I ran in the same issues as John Todd did some while ago:
http://lists.digium.com/pipermail/asterisk-users/2005-November/129541.html
I use qualify=yes to ping our internal SIP proxies for failover and
therefore I have very low delays, e.g.
Name/usernameHostDyn Nat ACL Port
Christian Schlatter wrote:
I ran in the same issues as John Todd did some while ago:
http://lists.digium.com/pipermail/asterisk-users/2005-November/129541.html
I use qualify=yes to ping our internal SIP proxies for failover and
therefore I have very low delays, e.g.
Name/usernameHost