Nat the port 5060 from two external interface to a single internal

[allenmorton]

Hello

I'm trying to route / NAT the SIP port 5060 from two external interfaces to a single internal ip address but cant seem to get it to work..

I have a cisco 1921 with two adsl modules, both for SIP. What I'd like is something that combines the following two commands into one, as the system wont take these two commands,  it just try's to replace the first with the second. 

ip nat inside source static udp 192.168.1.2 5060 interface Dialer1 5060

ip nat inside source static udp 192.168.1.2 5060 interface Dialer2 5060

[balaji.bandi]

personally I do not believe you able to do this, instead, you can have another  IP address  added device make NAT

ip nat inside source static udp 192.168.1.2 5060 interface Dialer1 5060

ip nat inside source static udp 192.168.2.2 5060 interface Dialer2 5060

EDIT :

after i did some research interestingly look below thread :

https://community.cisco.com/t5/routing/nat-port-translation-from-more-than-one-wan-at-the-same-time/td-p/709405

[allenmorton]

Its on a telephone system which only has one IP address, so need to NAT both external circuits to the same internal IP address.  

I read through the thread https://community.cisco.com/t5/routing/nat-port-translation-from-more-than-one-wan-at-the-same-time/td-p/709405 and have no idea how he got that to work as his nat statements were the same as mine although he was nat'g tcp port 25 and not sip 5060.. But when I programmed the same as the thread details, for testing, the NAT behaved in the same as my NAT statements, the second one overwrites the first.