Hi the problem is that if you send one voice frame (ptime=20 ms) the overhead for RTP/UDP/IP corresponds to 16 kbps. On top of that you have the codec bitrate so the total bitrate will be around 30 kbps. A GPSR link can be as low as 8 kbps. Try increasing ptime to 160 ms (will give more delay) and switch to a better codec like AMR-NB. Finally you have no QoS in GPRS so packet delay can be huge up to 10 s sometimes. BR/Olle Fr?n: pjsip-bounces at lists.pjsip.org [mailto:pjsip-bounces at lists.pjsip.org] F?r Idy Thiam Skickat: den 28 juni 2011 12:15 Till: pjsip at lists.pjsip.org ?mne: [pjsip] high RTP packet loss rate when using GSM over GPRS Hi All, I am trying to use pjsip with a GSM module to communicate with a remote server. When using ADSL, there is no packet loss but with GPRS link, I have something like 80% loss. I think this is due to the fact that RTP is encapsulated into UDP, and there is no reliability, nor integrity. I have a 8Khz sound chip, and use gsm codecs. I think adapting rtp flow could be helpful, but I don t know how to handle it. Any help? -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.pjsip.org/pipermail/pjsip_lists.pjsip.org/attachments/20110628/db248709/attachment.html>
