SIP voice service from l2 vlan to internet through SRX345

Hi to all,

 I have a customer who has an SRX345 as a gateway. In its ge-0/0/1 interface has two vlan, the default vlan untagged and the voice vlan tagged. In the voice VLAN, the SRX acts as dhcp server for the phones addressment assignment. The address assignment is working properly and from the PBX we can ping the SIP provider. Also, the phones are able to reach the NTP servers in Internet.

The issue is when I try to call to mobile phones, these calls must be made via SIP provider, but the SIP signaling is dropped with a time out (we can see this in the pbx logs), and the call fails...

I have got configured the interface as you can see here:

    ge-0/0/1 {
        flexible-vlan-tagging;
        native-vlan-id 1;
        unit 0 {
            vlan-id 1;
            family inet {
                address 172.16.1.1/24;
            }
        }
        unit 40 {
            vlan-id 40;
            family inet {
                address 172.16.40.1/24;
            }
        }
    }
vlans {
    VoIP {
        vlan-id 40;
    }
}

These two logical ports are the LAN and the VOIP vlans. These are in the trust zone (which its called "Internal"). Also there is an policy rule that permit all services from trust to untrust. If I search the flow in the logs, I can see this traffic permitted but the calls fails...

Any idea why are failing the call signaling?? Is it correct this vlan definition?? Maybe, is there any other way to configure this scenario??

Thanks in advance!!

Kind Regards!!

David.