Cisco 1-Port T1/Fractional T1 DSU/CSU WAN Interface Card

The HWIC-1DSU-T1 is a compact, high-performance WAN interface card engineered to deliver dependable T1 connectivity with an integrated CSU/DSU. Designed to fit Cisco routers with HWIC slots, this 1-port card streamlines deployment and ongoing management by unifying the router and CSU/DSU into a single network entity. It’s an ideal solution for branch offices, remote sites, and small to mid-size networks that demand reliable data transmission, efficient diagnostics, and straightforward administration. With its integrated CSU/DSU, you can reduce cabling, simplify configuration, and accelerate troubleshooting, all while preserving the familiar Cisco IOS management experience you rely on. The HWIC-1DSU-T1 is built to support fractional T1 configurations, enabling flexible bandwidth optimization to match your real-time needs and budget without compromising performance.

• Integrated CSU/DSU with single SNMP entity – The HWIC-1DSU-T1 merges the CSU/DSU functionality with the T1 interface, letting you manage the router and CSU/DSU as one cohesive SNMP object. This unified management model simplifies monitoring, fault isolation, and configuration changes, reducing the administrative overhead typically associated with separate devices. By presenting a single control plane for both data path and line interface, network teams gain faster visibility into the health of the WAN link and more efficient problem resolution across mixed environments.
• Reliable T1 and fractional T1 connectivity – This 1-port card delivers classic T1 performance with options for fractional T1 deployments, enabling you to tailor bandwidth to your actual needs. Capable of achieving up to 1.544 Mbps on a standard T1 link, the HWIC-1DSU-T1 supports fractional configurations where appropriate, helping you optimize utilization, preserve tie-line capacity, and reduce carrier costs while maintaining consistent latency and predictability for voice, data, and multi-site applications.
• Comprehensive troubleshooting and diagnostics – Built-in diagnostic capabilities empower IT teams to quickly identify and resolve WAN issues. Features include self-test routines, loopback testing (local and remote where supported by the router), and CSU/DSU diagnostic checks that verify line integrity, framing, and data-path health. Detailed status indicators, error counters, and test results provide actionable insights for rapid fault isolation, enabling faster mean time to repair (MTTR) and higher network availability.
• Easy deployment and centralized management – The HWIC-1DSU-T1 is designed for straightforward installation in supported Cisco ISR platforms. With an emphasis on ease of use, administrators can configure and monitor the card using familiar IOS commands and standard Cisco management workflows. The single-SNMP-entity model reduces the number of management points, simplifying alerting, performance monitoring, and inventory tracking across sites. This streamlined approach supports scalable growth as you add remote offices or expand your WAN.
• Versatile use cases with solid ROI – Ideal for branch offices, satellite locations, and small data-center edge deployments, the HWIC-1DSU-T1 delivers a dependable WAN option that supports voice and data services over T1 links. Its integration reduces hardware footprint and management complexity, while fractional T1 support unlocks cost-effective bandwidth provisioning. By enabling reliable connectivity and simplified administration, this card helps organizations accelerate time-to-service, improve user experiences, and maximize the return on existing Cisco investments.

Technical Details of Cisco 1-Port T1/Fractional T1 DSU/CSU WAN Interface Card

• Model: HWIC-1DSU-T1
• Interface: 1-Port T1/Fractional T1 DSU/CSU WAN Interface Card
• Integrated CSU/DSU: Yes, integrated for simplified WAN management
• Management: Single SNMP entity for router and CSU/DSU
• Data Rate: 1.544 Mbps (T1), with fractional T1 options supported by compatible platforms
• Diagnostics: Self-test, loopback tests, CSU/DSU diagnostics
• Compatibility: Designed for Cisco routers with HWIC slots
• Deployment: Suitable for branch offices and remote sites requiring reliable WAN links

How to install Cisco HWIC-1DSU-T1

To install the HWIC-1DSU-T1, follow these general steps that apply to supported Cisco ISR platforms. Always consult your router’s hardware compatibility list and IOS version requirements before installation.

• Prepare the device: Power down the router and unplug it from the power source. Remove the chassis cover if required by your model, and discharge any static electricity by touching a grounded metal surface.
• Locate an available HWIC slot: Identify an open HWIC slot that is compatible with your router model. Confirm that the slot supports the HWIC-1DSU-T1 form factor and that the chassis supports the device’s power and cooling requirements.
• Insert the card: Carefully align the HWIC module with the slot rails and firmly seat it into place. Ensure the connector is fully seated and the card is secured with its mounting screw if required by the chassis design.
• Restore power and verify physical connection: Reattach the router cover if removed, reconnect power, and power up the device. Check that the hardware detects the new HWIC card and that there are no hardware fault indicators on the chassis.
• Configure and validate: Access the router’s IOS and configure the T1 interface as needed (for example, define the appropriate encapsulation, framing, and clocking). Verify the link status with show interfaces and show controllers commands, and confirm that SNMP status reflects the integrated CSU/DSU as a single management entity.

Frequently asked questions

• What is the Cisco HWIC-1DSU-T1? The HWIC-1DSU-T1 is a Cisco 1-port T1/Fractional T1 DSU/CSU WAN Interface Card featuring an integrated CSU/DSU and a single Management entity, designed to fit Cisco routers with HWIC slots and provide reliable WAN connectivity.
• Does it support fractional T1? Yes. In addition to a full T1 connection, fractional T1 configurations are supported on compatible router platforms to optimize bandwidth usage and cost.
• Is it SNMP-manageable? Yes. The router and CSU/DSU are managed as a single SNMP entity, simplifying monitoring, alerting, and configuration management.
• Which devices can use this HWIC? It is intended for Cisco routers that offer HWIC slots and support the HWIC-1DSU-T1 form factor and IOS features; check your model’s hardware compatibility matrix for exact support.
• What troubleshooting features are included? The card provides self-test capabilities, loopback testing, and CSU/DSU diagnostics to help identify line integrity issues, framing problems, and data-path health quickly.