The Cisco 1700 series module access routers are the cost effective integrated access platform for small and medium sized businesses and enterprise small branch offices. 

These IOS based routers deliver high speed network access, comprehensive security features and multiservice data/voice/video/fax integration to meet the most demanding business needs. 

In addition, the 1700 series supports a diverse set of WAN interface cards (shared with the 1600, 2600 and 3600 series routers) that enables field upgradability to evolve with the needs of a growing business. 

Models:

1710 - advanced routing and security in one device when attached to the internet using a broadband modem.  Hardware assisted 3DES VPN encryption at full T1/E1 speeds.

1721 - a secure data-only access solution that readily adapts.  Supports data applications including VPN's.  Supports a wide variety of WAN services (Frame Relay, Leased Line, ADSL, G.SHDSL, ISDN, BRI, X.25, SMDS and more).  Provides 3DEC VPN encryption at full T1/E1 speeds.)

1751 - all of the above - plus analog and digital voice support as well as three modular slots for WAN interface cards.

1760 - all of the above - plus rack-mountability, 4 expansion slots and higher density analog and digital voice support than the 1751.