site a
show configuration security ipsec 
vpn-monitor-options {
    interval 15;
    threshold 15;
}
proposal IPSEC-PRO {
    protocol esp;
    authentication-algorithm hmac-md5-96;
    encryption-algorithm 3des-cbc;
}
policy IPSEC-POL {
    proposals IPSEC-PRO;
}
vpn VPN-SOORTY {
    bind-interface st0.0;
    vpn-monitor {
        optimized;
    }
    ike {
        gateway gw-soortybd;
        ipsec-policy IPSEC-POL;
    }
    establish-tunnels immediately;
}

site b

proposal IPSEC-PRO {
    protocol esp;
    authentication-algorithm hmac-md5-96;
    encryption-algorithm 3des-cbc;
}
proposal IPSEC-PRO-BANGLA {
    protocol esp;
    authentication-algorithm hmac-md5-96;
    encryption-algorithm 3des-cbc;
}
policy IPSEC-POL {
    proposals IPSEC-PRO;
}
policy IPSEC-POL-BANGLA {
    proposals IPSEC-PRO-BANGLA;
}

vpn IPSEC-15-VPN {
    bind-interface st0.15;
    ike {
        gateway IKE-U15-GW;
        ipsec-policy IPSEC-POL-BANGLA;
    }
    establish-tunnels immediately;
}