Cisco 2600 and 3600 low density voice/fax network modules provide enterprises, managed service providers and service providers the ability to directly connect the PSTN and legacy telephony equipment to existing Cisco 2600 and Cisco 3600 routers. This provides immediate multiservice advantages, such as telephony toll bypass, new packet telephony applications, and full gateway integration within a Cisco AVVID architecture.This is a two-port FXO voice/fax interface card with battery reversal detection and caller ID support (for Europe).