asterisk users - Jun 2004 - Asterisk and CISCO Gateway

Hello

I have the following structure

			  SIP			             H323 (chan_h323)
	SIP Phone ------------------------> Asterisk/H323
------------------------------------------->
											 CISCO Gateway (CISCO 2610/NM2V-VIC-2BRI)
-------------------------> ISDN
	SCCP Phone --------------------> CISCO CCM V3.3
-------------------------------------->
			SCCP				H323

I have the following problem:

Call from SIP to SCCP and from SCCP to SIP over H323 works fine. When I phone
from SIP to an ISDN Phone (extern) the call is received but no voice is
available after pickup. The Asterisk Server works as h323 Gateway. The Trace
shows that packages are sendet from the SIP - Phone to Asterisk and from the
CISCO Gateway to Asterisk. But the Asterisk doesn't pass the rtp - packages
in both directions (not to the Phone and not to the Gateway).

Can anyone help ?

Thanks Martin Gebhard