[asterisk-users] Aastra 51i and PAP2T behind NAT

[John Millican]

OK this is the RTFM question of the day but I need a sanity check.
I have 2 Astra 51i phone and a linksys PAP2 on a single DSL connection.

2 Aastra 51i---------|
		     |-NAT on dsl moden--(Internet)--Asterisk
PAP2t----------------|

The DSL modem/router which has QOS set for the src and dest to the * box
the PAP2 has both lines registered @ ports 5060 and 5061 and work like a
charm.  one of the the aastra's registered at port 1025 worked all day
but the showed no service and lost registration over night sometime.
this happens with much regularity. I am looking for the docs on these
phones to see if they have a NAT keep alive option.  Does this sound
like a reasonable place to start for a solution?

Thanks in advance
-- 
JohnM