Sandeep, Thank you for your very quick response. I have passed your suggestion to my engineer who has confirmed that this is exactly the information he needed. Excellent work. Thanks again... Tim From: pjsip [mailto:pjsip-bounces@xxxxxxxxxxxxxxx] On Behalf Of Sandeep Karanth Sent: 11 January 2013 05:17 To: pjsip list Subject: Re: Custom Session Negotiation Hi Tim, I guess probably you are using below part of transport_encode_sdp() function to add your custom attribute to sdp. if (1) { /* Say we add a proprietary attribute here.. */ pjmedia_sdp_attr *my_attr; my_attr = PJ_POOL_ALLOC_T(sdp_pool, pjmedia_sdp_attr); pj_strdup2(sdp_pool, &my_attr->name, "X-adapter"); pj_strdup2(sdp_pool, &my_attr->value, "some value"); pjmedia_sdp_attr_add(&local_sdp->media[media_index]->attr_count, local_sdp->media[media_index]->attr, my_attr); } I think you are probably substituting in the above block 'X-adapter' with your custom attribute. The problem is that pjmedia_sdp_attr_add function highlighted above is adding that parameter as a media parameter and hence it will come as a media parameter. You can instead substitute the above line with pjmedia_sdp_attr_add(&local_sdp->attr_count,local_sdp->attr,my_attr); and try again. Hopefully this should solve your problem! Regards, Sandeep On Fri, Jan 11, 2013 at 10:20 AM, Sandeep Karanth <sandeepk.kdp at gmail.com<mailto:sandeepk.kdp at gmail.com>> wrote: Correct me if am wrong! So what you are looking to do is to add a session level attribute i.e a=somevalue before any of the media parameter (m) lines but instead it is getting added after some (m) parameter and hence it is effect your custom "a" attribute in effect is becoming a media level attribute?? On Thu, Jan 10, 2013 at 7:40 PM, McLeod, Tim <Tim.McLeod at cassidian.com<mailto:Tim.McLeod at cassidian.com>> wrote: Furthering our project for experimenting with various methods of providing secure VoIP communications we have a need to provide custom negotiation mechanisms. My engineer is currently looking into how this might be incorporated into the existing pjsua functionality. He is encountering difficulties. He is attempting to insert MIKEY session attributes into SDP message, i.e. a=key-mgmt: mikey {base64 encoded mikey message} by using the function "transport_encode_sdp" in the transport adapter to add the desired mikey message. When capturing the SIP invite message in Wireshark, the coding is translated as a media attribute, the suspicion being that this is the case because it is added to the message after the media description. Is there a clean way to add a session description before the media attribute? Your help would (once again) be very much appreciated. Tim McLeod MBCS CITP Principal Engineer Tel: +44 1633 715097<tel:%2B44%201633%20715097> Mob: +44 7765 088364<tel:%2B44%207765%20088364> Email: tim.mcleod at cassidian.com<mailto:tim.mcleod at cassidian.com> RLI: tim.mcleod at eads.r.mil.uk<mailto:tim.mcleod at eads.r.mil.uk> Website: www.cassidian.com<http://www.cassidian.com/> The information contained within this e-mail and any files attached to this e-mail is private and in addition may include commercially sensitive information. The contents of this e-mail are for the intended recipient only and therefore if you wish to disclose the information contained within this e-mail or attached files, please contact the sender prior to any such disclosure. If you are not the intended recipient, any disclosure, copying or distribution is prohibited. Please also contact the sender and inform them of the error and delete the e-mail, including any attached files from your system. Cassidian Limited, Registered Office : Quadrant House, Celtic Springs, Coedkernew, Newport, NP10 8FZ Company No: 04191036 http://www.cassidian.com _______________________________________________ Visit our blog: http://blog.pjsip.org pjsip mailing list pjsip at lists.pjsip.org<mailto:pjsip at lists.pjsip.org> http://lists.pjsip.org/mailman/listinfo/pjsip_lists.pjsip.org The information contained within this e-mail and any files attached to this e-mail is private and in addition may include commercially sensitive information. The contents of this e-mail are for the intended recipient only and therefore if you wish to disclose the information contained within this e-mail or attached files, please contact the sender prior to any such disclosure. If you are not the intended recipient, any disclosure, copying or distribution is prohibited. Please also contact the sender and inform them of the error and delete the e-mail, including any attached files from your system. Cassidian Limited, Registered Office : Quadrant House, Celtic Springs, Coedkernew, Newport, NP10 8FZ Company No: 04191036 http://www.cassidian.com -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.pjsip.org/pipermail/pjsip_lists.pjsip.org/attachments/20130111/37529e06/attachment-0001.html>
