asterisk:No compatible codecs, not accepting this offer!

perform asterisk -r open asterisk Console

When the client soft phone registers the extension, the following error is displayed

chan_sip.c:8876 process_sdp: No compatible codecs, not accepting this offer!

It could be asterisk The configured encoding does not support
In phone configuration , Configuration allows all encodings
For example, my phone is configured in sip.conf in ,

[general]
context = default
bindport = 5065
bindaddr = 0.0.0.0
tcpbindaddr = 0.0.0.0
tcpenable = yes

[1001]
type = friend
callerid = User One
username = 1001
secret = 1001
host = dynamic
canreinvite = no
context = from-ipphone
dtmfmode = rfc2833
mailbox = 1001
allow=all
;disallow = all
;allow = ulaw
;transport = udp

[1002]
type = friend 
callerid = User Two
username = 1002
secret = 1002
host = dynamic
canreinvite = no
dtmfmode = rfc2833
mailbox = 1002
context = from-ipphone
allow=all
;disallow = all
;allow = ulaw
;transport = udp

Add a row allow = all , Change it to ：

[general]
context = default
bindport = 5065
bindaddr = 0.0.0.0
tcpbindaddr = 0.0.0.0
tcpenable = yes

[1001]
type = friend
callerid = User One
username = 1001
secret = 1001
host = dynamic
canreinvite = no
context = from-ipphone
dtmfmode = rfc2833
mailbox = 1001
;disallow = all
allow = ulaw
;transport = udp

[1002]
type = friend 
callerid = User Two
username = 1002
secret = 1002
host = dynamic
canreinvite = no
dtmfmode = rfc2833
mailbox = 1002
context = from-ipphone
;disallow = all
allow = ulaw
;transport = udp