Features: Product Type: Expansion Module Interfaces/Ports Details: 1 x RJ-21 Connector 8 x Port FXS/DID Spare Product Voice and fax over IP Voice and fax over Frame Relay VoATM Caller-ID support Voice and fax over same port Works with existing phones, faxes, PBXs, and key systems Compatibility: Cisco 2821 Router Cisco 2851 Router Cisco 3825 Router Cisco 3845 Router Parts: 1 year limited Labor: 1 year limited