation is enabled, detected CRC4 errors will cause the
assertion of the E-bits.
• If disabled, all E-Bits are set to ‘1’.
3.2.2 AIS Detection
If AIS detection is enabled, receiving AIS from the E1 side causes the following
actions:
• The Non-Urgent alarm is activated (AIS-S).
• AIS is transmitted to the remote station by sending AIS-R over the DSL
With AIS detection disabled AIS from the E1 interface is ignored.
3.2.3 AIS Generation
If this option is enabled, AIS is sent over the local E1 interface if
• the DSL link to the remote station is not established (loss of signal or loss of
frame alignment on DSL side) or
• the remote station is sending AIS-R.
If AIS generation is disabled, no signal is transmitted on the E1 side. The E1 in-
terface will be switched off if either of these two conditions arises.
AIS Generation can also be set to transparent: in this mode AIS is sent on the lo-
cal E1 interface if AIS is signaled from the remote interface (reception of AIS-R).
The local E1 interface is switched off if the DSL link looses synchronization.