Configuration of outbound Calls in sip.conf


I am using asterisk 1.8 and I have to configure outbound call using sip account. I have to configure seaprate IPs for voice and Signalling.

voice IP is 10.XXX.XX.142 and signalling IP is 10.XXX.XX.150

I have make configuration is sip.conf like this:
context=default ; Default context for incoming calls

And output of route -n is
Destination Gateway Genmask Flags Metric Ref Use Iface
10.XXX.XX.180 10.XXX.XX.150 UGH 0 0 0 eth1 10.XXX.XX.142 UG 0 0 0 eth0

But when I trying to test an outbound call using originate command its not working.Pls guide where I am making mistake.
originate SIP/10.XXX.XX.142/03430XXXXXX application playback vm-goodbye
originate SIP/10.XXX.XX.150/03430XXXXXX application playback vm-goodbye

Logs are below:
== Using SIP RTP CoS mark 5
[Jul 2 14:14:38] WARNING[23561]: chan_sip.c:3821 retrans_pkt: Retransmission timeout reached on transmission … nsmissions
Packet timed out after 32000ms with no response

Many Thanks.