Dell Sonic WALL NSA 250M Series high-performance, modular Next-Generation Firewalls offer branch offices & distributed enterprises in-depth frontline security, application & user control, network productivity & optional 802.11 dual-band wireless. The NSA 250M acts as the first line of network defense against viruses, Trojans, key-loggers & other application layer attacks, without compromising network performance. The NSA 250M can be extended with a variety of modules, such as T1/E1, DSL & SFP Modules, in order to provide deployment flexibility & additional failover capabilities. By consolidating equipment, the modular solution reduces acquisition & maintenance costs.