I have an Adtran 550. I'd like to be able to configure it to forward traffic between an ISDN BRI-U interface and a Frame Relay interface. Anyone got an idea of how to accomplish this?. I have a Cisco 804 router that I'd like to use to forward traffic to a Cisco 1841 router.
Unfortunately, it sounds like you need the ATLAS to convert audio on a BRI to SIP/VoIP in order to send it over the Frame Relay link to the Cisco router. The ATLAS does not support VoIP. The ATLAS can do BRI to PRI switching, but not BRI to SIP.
Sorry, but I don't believe the ATLAS supports what you need.