Ah! This means that my advice was wrong. This section of Confluence tells you more:

https://freeswitch.org/confluence/display/FREESWITCH/Codec+Negotiation#CodecNegotiation-MixingMedia/Codecsondifferentlegs(transcoding)

Bote

From: Anthony Minessale
Sent: Saturday, 26 December, 2015 15:20
Subject: Re: [Freeswitch-users] Codec Transcoding issue

add {media_mix_inbound_outbound_codecs=true} to outbound leg or set media_mix_inbound_outbound_codecs=true in vars.xml to make it global.

On Sat, Dec 26, 2015 at 2:16 PM, Sergey Safarov <s.safarov@gmail.com> wrote:

Set 'disable-transcoding'  to 'false' and repeat again

Sergey

On Sat, Dec 26, 2015 at 8:09 AM, Rutu Patel <rutu.patel@inextrix.com> wrote:

Hi Sergey,

Thank you for reply.

In sip profile 3 codecs are defined(G729,PCMU,PCMA) and device A offers G729.
But freeswitch offers only G729 in INVITE.

Please let me know if you want any other informations.

--
Thanks,
Rutu Patel
iNextrix Technologies Pvt. Ltd.
www.inextrix.com

On Thu, Dec 24, 2015 at 9:35 PM, Sergey Safarov <s.safarov@gmail.com> wrote:

Currently freeswitch offers only device A's codec(G729), but freeswitch should offer all 3 

What codecs offers a-leg In first invite?