A correct network architecture should consider current and future needs, for this it is precise a modular and redundant design that allows management of changes with a minimum incidence in the service.
The management of a network should be designed to be the less intrusive possible, must not generate excessive traffic nor to affect to the performance.
To give security to the data communications you can achieve it at all network levels and with different technologies, not always should think in implementing the security in the OSI levels corresponding to the IP networks.
Mobility is usually related with wireless networks (Wifi) and with the IP VPN, but is also possible to implement it in a wired network and without the need to establish an IP VPN.
Currently the multiservice operators' networks, that offer quality of service (QoS), are allowing the proliferation of the use of services of Voice over IP and Telephony over IP.
