Trusted by the Highest-Stakes Buyers
Federal agencies and Fortune 500 operations source through ORM Systems.
US Government & Defense
Enterprise Clients
Featured Deal
Hand-picked by our procurement team for standout value. This unit is offered at our sharpest price on current stock, verified against live market rates.
Name:
2 In stock - Ready to Ship
Certified Refurbished
Professionally inspected, bench-tested, and firmware-verified, with configurations wiped. Restored to full working order and backed by our warranty.
3 Year Extended Warranty
Same-day Shipping
30-Day Money Back Guarantee
Shipping:
Payment:
3 Year Extended Warranty
Same-day Shipping
30-Day Money Back Guarantee
Need Additional Discount on Product?
Request a quote below - Get Exclusive Pricing and Support.
Shipping:
Payment:
NM-4B-S/T
4Port ISDNBRI Network Module Cisco Router Network Module
Federal agencies and Fortune 500 operations source through ORM Systems.
US Government & Defense
Enterprise Clients
Regional teams and 25+ distribution partners keep stock near you and accountability in your time zone.
Pay by PayPal or Revolut with full chargeback rights. Order on PO terms, Net-30 for government.
Every registration we claim is public record — check our federal contractor status yourself before you spend a dollar.

Ten years serving buyers who audit their vendors. From federal agencies to 20,000+ enterprise clients worldwide.
NM-4B-S/T is a high-performance Ethernet module designed for robust enterprise networking solutions. It features four integrated RJ-45 ports that support data rates of up to 1Gbps per port, and it seamlessly integrates with routers, switches, and servers using standardized TCP/IP and UDP protocols.
NM-4B-S/T is built with a PCIe form factor for easy installation and reliable performance in data centers and enterprise environments. Its optimized design ensures efficient network connectivity for expanding infrastructure capacity, upgrading server interfaces, and connecting to high-speed networks.
NM-4B-S/T price is is available on request. Get immediate quote.
Request bulk order quote for NM-4B-S/T for additional pricing. Browse the full Nm Nme Em Network Modules series or explore all Cisco products.
In a global financial services firm, the Cisco NM-4B-S/T-4Port ISDN BRI Network Module in ISR routers provides a dedicated ISDN BRI backup link for mission-critical trading systems. Automated MLPPP failover delivers sub-second switchover on MPLS or broadband outages, ensuring uninterrupted order execution and market data access. Outcome: Achieves 99.999% uptime, prevents revenue loss during connectivity disruptions, and upholds regulatory SLAs.
A nationwide retail chain deploys the NM-4B-S/T-4Port ISDN BRI Module on Cisco routers at 200 remote outlets to unify PBX voice trunks and data backup on a single platform. Centralized Cisco IOS management and ISDN BRI integration reduce hardware footprint by 30% and simplify WAN operations. Outcome: Streamlines branch deployments in under two weeks, lowers OPEX, and enhances network reliability.
A regional hospital network leverages the Cisco NM-4B-S/T-4Port ISDN BRI Module to establish resilient PSTN voice channels for emergency services. Integrated with Cisco Unified Communications, it provides encrypted call paths and rapid dial-tone failover when IP links degrade. Outcome: Ensures fail-safe emergency call delivery, safeguards patient safety, and aligns with healthcare compliance standards.
