network switch speed

[Paul Ionescu <i_p_a_u_l yahoo com>]

Hi Dan,

Is it possible/desirable to change the work-flow order when switching
networks ? 
Right now, when a switch is initiated, NM deactivates the current working
networking setup, and tries to setup the proposed/user-choosed network.
In the ideal case, the machine will lose connectivity only for few
seconds, but in the worst case, the connectivity is never restored
(for instance, the new selection is not working, dhcp is down, or the key
is wrong, etc).
However, if we change the order of the switch, this can be avoided:
- when initiating a network switch, first try to get a new working
connection (gather IP, dns, Gw), while maintaining the old connection up.
- after successfully acquiring all the network parameters needed for the
new connection, activate the new connection and tear down the old one.
- this will result IMO in zero network down upon a network switch.

I am mainly talking about user initiated switch, but some may even like it
for automatic switching from wireless to wired (when you plug your laptop
in dock).