RTP drift with SPA8000 using G.729

[faruk5555]

I have a customer that is using SPA8000 device. We are noticing major RTP drift into the future in the stream coming from the device, something to the order of 1 second a minute. By the end of a 5 minute conversation the timestamp in RTP G.729 packet is almost 6 seconds into the future. Anyone else noticing this behaviour?

Thanks,

Faruk

[Daniele Giordano]

What is the firmware version loaded on SPA8000?

G.729 is more CPU intensive of G.711. What happens if you select G.711?

Regards.

[faruk5555]

Customer does not want to switch to G.711 due to bandwidth requirements. I am not sure what firmware they are running, I assume the latest one (which is not that new time wise) as these got deployed recently, will inquire.

2% drift into the future seems excessive, most oscillators are within +-0.1%.

I am curious as to why would CPU load matter in this case. To me it is more likely that the clocking used is not precise enough for real time applications.

Thanks.