Mon–Fri: [09:00-16:00]
Avg. response under 30 mins
| Product Type | Network Module / Network Card | WAN Module | Network Module / Network Card | Network Module | Ethernet Module |
| Module Type | Ethernet | FXO Analog Telephony | Ethernet | Ethernet | Ethernet |
| Connector Type | RJ-45 | RJ-11 | SFP+ | RJ-45 | RJ-45 |
| Supported Protocols | TCP/IP, UDP | SIP / SS7 | TCP/IP | TCP/IP | TCP/IP |
| Form Factor | PCIe | Modular | PCIe | Modular | PCIe |
| Operating Temperature | 0 to 70°C | 0 to 70°C | 0 to 70°C | 0 to 70°C | 0 to 70°C |
| Storage Temperature | -40 to 85°C | -40 to 85°C | -40 to 85°C | -40 to 85°C | -40 to 85°C |
| Input Voltage | 3.3V | 3.3V | 3.3V | 3.3V | 3.3V |
| Compatibility | Routers, Switches, Servers | Cisco / Juniper / Dell | Cisco / Juniper / Arista | Cisco, Juniper, Arista, Dell, HP | Cisco / Juniper / Arista / Dell / HP |
| Supported Features | Auto-negotiation, Wake-on-LAN, Jumbo Frames, QoS | Echo Cancellation / Caller ID / Call Waiting | Auto-negotiation / Wake-on-LAN / Jumbo Frames / QoS | Auto-negotiation, Wake-on-LAN, Jumbo Frames, QoS | Auto-negotiation / Wake-on-LAN / Jumbo Frames |
| Interface Ports | Ethernet | FXO | SFP+ | Ethernet | Ethernet |
| Product Name | NM-4B-S/T | EM2-HDA-4FXO | NM-HD-2V | SM-D-ES3G-48-P | NME-X-23ES-1G |
Every unit is authentic, sourced through trusted and authorised channels, and serial-verified on request. Genuine networking and IT hardware, guaranteed, or your money back.
New products are backed by up to 3 years of extended warranty, and certified refurbished units by up to 3 months, for dependable protection on every order. Coverage is clear, honoured in full, and confirmed on each product page.
If a unit ever falls short, our streamlined RMA process gets a replacement to you fast, with advance replacement available to keep your network running. No jargon, no runaround.
Every device is inspected, bench-tested, and firmware-verified, with configurations wiped before dispatch. Additional testing can be arranged to confirm full working condition on request.
Our specialists assist with compatibility, configuration, licensing, and installation, before and after you buy. Real hardware expertise, whenever you need it.
dispatched quickly and shipped worldwide from regional hubs, fully tracked and insured.
ISDN BRI module delivered stable connectivity.
Clear signaling and reliable operation.
Installed easily and worked as expected.
Good choice for legacy ISDN needs.
Dependable Cisco module.
The NM-4B-S/T is a Cisco router interface module that delivers four ISDN BRI ports for integrated voice and data services on supported Cisco platforms.
The NM-4B-S/T is compatible with Cisco Integrated Services Routers such as the 1800, 2800 and 3800 series, as well as legacy 2600, 3600 and 3700 platforms.
Power down the router, remove the blank faceplate, insert the NM-4B-S/T into an available network module slot, secure with captive screws, and then power the router up.
It provides four independent 2-B+D channels, hardware NT/TE switching, QoS support, and low-latency voice/data integration over a single module.
Each BRI port supports two 64 kbps B-channels and one 16 kbps D-channel for a total of 144 kbps per port.
Yes. The module’s dual B-channels allow concurrent voice and data sessions on each ISDN BRI interface.
In global config mode, enter interface bri <slot>/<port>, set the switch-type, assign an IP or dialer profile, and enable keepalive commands.
ISDN BRI delivers faster call setup, guaranteed E1/T1-like digital quality, integrated voice/data channels, and call-by-call switching at 128 kbps.
Use the commands show isdn status and show interface bri <slot>/<port> to display D-channel status, B-channel activity and error counters.
Yes. A built-in NT/TE switch allows you to configure each ISDN BRI port as either network-terminated (NT1) or terminal equipment (TE).
Under normal load, the NM-4B-S/T draws approximately 5 W from the router’s power supply.
No. The module offloads ISDN channel processing in hardware, preserving the router’s main CPU cycles for other tasks.
Authorized users can obtain IOS images from the Cisco Software Download Center under the router’s product page; a valid service contract is required.
Verify S/T cable wiring, confirm switch-type settings, check D-channel synchronization with show isdn status, and enable debug isdn q921 for diagnostics.
No. The NM-4B-S/T provides built-in NT1 termination for direct connection to the ISDN network; only a standard S/T-cable is needed.