Ubuntu 12.04
Twinkle 1:1.4.2-2.1

I want to run twinkle. I got the sip data, and entered them in
the twinkle editor form.

When I run Twinkle I get this error message
twinkle failed to create a UDP socket (SIP) on port 5060 address already in use

I already got a voip sip phone that came with
the router and internet provider. In the router settings I can see, that sip port
5060 is already used by that sip phone.

Can I use another port for the sip twinkle phone, and how would that be