Sending media (real-time media) via TCP is not a good idea. TCP is a protocol that gives some gurantees regading the sequence and some other attributes, such as guaranteed delivery. Because TCP sits on top of a non-reliable protocol (IP) and thus employs several techniques to implement these gurantees. TCP uses buffering and sliding windows etc (for more details have a look into the relevant RFC :-) ) and this adds to the delivery and round-trip time. TCP is not a real-time protocol. TCP is also vulnerable to what's called "buffer-bloat" in the Internet. This could lead to a large delay of data and this is a "bad thing" for real time data such as audio/video. UDP does not suffer from these delays, also mostly not from buffer-bloat and is thus much more suited for RTP. Clients must be prepared to handle out-of-order packets and lost data, etc (ordered queues, Jitter buffers etc) Werner Am 20.07.2013 10:42, schrieb Techie Sup: > I believe these requirement have increased since some ISP does not > allow commercial VoIP and they filter traffic and block RTP over UDP. > > Selvam > > On 7/18/13, J Alex Antony Vijay <jfalexvijay at gmail.com> wrote: >> Shall I know why you want use TCP instead of UDP ? >> >> >> On Tue, Jul 16, 2013 at 9:46 AM, Khoa Pham <onmyway133 at gmail.com> wrote: >> >>> Hi, for the SIP transport, pjsip and linphone server do support UDP, TCP >>> But for Media transport, only UDP is supported. If you 'd like to support >>> RTP over TCP, please see transport_udp.c in pjmedia project, and make >>> your >>> own transport_tcp >>> >>> Basically, you will not use UDP socket, but TCP socket for media packet >>> >>> >>> On Thu, Apr 11, 2013 at 11:49 AM, Techie Sup >>> <techsup0073 at gmail.com>wrote: >>> >>>> I too work on similar feature on routing RTP through TCP and please >>>> share your observations if you come across with a working solution. >>>> >>>> Warm Regards >>>> Selvam >>>> >>>> On 4/7/13, gaurav.srivastava2 at agnity.com <gaurav.srivastava2 at agnity.com> >>>> wrote: >>>>> >>>>> Please check http://www.pjsip.org/sip_media_features.htm [1] >>>>> >>>>> On Sun, 7 >>>>> Apr 2013 01:05:49 -0700, Haomiao Huang >>>>> wrote: >>>>>> Sorry, what I meant was >>>>> that the RTP packets were still going out over UDP >>>>>> and not TCP. So the >>>>> SIP messaging packets were definitely TCP, but the >>>>>> media packets were >>>>> still UDP. >>>>>> >>>>>> Any thoughts on why this might be the case? Do I need to do >>>>> something >>>>>> separate in PJSIP to make the RTP go out over TCP as well? >>>>>> >>>>>> >>>>> >>>>>> On Sat, Apr 6, 2013 at 6:08 AM, J Mena wrote: >>>>>> >>>>>>> RTP is the protocol >>>>> used by the application, the rtp packets can be sent >>>>>>> over different >>>>> transpors, udp or tcp >>>>>>> >>>>>>> >>>>>>> >>>>>>> On Apr 5, 2013, at 10:24 PM, "Haomiao >>>>> Huang" >>>>>>> wrote: >>>>>>> >>>>>>> Hi, >>>>>>> I'm trying to get a VOIP app working over >>>>> 3G. It looks like the RTP >>>>>>> packets going to and from the phone are not >>>>> getting through. I would like >>>>>>> to send media using TCP. How would I go >>>>> about doing this, and does the >>>>>>> linphone server support this? I'm using >>>>> sip.linphone.org for my >>>>>>> registration. >>>>>>> >>>>>>> I've enabled TCP transport >>>>> on both clients (standard linphone app on iOS >>>>>>> and pjsua on MacOS). The >>>>> SIP packets go through on TCP but RTP is still >>>>>>> being used for the the >>>>> audio itself. >>>>>>> >>>>>>> Any ideas/thoughts on this? Is it the server that's >>>>> causing this, or do >>>>>>> I need to do something on the client side? Is this >>>>> even a good idea? Any >>>>>>> help would be appreciated! >>>>>>> -Haomiao >>>>>>> >>>>>>> >>>>>>> >>>>> _______________________________________________ >>>>>>> Visit our blog: >>>>> http://blog.pjsip.org >>>>>>> >>>>>>> pjsip mailing list >>>>>>> pjsip at lists.pjsip.org >>>>>>> >>>>> http://lists.pjsip.org/mailman/listinfo/pjsip_lists.pjsip.org >>>>>>> >>>>>>> >>>>>>> >>>>> _______________________________________________ >>>>>>> Visit our blog: >>>>> http://blog.pjsip.org >>>>>>> >>>>>>> pjsip mailing list >>>>>>> pjsip at lists.pjsip.org >>>>>>> >>>>> http://lists.pjsip.org/mailman/listinfo/pjsip_lists.pjsip.org >>>>>>> >>>>>>> >>>>> >>>>> >>>>> Links: >>>>> ------ >>>>> [1] >>>>> http://www.pjsip.org/sip_media_features.htm >>>>> >>>> >>>> _______________________________________________ >>>> Visit our blog: http://blog.pjsip.org >>>> >>>> pjsip mailing list >>>> pjsip at lists.pjsip.org >>>> http://lists.pjsip.org/mailman/listinfo/pjsip_lists.pjsip.org >>>> >>> >>> >>> >>> -- >>> Khoa Pham >>> HCMC University of Science >>> www.fantageek.com >>> >>> _______________________________________________ >>> Visit our blog: http://blog.pjsip.org >>> >>> pjsip mailing list >>> pjsip at lists.pjsip.org >>> http://lists.pjsip.org/mailman/listinfo/pjsip_lists.pjsip.org >>> >>> >> >> >> -- >> >> Regards, >> J Alex Antony Vijay. >> > > _______________________________________________ > Visit our blog: http://blog.pjsip.org > > pjsip mailing list > pjsip at lists.pjsip.org > http://lists.pjsip.org/mailman/listinfo/pjsip_lists.pjsip.org > -- ---------------------------------------------- Werner Dittmann Werner.Dittmann at t-online.de Tel +49 173 44 37 659 PGP key: 82EF5E8B
