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Inter-exchange signaling
nChannel
associated signaling (CAS) as No.5,
R1, R2
nanalog and
digital connections
nModern
ISDN exchanges apply SS7(digital), that is a common channel signaling method (CSS) that is discussed later in
its own lecture
nCAS
is divided into line and register signaling:
nLine
signaling:
nline
state between the trunk-links as
nanswer,
clear-forward*, clear-back
nRegister
signaling:
nrouting
information as
nB-number,
A-category, B-status
*A-subscriber on-hook message transmitted to B exchange