Remo- > The bad call quality on the 2G iPhone is a combination of static noise (not > too loud), 'robotic' speech and some short missing bits. > > I gathered some info provided by PJSIP, regarding a single call I made in > case it's helpful: > > Call time: 00h:01m:16s > 1st res in 3667 ms > conn in 14909ms > SRTP status: Not active > Crypto-suite: (null)\n #0 PCMU @8KHz > , sendrecv, > RX pt=0 > > stat last update: 00h:00m:01.497s ago > total 4.3Kpkt 698.8KB (873.6KB IP hdr) @avg=63.4Kbps/79.3Kbps > *pkt loss=26 (0.6%)* > discrd=0 (0.0%) > dup=0 (0.0%) > reord=0 (0.0%) (msec) min avg max last dev > *loss period: 20.000 20.000 20.000 20.000 0.000* > jitter : 0.000 4.626 194.625 24.125 5.505 > TX pt=0 > ptime=20ms One thing that seems to jump out is the call is not actually using G729, as you had mentioned. Instead it's using G711 uLaw. The aggregate bitrate (including IP/UDP/RTP headers) is almost 80 kbps, which would be correct for 20 msec G711. However, 80 kbps is too high for your 2G network max bandwidth, at least according to the bandwidth figures you gave previously. -Jeff > On Mon, May 10, 2010 at 4:09 PM, Jeff Brower <jbrower at signalogic.com> wrote: > >> Remo- >> >> > My iPhone app uses the PJSIP iPhone Audio driver. >> > It works well on 3G & 3GS iPhones, but I am having some voice quality >> issues >> > on 2G iPhones. >> > When making a call with a 2G iPhone, the voice is distorted and it is >> > impossible to have a conversation. >> > >> > Did anyone experince the same issue or has any advise? this can be >> related >> > to PJSIP/PJSIP audio driver or the 2G iPHone CPU. >> >> 2nd-gen iPhones don't have as much CPU horsepower, but that's probably not >> the whole issue. What does the distortion >> sound like? Missing packets? Static? "Cyborg voice"? >> >> -Jeff >> >> >
