How does sipecho.c work?

M
mayamatakeshi
Mon, Jan 27, 2020 1:28 PM

Hi,
I'm going thru the sipecho.c source code and it is not clear to me how it
echoes RTP back to the UAC.
I can see it copies the offer SDP, removes some attributes, leaves a single
codec and replies but I don't see where it handles the incoming RTP packets.

Hi, I'm going thru the sipecho.c source code and it is not clear to me how it echoes RTP back to the UAC. I can see it copies the offer SDP, removes some attributes, leaves a single codec and replies but I don't see where it handles the incoming RTP packets.
M
mayamatakeshi
Mon, Jan 27, 2020 1:43 PM

On Mon, Jan 27, 2020 at 10:28 PM mayamatakeshi mayamatakeshi@gmail.com
wrote:

Hi,
I'm going thru the sipecho.c source code and it is not clear to me how it
echoes RTP back to the UAC.
I can see it copies the offer SDP, removes some attributes, leaves a
single codec and replies but I don't see where it handles the incoming RTP
packets.

Ah, I got it.
Actually sipecho doesn't handle media at all: it just replies with an
answer-SDP where the RTP endpoint in the same as in the offer-SDP.
So the uac sends RTP to its own RTP endpoint.

On Mon, Jan 27, 2020 at 10:28 PM mayamatakeshi <mayamatakeshi@gmail.com> wrote: > Hi, > I'm going thru the sipecho.c source code and it is not clear to me how it > echoes RTP back to the UAC. > I can see it copies the offer SDP, removes some attributes, leaves a > single codec and replies but I don't see where it handles the incoming RTP > packets. > > Ah, I got it. Actually sipecho doesn't handle media at all: it just replies with an answer-SDP where the RTP endpoint in the same as in the offer-SDP. So the uac sends RTP to its own RTP endpoint.