My two SIP trunks are melted for outside calls

Hi,

i’ve something really weird.

  • asterisk1, configured with a phone provider SIP trunk called mytrunk1
  • asterisk2, with the same phone provider, to the same WAN IP but another trunk mytrunk2 (different user/pass)
  • no relationship between these asterisk

When only mytrunk1 is registered all is ok
If i register mytrunk2 (register => user:pass@provider.ip) then when i call somebody using asterisk1 i’m seen as anonymous.

I called my provider to have some debugs and here is what he can see, totally crazy for me !

when i call outside using asterisk1, my provider see that i use mytrunk2 but using mytrunk1 number as callerid, and then this is why it set it as anonymous (i do not have the right to use a number from another trunk, obvious)

For me only the firewall can melt communication (asa5510), no ? My provider tells me that then we would have a user/pass problem.
Maybe something bad configured into sip.conf (nat=force_rport,comedia)

Any idea please ?
Thanks

P.S : i also have an asterisk3 with a 3rd trunk, but from another provider and no problem between asterisk3 and asterisk1&2