Ports required for DataDomain to function through a firewall

All,

I read the documentation I could find, and I have the basic Avamar services working through a firewall. However I can't seem to crack DataDomain. From the document I have, it looks like all I need is port 2049/TCP? I've opened that both ways, and I'm getting this:

2013-06-06 13:15:13 avtar Error <10542>: Data Domain server "blabla.com", LSU: avamar-1309992906 open failed DDR result code: 5028, desc: rpc connection failure

Can anyone steer me in the right direction?