Description
The Cisco SM-X-24FXS/4FXO is a single-wide, fixed-port high-density analog voice service module designed for Cisco ISR 4000 Series routers. It enables seamless integration of legacy analog telephony devices and PSTN connections into modern IP-based voice infrastructures.
Featuring 24 FXS ports for analog endpoints and 4 FXO ports for PSTN or PBX connectivity, this module delivers enterprise-grade voice, fax, and modem services directly from the router. An onboard DSP eliminates the need for external voice processing modules while providing advanced voice features such as echo cancellation, voice compression, jitter buffering, and fax relay.
The SM-X-24FXS/4FXO supports high availability through online insertion and removal (OIR) and includes FXO failover bypass ports to maintain emergency calling during power outages. It is ideal for branch offices, contact centers, and distributed enterprise environments transitioning from analog to IP telephony.
| Specification | Details |
|---|---|
| SKU | SM-X-24FXS/4FXO= |
| Product Type | High-Density Analog Voice Service Module |
| Router Compatibility | Cisco ISR 4000 Series |
| Form Factor | Single-wide SM-X module |
| FXS Ports | 24 (analog phones, fax, modems) |
| FXO Ports | 4 (PSTN / PBX connectivity) |
| FXO Failover Bypass | Supported (4 ports) |
| DSP | Integrated onboard DSP |
| Voice Codecs | G.711, G.729a, G.726, G.722, iLBC, GSM-AMR |
| Fax Support | T.38 relay, fax pass-through |
| Modem Support | Modem pass-through |
| Signaling Protocols | SIP, H.323, MGCP, SCCP |
| Echo Cancellation | Up to 128 ms |
| Online Insertion & Removal | Supported |
| Interfaces | RJ-21 (FXS), RJ-11 (FXO) |
| Power Draw | ~79 W |
| Use Cases | Analog voice gateways, PSTN access, SRST, branch telephony |
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Return Policy (Short Summary)
We offer a 30-day return window for most unopened, factory-sealed items.
Returns must be authorized before shipping back and must include all original packaging and accessories. Opened or used items are not returnable unless defective.
Some products—such as custom orders, special-order items, audio gear, software, and LED video walls—are non-returnable. Non-defective returns may be subject to a 20–30% restocking fee, and customers are responsible for return shipping costs.
For damaged or incorrect items, please contact us immediately.
Building a Complete AV System?
This product is rarely deployed alone. It’s typically part of a fully integrated AV system. AVENDOR designs, integrates, and supports end-to-end environments—from single rooms to enterprise-wide deployments.
- System Design & Engineering
- Installation & Integration
- Programming & Ongoing Support
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