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2.2.8 Optional Elements in Q.931 Call SETUP PDU

This section describes optional information elements within an [ITU-Q.931] Call SETUP Request PDU. This request is responsible for call control. The SETUP Request PDU is sent from the calling user to the network and from the network to the called user to initiate a call establishment.

[ITU-Q.931] protocol messages have the following general structure. Optional field usage is described below the following packet diagram.

The Call SETUP Request PDU has following structure:


0


1


2


3


4


5


6


7


8


9

1
0


1


2


3


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5


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9

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0


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9

3
0


1

ProtocolDiscriminator

CallReference

MessageType

Shift (optional)

MoreData (optional)

SendingComplete (optional)

CongestionLevel (optional)

RepeatIndicator (optional)

SegmentedMessage (optional)

BearerCapability

Cause (optional)

CallIdentity (optional)

CallState (optional)

ChannelIdentification (optional)

ProgressIndicator (optional)

NetworkFacilities (optional)

NotificationIndicator (optional)

Display

Date (optional)

Keypad (optional)

Signal (optional)

InformationRate (optional)

EndToEndTransitDelay (optional)

TransitDelay (optional)

PacketLayerBinaryParams (optional)

PacketLayerWindowSize (optional)

PacketSize (optional)

ClosedUserGroup (optional)

ReverseChargeIndication (optional)

CallingPartyNumber (optional)

CallingPartySubaddress (optional)

CalledPartyNumber (optional)

CalledPartySubaddress (optional)

RedirectingNumber (optional)

TransitNetworkSelection (optional)

RestartIndicator (optional)

LowLayerCompatibility (optional)

HighLayerCompatibility (optional)

Facility (optional)

UserToUser

ProtocolDiscriminator (1 byte): Used as specified in [ITU-Q.931].

CallReference (2 bytes): Used as specified in [ITU-Q.931].

MessageType (1 byte): MUST be set to 0x05 for SETUP.

Shift (2 bytes): Not used. MUST be set to 0 and ignored upon receipt.

MoreData (1 byte): Not used. MUST be set to 0 and ignored upon receipt.

SendingComplete (1 byte): Not used. MUST be set to 0 and ignored upon receipt.

CongestionLevel (2 bytes): Not used. MUST be set to 0 and ignored upon receipt.

RepeatIndicator (2 bytes): Not used. MUST be set to 0 and ignored upon receipt.

SegmentedMessage (4 bytes): Not used. MUST be set to 0 and ignored upon receipt.

BearerCapability (4 bytes): Used as specified in [ITU-Q.931].

Cause (4 bytes): Not used. MUST be set to 0 and ignored upon receipt.

CallIdentity (4 bytes): Not used. MUST be set to 0 and ignored upon receipt.

CallState (4 bytes): Not used. MUST be set to 0 and ignored upon receipt.

ChannelIdentification (4 bytes): Not used. MUST be set to 0 and ignored upon receipt.

ProgressIndicator (4 bytes): Not used. MUST be set to 0 and ignored upon receipt.

NetworkFacilities (4 bytes): Not used. MUST be set to 0 and ignored upon receipt.

NotificationIndicator (4 bytes): Not used. MUST be set to 0 and ignored upon receipt.

Display (4 bytes): Used as specified in [ITU-Q.931].

Date (4 bytes): Not used. MUST be set to 0 and ignored upon receipt.

Keypad (4 bytes): Not used. MUST be set to 0 and ignored upon receipt.

Signal (4 bytes): Not used. MUST be set to 0 and ignored upon receipt.

InformationRate (4 bytes): Not used. MUST be set to 0 and ignored upon receipt.

EndToEndTransitDelay (4 bytes): Not used. MUST be set to 0 and ignored upon receipt.

TransitDelay (4 bytes): Not used. MUST be set to 0 and ignored upon receipt.

PacketLayerBinaryParams (4 bytes): Not used. MUST be set to 0 and ignored upon receipt.

PacketLayerWindowSize (4 bytes): Not used. MUST be set to 0 and ignored upon receipt.

PacketSize (4 bytes): Not used. MUST be set to 0 and ignored upon receipt.

ClosedUserGroup (4 bytes): Not used. MUST be set to 0 and ignored upon receipt.

ReverseChargeIndication (4 bytes): Not used. MUST be set to 0 and ignored upon receipt.

CallingPartyNumber (4 bytes): Not used. MUST be set to 0 and ignored upon receipt.

CallingPartySubaddress (4 bytes): Not used. MUST be set to 0 and ignored upon receipt.

CalledPartyNumber (4 bytes): Not used. MUST be set to 0 and ignored upon receipt.

CalledPartySubaddress (4 bytes): Not used. MUST be set to 0 and ignored upon receipt.

RedirectingNumber (4 bytes): Not used. MUST be set to 0 and ignored upon receipt.

TransitNetworkSelection (4 bytes): Not used. MUST be set to 0 and ignored upon receipt.

RestartIndicator (4 bytes): Not used. MUST be set to 0 and ignored upon receipt.

LowLayerCompatibility (4 bytes): Not used. MUST be set to 0 and ignored upon receipt.

HighLayerCompatibility (4 bytes): Not used. MUST be set to 0 and ignored upon receipt.

Facility (4 bytes): Not used. MUST be set to 0 and ignored upon receipt.

UserToUser (4 bytes): Used as specified in [ITU-Q.931].