Answering with inactive may also be used to save bandwidth (in addition to DSP resources as already mentioned) in the call hold scenario. Inactive will force the holding party to stop sending media, leaving the held party to generate proper notification to the user (a message, a special hold tone o whatever else). In my opinion, the hold service model in RFC 3264 is targeted to the MOH one, while it is actually not always really needed. Saving bandwidth is still relevant on the access side, and if you allow the hold service to the user, you need to reserve a 50% more bandwidth/line just to play, for instance, a hold tone. Of course this would require the CPE (and the PSTN gateway) to play "locally" the tone/notification, this would be up to the operator policy (and supported by CPE/gw vendors)
Andrea ---------------------------------------------------------------------- Message: 1 Date: Fri, 20 Feb 2009 11:42:49 -0800 (PST) From: kaiduan xie <[email protected]> Subject: [Sip-implementors] in-active in answer with sendonly in offer To: [email protected] Message-ID: <[email protected]> Content-Type: text/plain; charset=iso-8859-1 Hi, all, What is the purpose of putting inactive in answer when receiving a sendonly offer? Rfc3264 Section 6.1 says, ?? "If a stream is offered as sendonly, the corresponding stream MUST be ?? marked as recvonly or inactive in the answer." In rfc5359, recvonly is returned in hold case. Thanks, kaiduan __________________________________________________________________ Yahoo! Canada Toolbar: Search from anywhere on the web, and bookmark your favourite sites. Download it now at http://ca.toolbar.yahoo.com. _______________________________________________ Sip-implementors mailing list [email protected] https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
