SS7-ISUP, DSS1 Call progress message (23/Q.763 (09/97))

A message, sent in either direction during the set-up or active phase of the call, indicating that an event, which is of significance, and should be relayed to the originating or terminating access, has occurred.

ParameterTypeLength (octets)
Message typeF1
Event informationF1
Cause indicatorsO4-?
Call referenceO7
Backward call indicatorsO4
Optional backward call indicatorsO3
Access transportO3-?
User-to-user indicatorsO3
Redirection numberO5
User-to-user informationO3-131
Generic notification indicatorO3
Network specific facilityO4-?
Remote operationsO8-?
Transmission medium usedO3
Access delivery informationO3
Parameter compatibility informationO4-?
Call diversion informationO3
Service activationO3-?
Redirection number restrictionO3
Call transfer numberO4-?
Echo control informationO3
Connected numberO4-?
Backward GVNSO3-?
Generic numberO5-?
Call history informationO4
Conference treatment indicatorsO3-?
UID action indicatorsO3-?
End of optional parametersO1

 DSS1
3.1.8	PROGRESS
This message is sent by the user or the network to indicate the progress of a call in the event of interworking or in relation with the provision of in-band information/patterns. See Table 3-9.
TABLE  3-9/Q.931
PROGRESS message content

Message type: PROGRESS
Significance: global
Direction: both
Information element
Reference (subclause)
Direction
Type
Length
Protocol discriminator
4.2
Both
M
1
Call reference
4.3
Both
M
2-*
Message type
4.4
Both
M
1
Bearer capability
4.5
Both
O (Note 1)
4-12
Cause
4.5
Both
O (Note 2
2-32
Progress indicator
4.5
Both
M
4
Display
4.5
n  ®  u
O (Note 3)
(Note 4)
High layer compatibility
4.5
Both
O (Note 5)
2-5
NOTES
1	The Bearer capability information element is included when the procedures of 5.11 for bearer capability selection apply. The Bearer capability information element indicates the bearer service now being used for the call.
2	Included by the user or the network to provide additional information concerning the provision of in-band information/patterns.
3	Included if the network provides information that can be presented to the user.
4	The minimum length is 2 octets; the maximum length is network dependent and is either 34 or 82 octets.
5	The High layer compatibility information element is included when the optional procedures of 5.12 for high layer compatibility selection apply. The High layer compatibility information element indicates the high layer compatibility now being used for th
e call.