authentication retries but never reconnects. I have to reboot the appli
ance to bring tunnel back up.
Found the following in syslogs:
2010-07-07 13:28:34 Local4.Notice 10.0.0.254 :Jul 07 10:22:22 UTC: %ASA-vpn-5-713259: Group = 188.8.131.52, IP = 184.108.40.206, Session is being torn down. Reason: Lost Service
2010-07-07 13:28:34 Local4.Warning 10.0.0.254 :Jul 07 10:22:22 UTC: %ASA-auth-4-113019: Group = 220.127.116.11, Username = 18.104.22.168, IP = 22.214.171.124, Session disconnected. Session Type: IPsec, Duration: 0h:36m:03s, Bytes xmt: 584567664, Bytes rcv: 156692759, Reason: Lost Service
That indeed could be the reason.
Any chance you can apply some sort of shaping? (Bad comes to worse ASA can do it quite decently, but only in outbound direction AFAIR)