Cisco Cisco VN 2900 Network Adaptation Interface Installation Guide

A Foreign Exchange Station (FXS) interface connects directly to a standard telephone, fax machine, or 
similar device. This interface supplies ringing voltage, dial tone, and so on to the station. The ports are 
shown in 

, 

To comply with the Telcordia GR-1089 NEBS standard for electromagnetic compatibility and safety, 
connect the 2-port FXS cards (VIC-2FXS and VIC2-2FXS) and 4-port FXS/DID cards (VIC-4FXS/DID) 
only to intrabuilding or non-exposed wiring or cabling. The intrabuilding cable must be shielded and the 
shield must be grounded at both ends.

Each port on the 4-port FXS/DID VIC can be configured as either Foreign Exchange Station (FXS) or 
Direct Inward Dial (DID) when it is used with phones with a Ringer Equivalence Number (REN) load 
of 1 or less. 

If the REN load on any port is greater than 1, all four ports must be configured as either FXS or DID. 
For information about using analog DID with the 4-port FXS/DID VIC, see the 

Cisco 2600XM series, Cisco 2691, Cisco 2800 series, Cisco 3600 series, Cisco 3700 series, and 
Cisco 3800 series routers support DID on the 4-port FXS/DID cards in Cisco IOS Release 12.3(14)T and 
later.

The Cisco 1751 router can support three 4-port FXS/DID VICs, up to a maximum of four DID ports. The 
Cisco 1760 router can support four 4-port FXS/DID VICs, up to a maximum of eight DID ports.

The Cisco ICS 7750 also supports 8 FXS ports on the analog station interface 81 (ASI 81), and 16 FXS 
ports on the ASI 160. See the “Processor Cards Feature Summary” chapter in the 

 document.

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SEE MANUAL BEFORE INSTALLATION

VIC

FXS