timestamp of RTP packets

[adrian....@i2cat.net]

Hi all,

We are trying to intergrate webRTC in our project and everything seems to work, but I have some problems with the timestamp of the packets.

I've used Wireshark for capturing the packets that the browser sends to the WebRTC server, and when I take a look at the RTCP packets, the NTP timestamp seems to be randomly generated... The values contained in the headers of each packet differ by years, and they are not always progressive (first packet could arrive with timestamp of year 2014 and the second one with timestamp of year 1992). 

I guess that the browser is the one writing this timestamp, right? Is there any way to force that the timestamp comes from an NTP server or from the local machine?

Thanks in advance,

All the best

[Boris Grozev]

On 22/12/2017 08:04, adrian....@i2cat.net wrote:
> Hi all,
>
> We are trying to intergrate webRTC in our project and everything seems
> to work, but I have some problems with the timestamp of the packets.
>
> I've used Wireshark for capturing the packets that the browser sends to
> the WebRTC server, and when I take a look at the RTCP packets, the NTP
> timestamp seems to be randomly generated...

Perhaps you are looking at SRTCP packets? It's easy to get confused, as
the in a Sender Report the timestamp is the first encrypted field, so
the values that come before make sense.

https://tools.ietf.org/html/rfc3711#section-3.4


Regards,
Boris