This is high-level overview of an ISDN call.
Call Setup
993697mS ISDNL3Tx: v=0 peb=5
ISDN Layer3 Pcol=08(Q931) Reflen=2 ref=0011(Remote)
Message Type = Setup
InformationElement = BearerCapability
0000 04 03 80 90 a2
InformationElement = CHI
0000 18 03 a9 83 97
InformationElement = CallingPartyNumber
0000 6c 0c 00 80 33 30 33 35 35 35 31 32 30 34
InformationElement = CalledPartyNumber
0000 70 0b 80 37 32 30 34 34 34 35 32 33 37
Call Handling Information
993737mS ISDNL3Rx: v=0 peb=5
ISDN Layer3 Pcol=08(Q931) Reflen=2 ref=0011(Local)
Message Type = CallProceeding
InformationElement = CHI
0000 18 03 a9 83 97= use B channel 23
Phone rings on the other side
993746mS ISDNL3Rx: v=0 peb=5
ISDN Layer3 Pcol=08(Q931) Reflen=2 ref=0011(Local)
Message Type = Alerting
The other side answers the call
1005111mS ISDNL3Rx: v=0 peb=5
ISDN Layer3 Pcol=08(Q931) Reflen=2 ref=0011(Local)
Message Type = Connect
InformationElement = PI
0000 1e 02 81 82
InformationElement = Shift 6
InformationElement = ??(28)
0000 28 0e 31 73 74 20 32 20 77 69 72 73 20 44 43 50
Speech path established
1005112mS ISDNL3Tx: v=0 peb=5
ISDN Layer3 Pcol=08(Q931) Reflen=2 ref=0011(Remote)
Message Type = ConnectAck
Call disconnected
1007058mS ISDNL3Rx: v=0 peb=5
ISDN Layer3 Pcol=08(Q931) Reflen=2 ref=0011(Local)
Message Type = Disconnect
InformationElement =
0000 08 02 81 90=Cause code 90=Normal call clearing
Channel Released by provider
1007059mS ISDNL3Tx: v=0 peb=5
ISDN Layer3 Pcol=08(Q931) Reflen=2 ref=0011(Remote)
Message Type = Release
Channel free for new use
1007077mS ISDNL3Rx: v=0 peb=5
ISDN Layer3 Pcol=08(Q931) Reflen=2 ref=0011(Local)
Message Type = ReleaseComplete
