Summary:	ASTERISK-06895: SIP answer 480 is translated incorrectly by hangup_sip2cause
Reporter:	Niels Thomsen (kanoop)	Labels:
Date Opened:	2006-05-04 06:07:53	Date Closed:	2006-05-11 02:41:50
Priority:	Minor	Regression?	No
Status:	Closed/Complete	Components:	Channels/chan_sip/Interoperability
Versions:		Frequency of Occurrence
Related Issues:
Environment:		Attachments:
Description:	hangup_sip2cause is translating a SIP response 480 (temporarily unavailable) into AST_CAUSE_FAILURE.  On a SNOM, when placed in DND (do-not-disturb) mode, this causes the phone to display a "500: Server Error" message, rather than the more sensible "Temporarily Unavailable" message that a 480 response corresponds to. ****** ADDITIONAL INFORMATION ****** This issue appeared in our system when we upgraded from a version 0.9.x to the latest version. I have fixed this in hangup_sip2cause by changing:    case 480: /* No answer */      return AST_CAUSE_FAILURE; into:    case 480: /* No answer */      return AST_CAUSE_NO_ANSWER; However, I do not have enough SIP experience to tell whether this is an appropriate and complete fix.  A brief look around the code seems to indicate that there are no bad side effects from this, but I'd like someone out there to check this.
Comments:	By: Serge Vecher (serge-v) 2006-05-04 08:21:06 kanoop: with this change, does the phone respond correctly? By: Niels Thomsen (kanoop) 2006-05-04 08:29:44 Yes, in so far as it shows a less confusing message to the user.  Showing "Server Error" to a user caused lots of calls to the help desk to report that the pabx had failed, when in fact it was just a normal situation being responded to badly. It could be argued that perhaps AST_CAUSE_BUSY is a more appropriate response, but my users seem to prefer being able to distinguish between someone being "on the phone" and someone being DND. By: Olle Johansson (oej) 2006-05-09 10:26:21 We need to follow the guidelines set by the ISDN to SIP conversion RFCs and guides from Cisco, so the phone need to accept this, sorry. By: Niels Thomsen (kanoop) 2006-05-10 03:41:24 Hmm.. The issue isn't really that the phone doesn't respond properly - which it does - but rather that the mapping of the error code is wrong.   RFC3398, for instance, maps a 480 response to "18 No user responding" which is distinct from its mapping of a 500 response "41 Temporary failure".  So Asterisk mapping a 480 response to "failure" still seems wrong to me... By: Olle Johansson (oej) 2006-05-11 02:41:34 Ok, you're right. Fixed in svn trunk. Thanks!