What does this mean? asked to transmit frame type 64

Asterisk Asterisk Support
1

[Aug 9 15:49:43] WARNING[24575]: chan_sip.c:6500 sip_write: Asked to transmit frame type 64, while native formats is 0x100 (g729)(256) read/write = 0x100 (g729)(256)/0x100 (g729)(256)
[Aug 9 15:49:43] WARNING[24575]: chan_sip.c:6500 sip_write: Asked to transmit frame type 64, while native formats is 0x100 (g729)(256) read/write = 0x100 (g729)(256)/0x100 (g729)(256)
[Aug 9 15:49:43] WARNING[24575]: chan_sip.c:6500 sip_write: Asked to transmit frame type 64, while native formats is 0x100 (g729)(256) read/write = 0x100 (g729)(256)/0x100 (g729)(256)

2

Without the SDP it is impossible to say what frame type 64 might be, but either your peer is buggy or you have one of the versions that cannot tolerate non-standard codec numbers for telephony events.