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Appendix C: Span Telco Settings Reference
Span Telco Settings, continued
Format
Precedence
Channel
Map
T1 CAS,
T1 PRI,
SS7
For incoming calls,
determines the selection
order for using ADDR,
DID, or DNIS as the
destination number for
Voice Firewall Policy
enforcement when multiple
values are present in the call
data.
Affects Policy enforcement.
Framing
Format
T1 Setup,
E1 Setup
T1 CAS,
E1 PRI,
T1 PRI
Must be set to the carrier's
setting to ensure signal
synchronization.
Improper setting causes
telco red alarm, with
absence of dial tone.
Incoming
Numbering
Format
Channel
Map
T1 CAS,
T1 PRI,
SS7
Specifies the format for dial
pulse, MF, or DTMF digits
received by the PBX from
the telephone network
during address/destination
transmission.
* On T1 PRI Spans, this
field determines whether
incoming calls use Direct
Inward Dialing (DID) or
normal address digit
dialing.
* On T1 CAS Spans, this
field indicates which DTMF
or MF strings are present
and the order in which they
occur.
If DNIS or DID is used,
incoming numbering format
must specify that format for
the Dialing Plan to create
normalized numbers.
Affects Policy enforcement.
Line Coding
T1 Setup,
E1 Setup
T1 CAS,
E1 PRI,
T1 PRI
For transmission of binary
digits.
Setting must identical at the
CO, Span, and PBX.
Affects D-channel
operation and audio quality;
can cause telco red alarm
with absence of dial tone.
Line Length
to CO
T1 Setup,
E1 Setup
T1 CAS,
E1 PRI,
T1 PRI
Specifies the cable length
from the Span to the first
transmitter/receiver toward
the CO.
Degrades signal quality.
Line Length
to PBX
T1 Setup,
E1 Setup
T1 CAS,
E1 PRI,
T1 PRI
Specifies the cable length
from the Span to the first
transmitter/receiver toward
the PBX.
Degrades signal quality.
