SIP to E1 call, replies 200OK instead of 180Ringing

Hi Guys,

I couldn’t find the answer of my question.

I am using Asterisk 1.2.26.1.
I have a problem with calls from SIP to ZAP E1 channels. When call starts it sends 200OK immediatly instead of 180Ringing.
What configuration parameter in sip.cfg and zapata.cfg do I need to use to solve this problem.

I appreciate your reply.

Thanks in advance,
hman.