Q.931 Progress Information Element

The Progress Information Element provides one or more octets that describe events that occur during the life of the call.

Progress Format

The Progress IE is variable length with the following format:

8	7	6	5	4	3	2	1	Octet
0	Progress IE (0x1E)							1
length of the Progress Information								2
1	coding std.		0	Location				3
1	Progress description							4

NOTE: Bit 8 of octets 3 and 4 above is the Extension bit and is coded as follows:

• Extension bit = 0 more information for this field follows.
• Extension bit = 1 last octet of this field.

Coding Standard

7	6	Meaning
0	0	ITU standardized coding
1	1	Standard specific to Location field

Location

4	3	2	1	Meaning
0	0	0	0	User
0	0	0	1	Private network serving location user
0	0	1	0	Public network serving local user
0	0	1	1	Transit network
0	1	0	0	Public network serving remote user
0	1	0	1	Remote private network
0	1	1	1	International network
1	0	1	0	Network beyond interworking point

Progress Indicator

The following table shows the hexadecimal value with the extension bit set, without the extension bit set and the decimal value (without the extension bit set).

Hex w Ext	Hex wo Ext	Dec	Meaning
0x81	0x01	1	Call is not end-to-end ISDN or may be in-band information
0x82	0x02	2	Destination call address is non-ISDN
0x83	0x03	3	Origination call address is non-ISDN
0x84	0x04	4	Call has returned to the ISDN
0x88	0x08	8	Inband treatment has been applied
0x8A	0x0A	10	Delay in response at the call interface

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