EXFO FTB-1, User Manual

Page: 366 / 675

Test Results
354
FTB-700G/800 Series
ISDN Logger
Layer 3 messages

SETUP
message is sent by the calling user to the network and by
the network to the called user to initiate call establishment.

CALL PROCEEDING
message is sent by the called user to the
network or by the network to the calling user to indicate that
requested call establishment has been initiated and no more call
establishment information will be accepted.

ALERTING
message is sent by the called user to the network and
by the network to the calling user to indicate that called user
alerting has been initiated.

CONNECT message is sent by the called user to the network and
by the network to the calling user, to indicate call acceptance by
the called user.

CONNECT ACK
message is sent by the network to the called user
to indicate the user has been awarded the call.

DISCONNECT
message is sent by the user to request the network
to clear an end-to-end connection or is sent by the network to
indicate that the end-to-end connection is cleared.

RELEASE message is sent by the user or the network to indicate
that the equipment sending the message has disconnected the
channel (if any) and intends to release the channel and the call
reference. Thus the receiving equipment should release the
channel and prepare to release the call reference after sending a
RELEASE COMPLETE.

RELEASE COMPLETE message is sent by the user or the network
to indicate that the equipment sending the message has released
the channel (if any) and call reference, the channel is available for
reuse, and the receiving equipment shall release the call
reference.