WS-X6724-SFP Cisco 24 Ports Ethernet Module

Product Overview: Cisco WS-X6724-SFP Ethernet Module

The Cisco WS-X6724-SFP is a high-efficiency Gigabit Ethernet switching module designed to enhance scalability, performance, and reliability in enterprise and data center networks. Built for Cisco Catalyst 6500 Series switches, this module delivers dependable connectivity and advanced traffic handling for demanding network environments.

General Product Information

• Manufacturer: Cisco Systems
• Model / Part Number: WS-X6724-SFP
• Product Category: Gigabit Ethernet Switching Module

Expansion and Port Configuration

This interface module offers flexible expansion options, making it suitable for growing network infrastructures that require modular scalability.

• Total Ports: 24 expansion slots
• Slot Type: SFP (mini-GBIC) for fiber connectivity
• Design Benefit: Supports various SFP transceivers for diverse networking needs

Performance and Traffic Management Features

Optimized for high-throughput environments, the Cisco WS-X6724-SFP ensures consistent performance across distribution, core, and data center layers.

Primary Application Areas

• Enterprise distribution layer networking
• Core network infrastructure
• High-density data center deployments

Interface and Architecture

• Module Class: CEF720
• Scheduler Algorithm: Weighted Round Robin (WRR)

Queue Structure Per Port

• Transmit Queues: 1p3q8T
• Receive Queues: 1q8T (up to 2q8T when used with CEF)

Buffer Memory Allocation

• Receive Buffer: 166 KB
• Transmit Buffer: 1.17 MB

Cisco WS-X6724-SFP Mastering Scalable Gigabit Performance

In the realm of enterprise networking, the ability to scale bandwidth and port density within a proven chassis ecosystem is paramount. The Cisco WS-X6724-SFP Gigabit Ethernet Interface Module stands as a cornerstone solution for organizations leveraging the robust Cisco Catalyst 6500 Series and 6800 Series platforms. This 24-port switching module is engineered to deliver wire-speed Gigabit Ethernet connectivity, offering a critical blend of performance, flexibility, and investment protection for high-density wiring closet, distribution layer, and data center core deployments.

Designed for the versatile 6500-E Series chassis, this module provides twenty-four dedicated Gigabit Ethernet ports, each employing Small Form-Factor Pluggable (SFP) optics technology. This design choice is fundamental, decoupling the physical port from the transceiver type and granting network architects unparalleled adaptability. Whether the requirement is for short-reach copper connections or long-haul fiber runs across different wavelengths, the SFP-based approach ensures the module can be precisely tailored to the specific media and distance requirements of each link, all while maintaining a consistent and high-performance switching fabric.

Core Architectural Features and Hardware Specifications

The Cisco WS-X6724-SFP is more than a simple port aggregator; it is an intelligent, integrated switching entity within the chassis. Its design integrates critical forwarding and queuing intelligence directly on the module itself.

Forwarding Engine and Performance Metrics

At the heart of the module lies a dedicated ASIC that enables distributed forwarding. This architecture is key to the performance of the Catalyst 6500 Series.

Wire-Speed Throughput

Each of the 24 ports is capable of full-duplex Gigabit Ethernet performance, meaning the module can handle a theoretical aggregate throughput of up to 48 Gbps (24 ports x 2 Gbps) when all ports are operating in full-duplex mode. The module's design ensures that this bandwidth is delivered at wire-speed, with no blocking or oversubscription on the module itself.

Switching Fabric Connectivity

The module connects to the chassis backplane via a high-bandwidth channel. In a 6500-E Series chassis equipped with a 720 Gbps switching fabric, the module utilizes dual fabric connections for redundancy and increased throughput, ensuring that the aggregate traffic from all 24 ports has ample bandwidth to the core of the switch without contention.

Hardware Design and Environmental Specifications

The module is built to the exacting standards of Cisco's enterprise hardware. It is a single-slot card, conforming to the physical dimensions required for the Catalyst 6500/6800 chassis. It features a port-side exhaust airflow design (consistent with most 6500 Series line cards), which is crucial for proper thermal management within the chassis. Proper alignment of airflow (port-side exhaust vs. port-side intake) with the chassis and supervisor configuration is essential for preventing overheating and ensuring hardware longevity. The module operates within standard enterprise-grade temperature and humidity ranges, making it suitable for deployment in controlled data center and wiring closet environments.

Deployment Scenarios and Use Cases

The flexibility of the WS-X6724-SFP allows it to serve in multiple critical roles within a hierarchical network design.

High-Density End-User Access Layer

Perhaps its most common deployment is in the wiring closet, aggregating traffic from a large number of end-user devices, such as desktop computers, IP phones, and wireless access points. The 24-port density is ideal for standard rack configurations, and the use of SFPs allows for a mix of 1000BASE-T copper connections for desktops and 1000BASE-SX/LX fiber connections for uplinks or longer runs to nearby buildings.

Distribution and Core Layer Aggregation

In medium-sized networks or as part of a modular block design, this module can effectively serve in the distribution layer. Here, it aggregates access layer switches from multiple closets. Fiber SFP transceivers are typically used here for the longer-distance, higher-bandwidth uplinks. The module's support for advanced routing protocols (when paired with an appropriate supervisor engine) and Quality of Service (QoS) features makes it capable of performing inter-VLAN routing and traffic policy enforcement at this layer.

Data Center Server Connectivity

While later generations offer 10 Gigabit density, the WS-X6724-SFP found significant use in data centers for connecting servers requiring reliable Gigabit Ethernet connectivity. Its high port density per slot and low latency were valuable for server farm deployments. Support for features like IEEE 802.3ad Link Aggregation (EtherChannel) allows for the bundling of multiple ports to create resilient, high-bandwidth connections to critical servers or storage arrays.

Advanced Feature Set and Software Integration

The functionality of the WS-X6724-SFP is unlocked and defined by the Cisco IOS Software or IOS-XE Software running on the chassis supervisor engine. The module supports a comprehensive suite of enterprise features.

Layer 2 Switching Capabilities

The module provides a full complement of industry-standard Layer 2 protocols. This includes IEEE 802.1Q VLAN trunking for segmenting network traffic, IEEE 802.1s Multiple Spanning Tree (MST) and Rapid Per-VLAN Spanning Tree (RPVST+) for creating loop-free topologies, and IEEE 802.3ad EtherChannel for link aggregation. These features form the bedrock of any scalable, resilient switched network.

Quality of Service (QoS) for Traffic Management

In congested network scenarios, QoS is critical. The module supports sophisticated classification, marking, policing, and queuing mechanisms. Traffic can be prioritized based on Layer 2 (CoS), Layer 3 (DSCP), or extended access control lists (ACLs). The module utilizes egress queuing with weighted tail drop (WTD) and shaped round robin (SRR) scheduling to ensure that voice, video, and critical data applications receive the appropriate priority and bandwidth, minimizing jitter and latency.

Security and Access Control

Network security is integrated at the port level. Features include IEEE 802.1X port-based authentication for dynamic VLAN assignment and access control, DHCP snooping to prevent rogue DHCP server attacks, IP Source Guard to prevent IP address spoofing, and dynamic ARP inspection (DAI) to thwart ARP poisoning attacks. These features work in concert to create a robust defense-in-depth strategy at the network edge.

Multicast Efficiency

For applications like live video streaming or financial data distribution, efficient multicast handling is vital. The module supports Protocol Independent Multicast (PIM) in sparse mode (PIM-SM) and leverages Cisco Group Management Protocol (CGMP) or Internet Group Management Protocol (IGMP) snooping to intelligently forward multicast traffic only to ports with registered receivers, conserving bandwidth on the access and distribution layers.

Compatibility and System Requirements

Successful deployment of the WS-X6724-SFP requires careful attention to compatibility within the broader system ecosystem.

Chassis Compatibility

The module is designed for use in specific chassis models. It is compatible with the Catalyst 6500-E Series chassis (e.g., 6503-E, 6504-E, 6506-E, 6509-E, 6513-E) as well as the 6800 Series chassis (6807-XL and 6880-X). It is crucial to verify that the chassis is running a compatible software version and has a supervisor engine that supports the desired feature set.

Supervisor Engine and Software Dependencies

The module requires a Supervisor Engine 720 or Supervisor Engine 2T (or later compatible supervisors) to operate with the full 720 Gbps fabric. The feature set available (e.g., advanced routing, security) is dependent on the IOS Software feature set installed on the supervisor (e.g., IP Base, IP Services, Enterprise Services).

SFP Transceiver Selection and Compatibility

The module requires separately purchased Cisco-certified SFP transceivers. A wide array is available, including:

GLC-T (1000BASE-T): For copper connections up to 100 meters using Cat5e/Cat6 cable.
GLC-SX-MM (1000BASE-SX): Multimode fiber for short-reach connections up to 550 meters.
GLC-LH-SM (1000BASE-LX/LH): Single-mode fiber for long-haul connections up to 10 kilometers.
GLC-ZX-SM (1000BASE-ZX): Extended reach single-mode for distances up to 70 kilometers.

Using Cisco Digital Optical Monitoring (DOM) capable SFPs is recommended, as they provide real-time diagnostic information about the transceiver's temperature, optical power, and bias current.