Hello,
Thank you everyone one more time for the previous suggestion in regards crossover cable.

My new problem is Cisco and Comdial are trying to negoiate ISDN. The first level of negotiation is completed. However, the second is fail. If I am turning on debug on Cisco it shows that a bad frame is coming from Comdial.
I have two questions: If anybody knows what is it?
The second question: If there is way to turn on any kind of debug on comdial to see ISDN negotiation, similiar what I can see on Cisco Router...

Thank you
Egor

If it is trying to negotiate ISDN then it is looking for a PRI board as I mentioned in my previuos post. You stated you had a T1...you really need to verify the FXII has a PRI board.

It is t1/pri board. We used it as PRI before.

All right then we know you have the right hardware. Have the cisco programmer look at the protocol and make sure you match. Secondly make the Cisco emulate a master/CO status. See where that leads you.