IAX Relatime Problem

Hi,

I installed two Relase Server with Asterisk 1.8.20, setting up an IAX Trunk between the two machines initially using the conf file.
In later on one of the two are in the past with Realtime MySQL support.
Initially, the recording seems to go well, but then on Server B (machine Realtime) come out this Warning:

[Jun 4 10:27:59] WARNING [31952]: chan_iax2.c: 4404 realtime_peer: Failed to parse sockaddr ‘(null)’ for ipaddr of realtime peer ‘ipaddr’

I still do not understand the problem because even back on the old confiogurazione through files, all resumes normal operation.

thanks for your cooperation

Silvio