[Asterisk-Users] Strange behaviour with lost internet connection

[Rob Thomas]

Problem: 
> It seems the situation is improved when I remove the "regsiter => "
> statements in my sip.conf.

Cause:
If your internet connection is down, your DNS isn't working. IF your DNS
isn't working, it won't be able to resolve names. If it can't resolve a
name, it will sit there trying until it times out.

Solution:
Cache names locally - /etc/hosts, or, just use the IP address in the
register string. Note, this _also_ applies to reverse lookups. Make sure
your DHCP server updates your local x.168.192.in-addr.arpa table so that
_reverse_ lookups work as well.

--Rob