DTMF -> Digium E1 -> SIP


I have two Asterisk Servers. The primary Asterisk runs with an Digium T410P Quard E1 Card. The second Asterisk is connected via SIP to the primary.

If I call a number out of the PSTN on the E1 Card (e.g. 0049690121XXXX) the call is accepted by the primary Asterisk and got forwared to the SIP-Account on the second Asterisk. Thats okay - thats like it should be. Now I configured a AgentCallBackLogin() Function on the second Asterisk binded to an external 0049690121XXXX number.
If I call that number I can hear the AgentCallBackLogin() prompt. Now I want to type my Agent-Number to login via DTMF and nothing happends. When I press “#” I enable the blind transfer on the first/primary Asterisk. I have disabled that in “features.conf”.
But still, I cant login. It seems that there is a problem in forwarding DTMF from the first Asterisk (with the E1 Card) to the second (SIP).

Anyone could give me handy fixing that Problem?