Thanks Neels, It is it is necessary to mention that  I have used an IP access module as HNB and it is connected to my core. So the RTP packets are received from HNB and I send my RTP packets to HNB (call connection is established before). I have attached my RTP pcap file. I don't know how I can convert this log (RTP packet payloads which you said has IuUP header) to an AMR file.
I have removed the IuUP header (4 bytes) from payload and concatenated all payloads but the result is not a valid AMR bytes!
Also I think osmo-mgw will not be able to convert IuUP bytes to AMR in offline mode.
Can you help me more?

On Fri, Feb 24, 2023 at 3:45 PM Harald Welte <laforge@osmocom.org> wrote:
On Fri, Feb 24, 2023 at 09:15:29AM +0100, Tomcsanyi, Domonkos wrote:
> AFAIR Wireshark cannot play our RTP streams because it has a very limited set of codecs, mostly focusing on regular VoIP audio.

it can play GSM. Our patches for AMR codec support unfortunately were refused
even after everyone assumed the patents had expired and hence no IPR issues
were known anymore.

We'd still love to get AMR codec support in - especailly since wireshark
wouldn't even contain the codec itself but just link to a system-installed
libopencore-amrnb which probably every distribution ships these days.

--
- Harald Welte <laforge@osmocom.org>           https://laforge.gnumonks.org/
============================================================================
"Privacy in residential applications is a desirable marketing option."
                                                  (ETSI EN 300 175-7 Ch. A6)


--
When there is much light, The shadow is deep...