PRI Protocol Overview - Revision history

Webmaster: /* Cause No. 127 - Intel-working, unspecified */

2011-02-25T13:17:21Z

Cause No. 127 - Intel-working, unspecified

← Older revision		Revision as of 13:17, 25 February 2011
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	This cause is used to report a protocol error event only when no other cause in the protocol error class applies.		This cause is used to report a protocol error event only when no other cause in the protocol error class applies.

-	====Cause No. 127 - ~~Intel-working~~, unspecified====	+	====Cause No. 127 - Interworking, unspecified====
	This cause indicates that an interworking call (usually a call to 5W56 service) has ended.		This cause indicates that an interworking call (usually a call to 5W56 service) has ended.

Webmaster: /* Cause (16) */

2010-04-21T21:44:21Z

Cause (16)

Show changes

Webmaster: /* Cause (16) */

2010-04-21T21:41:31Z

Cause (16)

Show changes

Webmaster: /* RESUME REJECT (34) */

2009-08-11T13:36:04Z

RESUME REJECT (34)

← Older revision		Revision as of 13:36, 11 August 2009
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	IEs: Cause, Display		IEs: Cause, Display

-	Direction: Network → user	+	Direction: Network → user

	=== DISCONNECT (69) ===		=== DISCONNECT (69) ===

Webmaster: /* Cause (16) */

2009-08-11T13:35:50Z

Cause (16)

← Older revision		Revision as of 13:35, 11 August 2009
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	* 34 No circuit/channel available		* 34 No circuit/channel available
	* 42 Switching equipment congestion		* 42 Switching equipment congestion
		+
		+	* 99 Unknown cause (quite often a problem with caller ID or caller ID name)

	===Channel identification (24)===		===Channel identification (24)===

Webmaster: /* Cause (16) */

2009-08-11T13:35:08Z

Cause (16)

← Older revision		Revision as of 13:35, 11 August 2009
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	===Cause (16)===		===Cause (16)===
-	The reason a call was rejected or disconnected. A sample of possible cause codes:	+
		+	The reason a call was rejected or disconnected. A sample of possible cause codes:
		+
	* 1 Unassigned number		* 1 Unassigned number
	* 3 No route to destination		* 3 No route to destination

Webmaster: /* Information Elements */

2009-08-11T13:34:58Z

Information Elements

← Older revision		Revision as of 13:34, 11 August 2009
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	=== Bearer capability (4) ===		=== Bearer capability (4) ===
-	Specifies a requested service: packet or circuit mode, data rate, type of information content	+	Specifies a requested service: packet or circuit mode, data rate, type of information content

	===Call identity (16) ===		===Call identity (16) ===
-	Used to identify a suspended call	+	Used to identify a suspended call

	===Call state (20)===		===Call state (20)===
-	Describes the current status of a call in terms of the standard Q.931 state machine	+	Describes the current status of a call in terms of the standard Q.931 state machine

	===Called party number (112)===		===Called party number (112)===
-	The phone number being dialed	+	The phone number being dialed

	===Calling party number (108)===		===Calling party number (108)===
-	The origin phone number	+	The origin phone number

	===Cause (16)===		===Cause (16)===

Webmaster: /* Cause (16) */

2009-08-11T13:34:34Z

Cause (16)

← Older revision		Revision as of 13:34, 11 August 2009
Line 127:		Line 127:
	===Cause (16)===		===Cause (16)===
	The reason a call was rejected or disconnected. A sample of possible cause codes:		The reason a call was rejected or disconnected. A sample of possible cause codes:
-	1 Unassigned number	+	* 1 Unassigned number
-	3 No route to destination	+	* 3 No route to destination
-	6 Channel unacceptable	+	* 6 Channel unacceptable
-	16 Normal call clearing	+	* 16 Normal call clearing
-	17 User busy	+	* 17 User busy
-	18 User not responding	+	* 18 User not responding
-	19 User alerting; no answer	+	* 19 User alerting; no answer
-	22 Number changed	+	* 22 Number changed
-	27 Destination out of order	+	* 27 Destination out of order
-	28 Invalid number format	+	* 28 Invalid number format
-	34 No circuit/channel available	+	* 34 No circuit/channel available
-	42 Switching equipment congestion	+	* 42 Switching equipment congestion

	===Channel identification (24)===		===Channel identification (24)===

Webmaster at 13:33, 11 August 2009

2009-08-11T13:33:52Z

← Older revision		Revision as of 13:33, 11 August 2009
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	Indicates current call state in terms of Q.931 state machine		Indicates current call state in terms of Q.931 state machine
		+
		+	== Information Elements ==
		+
		+	The most important IEs are all multi-byte:
		+
		+	=== Bearer capability (4) ===
		+	Specifies a requested service: packet or circuit mode, data rate, type of information content
		+
		+	===Call identity (16) ===
		+	Used to identify a suspended call
		+
		+	===Call state (20)===
		+	Describes the current status of a call in terms of the standard Q.931 state machine
		+
		+	===Called party number (112)===
		+	The phone number being dialed
		+
		+	===Calling party number (108)===
		+	The origin phone number
		+
		+	===Cause (16)===
		+	The reason a call was rejected or disconnected. A sample of possible cause codes:
		+	1 Unassigned number
		+	3 No route to destination
		+	6 Channel unacceptable
		+	16 Normal call clearing
		+	17 User busy
		+	18 User not responding
		+	19 User alerting; no answer
		+	22 Number changed
		+	27 Destination out of order
		+	28 Invalid number format
		+	34 No circuit/channel available
		+	42 Switching equipment congestion
		+
		+	===Channel identification (24)===
		+
		+	Identify a B channel
		+
		+	===Date/time (41)===
		+
		+	Poorly defined. Not year 2000 compliant!
		+
		+	===Display (40)===
		+
		+	Human-readable text. Can be specified with almost any message to provide text for an LCD display, for example.
		+
		+	===Service Profile Identification (58)===
		+
		+	Contains a Service Profile Identifier (SPID)
		+
		+	===Signal (52)===
		+
		+	Provide call status tones

Webmaster at 13:32, 11 August 2009

2009-08-11T13:32:03Z

← Older revision		Revision as of 13:32, 11 August 2009
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-	=Q.931 Protocol Overview=	+	==Q.931 Protocol Overview==

	Q.931 is ISDN's connection control protocol, roughly comparable to TCP in the Internet protocol stack. Q.931 doesn't provide flow control or perform retransmission, since the underlying layers are assumed to be reliable and the circuit-oriented nature of ISDN allocates bandwidth in fixed increments of 64 kbps. Q.931 does manage connection setup and breakdown. Like TCP, Q.931 documents both the protocol itself and a protocol state machine.		Q.931 is ISDN's connection control protocol, roughly comparable to TCP in the Internet protocol stack. Q.931 doesn't provide flow control or perform retransmission, since the underlying layers are assumed to be reliable and the circuit-oriented nature of ISDN allocates bandwidth in fixed increments of 64 kbps. Q.931 does manage connection setup and breakdown. Like TCP, Q.931 documents both the protocol itself and a protocol state machine.
Line 7:		Line 7:
	The general format of a Q.931 message includes a single byte protocol discriminator (8 for Q.931 messages), a call reference value to distinguish between different calls being managed over the same D channel, a message type, and various information elements (IEs) as required by the message type in question:		The general format of a Q.931 message includes a single byte protocol discriminator (8 for Q.931 messages), a call reference value to distinguish between different calls being managed over the same D channel, a message type, and various information elements (IEs) as required by the message type in question:

		+	== Message Types ==
	The most important messages types are:		The most important messages types are: