Cisco HWIC-4T
4-Port Serial HWIC
Product Highlights
Managing legacy WAN connections alongside modern IP infrastructure is a persistent challenge for enterprise and branch-office networks. The Cisco HWIC-4T is a 4-Port Serial High-Speed WAN Interface Card that delivers a cost-effective, high-density solution for serial WAN connectivity on Cisco Integrated Services Routers.
The HWIC-4T provides four Smart Serial ports, each capable of interface speeds up to 8 Mbps, making it well suited for low- and medium-density WAN aggregation, point-to-point leased-line connections, and Frame Relay links. It supports a broad range of protocols — including HDLC, PPP, Async (SLIP), Bisync, and transparent mode — enabling seamless integration of traditional traffic into converged TCP/IP networks.
Flexible cabling options let you connect via V.35, X.21, RS-232, RS-449 (in both DTE and DCE modes), and EIA-530/EIA-530A (DTE only), all through Cisco's proven Smart Serial connector system. The HWIC-4T is supported across the Cisco 1800, 1900, 2800, 2900, 3800, and 3900 Series ISR platforms, fitting into standard HWIC or EHWIC slots. Whether you're aggregating remote-site WAN links, transporting legacy SNA/SDLC or Bisync traffic, or building a console server, the HWIC-4T delivers reliable serial connectivity in a compact, easy-to-deploy module.
Features & Benefits
High-Speed Serial WAN Connectivity
Each of the four serial ports supports interface speeds up to 8 Mbps, providing the bandwidth needed for WAN aggregation and point-to-point links. This enables IT teams to consolidate multiple remote-site connections onto a single router without sacrificing performance.
Multiprotocol Flexibility
The HWIC-4T supports HDLC, PPP, Async (SLIP), Bisync, and transparent protocols. This broad protocol support allows organizations to transport legacy traffic — such as SNA/SDLC and Bisync — across modern IP networks, eliminating the need for costly dedicated leased lines.
Versatile Interface Standards
Using Cisco Smart Serial connectors and separately purchased cables, the HWIC-4T supports V.35, X.21, RS-232, and RS-449 in both DTE and DCE formats, plus EIA-530 and EIA-530A in DTE format. This flexibility lets you adapt to virtually any serial WAN environment without replacing the interface card.
Compact, High-Density Design
At just 79 × 142 × 21 mm, the HWIC-4T packs four serial ports into a single HWIC slot. This compact form factor maximizes chassis density and preserves additional slots for other interface cards, helping you get the most out of your Cisco ISR investment.
Broad Platform Support
The HWIC-4T is supported in HWIC and EHWIC slots across the Cisco 1800, 1900, 2800, 2900, 3800, and 3900 Series Integrated Services Routers. It is compatible with all Cisco IOS Software feature sets, making deployment straightforward across a wide range of branch and campus router platforms.
Deployment Scenarios
WAN Aggregation for Branch Offices
Aggregate multiple serial WAN links from remote sites onto a single Cisco ISR at the hub. The HWIC-4T's four ports at up to 8 Mbps each provide the density and throughput needed for low- to medium-scale WAN concentration without requiring a separate aggregation device.
Legacy Protocol Transport & Network Convergence
Transport traditional SNA/SDLC, Bisync, and other legacy protocols across a converged TCP/IP backbone. The HWIC-4T enables organizations — particularly in financial services and government — to retire expensive dedicated leased lines while maintaining connectivity to legacy systems.
Console Server / Remote Management
Use the asynchronous serial ports to build a console server for out-of-band management of network devices. Connect serial console ports of routers, switches, and other infrastructure equipment to enable remote troubleshooting and configuration over the IP network.
External Dial-Modem Access
Connect external dial modems to the HWIC-4T's asynchronous serial ports to create a low-density dial access server. This is useful for remote dial-in access or backup WAN connectivity in locations where broadband is unavailable or unreliable.
General
Interfaces & Performance
Physical
Environmental
Status Indicators
Compliance
Compatibility
Compatibility Notes
Supported Platforms
The HWIC-4T is supported in HWIC and EHWIC slots on the following Cisco ISR platforms:
- Cisco 1800 Series (modular models)
- Cisco 1900 Series (e.g., 1941)
- Cisco 2800 Series (e.g., 2801, 2811, 2821, 2851)
- Cisco 2900 Series
- Cisco 3800 Series
- Cisco 3900 Series
Minimum IOS Version
- Cisco IOS 12.3(14)T or later (varies by platform; consult Cisco's compatibility matrix for your specific router model).
- Supported in all Cisco IOS Software feature sets.
Cabling
The HWIC-4T uses Cisco Smart Serial connectors. Interface standard is determined by the cable type purchased separately. Common cables include:
CAB-SS-V35MT/CAB-SS-V35FC(V.35)CAB-SS-X21MT/CAB-SS-X21FC(X.21)CAB-SS-232MT/CAB-SS-232FC(RS-232)CAB-SS-449MT/CAB-SS-449FC(RS-449)CAB-SS-530MT(EIA-530, DTE only)
Note: The HWIC-4T uses the same Smart Serial connectors and cabling as the WIC-2T and WIC-2A/S.
Downloads & Resources
Frequently Asked Questions
| Part Number | Product | Key Difference |
|---|---|---|
| HWIC-2T | Cisco 2-Port Serial HWIC | 2-port version at up to 8 Mbps per port — lower density, ideal when only 1–2 serial links are needed |
| HWIC-4A/S | Cisco 4-Port Async/Sync HWIC | 4 low-speed sync/async ports (max 256 Kbps sync per port) — suited for console server and low-speed legacy links rather than high-speed WAN |
| HWIC-8A | Cisco 8-Port Async HWIC | 8 asynchronous-only EIA-232 ports — higher port density for async console/modem applications, but no synchronous or high-speed serial support |
| NIM-4T | Cisco 4-Port Serial NIM | Next-generation 4-port serial module for Cisco ISR 4000 Series (NIM slot) — the successor for customers migrating to ISR 4300/4400 platforms |
