[trimming cc list] Hello Himanshoo,
First, please don't cross-post messages to both the sip list and the sip implementors list. The former is for developing the base protocol and the latter is for questions (like yours) on protocol usage. I'll give my thoughts on your questions below. Himanshoo wrote: > Hi All, > > This is with reference to the mail I wrote yesterday. Kindly read the > scenario explained below and please comment on my understanding / questions. > Also, let me ask my main question again , with reference to > 'draft-ietf-sipping-dialog-package-00': > > Following is quoted from the above mentioned package : > > ------------------------ > Abstract > > This document defines a dialog event package for the SIP Events > architecture, along with a data format used in notifications for this > package. The dialog package allows users to subscribe to another user, and > receive notifications about the changes in state of INVITE initiated dialogs > that the user is involved in. > > ------------------------ > > Can I use this package to receive notification for INVITE initiated dialogs > that the initiator is not invo,ved in ( by using "REFER; method = INVITE") ? I presume you're asking if a UA can monitor a dialog between two or more other UAs using the Dialog Events mechanism. The answer is yes, however, the control this 3rd-party UA may want to perform is limited in this case. More below. > > If not this way then is there some other way , using SIP, in which a > controller(e.g. App Server) is allowed to have monitoring session with a > switching entity (softswitch) for calls which are actually maintained by the > switch but are also monitored for call processing events by the App Server ? There are at least two methods to do this depending on the METHODS support by the softswitch, see below. > > Kindly do comment... > > regards > > Himanshoo > > ----- Original Message ----- > From: "Himanshoo" <[EMAIL PROTECTED]> > To: <[EMAIL PROTECTED]>; <[EMAIL PROTECTED]>; <[EMAIL PROTECTED]> > Sent: Tuesday, September 24, 2002 10:20 AM > Subject: [Sip] certain questions on third party call control ... > > > >>Hi, >> >>I have certain questions related to the scenario explained below. In >>addition to the questions, can somebody please also comment if my >>understanding is correct: >> >>SCENARIO >>------------- >>Caller first dials a service access number and therefore call is given to >>the App Server by switch : >> >>Caller --(INVITE)--> Switch--(INVITE)--> App Server >> >>After this App Server Invites Media Server into the call and collects the >>destination number to which caller wants to talk to . >> >>After getting the destination number , App Server would request the switch >>to connect caller to destination number . But Application Server would >>always like to monitor the call progress (e.g. is and when call was >>answered/terminated/media characteristics changed). So finally it will be >>like this: >> >> App Server >> >> ^ >> | (Monitoring Link) >> >>Caller----> Switch ----->Destination >> >> >>App server acts as controller . After playing the prompt to user, it >>collects digits from user and then it has to connect caller to the called >>party. Now I donot want the to develop a module on App Server, which >>connects two parties in a call, because softswitch already knows how to do >>it.. SO I use REFER (with refer-to field = Destination Number) to ask >> > switch > >>to connect caller to the destination number, and automatically I am >>subscriber for progress of the INVITE which is used to INVITE the >>destination number . In additon I need the following: >> >>1. Capability to do Remote Hang UP : My controller should be able to >>terminate call to the destination if the call duration exceeds 'allowed >>time'. Can I do this using 'REFER ;method = BYE' ? I believe so. Of course, there are authentication and authorization issues here. But REFER only creates a short-lived subscription to report the status of the REFERed method. >>2. After initiating the dialog using 'REFER; method = INVITE', I also need >>to know the progress of dialog. For example if either of caller and called >>party hangsup, I need to stop billing. In other words, I want to subscribe >>for the state of dialogs involving softswitch and Calling/Called Party. >>First I want to know whether I can do this by sending a SUBSCRIBE , using >>dialog package 'draft-ietf-sipping-dialog-package-00.txt'? This would be one way. But you have to implement some logic on the app server so a B2BUA approach is not out of the question in my mind. Using a B2BUA does not require support in other UAs for extension methods, but it does require logic to maintain/manipulate SDPs. >>Also, I want to know whether the dailog state information as per >>'draft-ietf-sipping-dialog-package-00.txt' can also notify me of changes >> > in > >>media characteristics (i.e. SDP for the dialog).? Don't know the answer to this one at the moment without reading the I-D. >>3. Further in another scenario, if the time allowed for the calling user >>(i.e. pre-paid user) expires, and if I want to connect hm to a Media >> > Server > >>for playing some prompt (to decide future course of action) , then can I >> > do > >>this by sending 'REFER ; method = BYE for the dialog between softswitch >> > and > >>called party' and then send 'REFER; method=INVITE for connecting to MRS; >> > In > >>this case if I want to tell MRS to send the digits to APP server, instead >> > of > >>switch , how do I do that? Again, you could use REFER provided the entities involved support it for the methods you'll use. The means to pass data from a media server to an app server is not standardized at this point. I believe the general approach to this would use http. Of course there are other architectures possible. I hope this helps, Bert >> >> >>Best Regards >>Himanshoo >> >>_______________________________________________ >>sip mailing list >>[EMAIL PROTECTED] >>To unsubscribe, please go to http://www.vovida.org/mailman/listinfo/sip >> > > _______________________________________________ > Sip-implementors mailing list > [EMAIL PROTECTED] > http://lists.cs.columbia.edu/mailman/listinfo/sip-implementors > > _______________________________________________ Sip-implementors mailing list [EMAIL PROTECTED] http://lists.cs.columbia.edu/mailman/listinfo/sip-implementors
