Ext<->Asterisk<->CiscoVoiceGateway<->CallM

I have a Cisco Voice gateway 2821 . Dialin and dialout over pots is ok. Also inbound pots calls get redirected to Asterisk and to the Call Manager. So far so good.

ext<->Asterisk<->CiscoVoiceGateway<->CallManager<->ext

I want to setup VOIP sessions Between an ext on Call Manager and an ext on Asterisk though the Cisco VG, and the ext rings but there are no voice and the call is drooped .
I added dial-peer for each ext on the Cisco Voice Gateway

!
dial-peer voice 6020 voip
description Asterisk ext6020
destination-pattern 6020
session protocol sipv2
session target ipv4:192.168.1.47:5060
session transport udp
dtmf-relay sip-notify
codec g711alaw
no vad
!
!
dial-peer voice 8529 voip
description Call Manager ext8529
destination-pattern 8529
session target ipv4:192.168.2.124
session transport udp
dtmf-relay h245-signal h245-alphanumeric
codec g711ulaw
clid strip
no vad
!