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DTE-A clears the call by deactivating CT108 (for example). As a result TA-A goes on hook and
a `Clear' message is passed through to the SOPHO-LAM. After reception of this message the
SOPHO-LAM deactivates CT109 and CT107. In return MODEM-A goes on hook and
deactivates CT107. MODEM-B detects that the convertor modem is on hook (carrier lost)
and deactivates CT109 and CT107. In return DTE-B deactivates CT108 and MODEM-B goes
on hook.
C.4.4. Call Clearing from the Remote side
Figure
Figure C-7 Call Phase Diagram for Call Clearing from Remote side.
diagram for clearing a call from the ISPBX side.
USER-A
DIGITAL CONNECTION
DTE-A
TA-A
CT109
OFF
CT107
OFF
CT108
OFF
ON HOOK
ON HOOK
Figure C-7 Call Phase Diagram for Call Clearing from Remote side.
DTE-B clears the call by deactivating CT108. As a result MODEM-B goes on hook and
MODEM-A deactivates CT109. The condition of CT109, connected to CT105 of the
SOPHO-LAM, is signalled to CT109 of TA-A via a frame bit. Meanwhile MODEM-A also
deactivates CT107 after which the SOPHO-LAM goes on hook. This is signalled to TA-A using
a `clear' message, after which TA-A deactivates CT107. In return DTE-A deactivates CT108
after which TA-A goes on hook.
108
ISPBX
SOPHO-LAM
VIA FRAME BIT
ON HOOK
CLEAR
CONVERTOR ANALOGUE CONNECTION
MODEM-A
ISPBX
NO SYNC.
CT105
CT109
CT108
CT107
OFF
OFF
CT107
CT108
OFF
OFF
ON HOOK
shows the call phase
USER-B
MODEM-B
DTE-B
CT108
OFF
ON HOOK
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