Polycom Audio and Video manual Cause Codes, Code Cause Definition

Administrator’s Guide for the V500 System

Q.850 Cause Codes

The following table describes codes that the ISDN switch sends to the V500 system to indicate call status. Although the codes are standardized, each ISDN service provider defines them differently. Because of this, the definitions in the table may not exactly match the messages that you see.

Code	Cause	Definition
1	Unassigned number	The switch received the sent ISDN number in the
		correct format, but no destination equipment uses the
		number.
2	No route to specified	The ISDN exchange does not recognize the
	transit network	intermediate network through which to route the call.
3	No route to	The intermediate network through which the call is
	destination	routed does not serve the destination address.
6	Channel	The specified channel does not provide adequate
	unacceptable	service quality to accept the requested connection.
7	Call awarded and	The user is assigned an incoming call that is being
	delivered	connected to a call channel that has already been
		established for this user and this type of call.
16	Normal call clearing	The originator or receiver of the call has requested that
		it be cleared.
17	User busy	All B channels are in use; the called system
		acknowledges the connection request, but is unable to
		accept the call.
18	No user responding	The destination equipment does not respond to the call,
		so the connection cannot be completed.
19	No answer from user	The destination equipment did not complete the
	(user alerted)	connection within the prescribed time after responding
		to the connection request. The problem is at the remote
		end of the connection.
21	Call rejected	The destination equipment is capable of accepting the
		call, but has rejected it for an unknown reason.
22	Number changed	The ISDN number used to set up the call is no longer
		valid. (The diagnostic field of the message may return
		an alternate address assigned to the called equipment.)
26	Non-selected user	The destination is capable of accepting the call, but did
	clearing	not assign it to the user.
27	Destination out of	A signaling message cannot be delivered because the
	order	interface is not functioning correctly, and the destination
		cannot be reached. This condition might be temporary;
		for example, remote equipment might be turned off.

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