WS-C3750G-48TS-E Cisco Catalyst 3750 48 Ports Stackable Switch Rack Mountable

Architectural Overview and Core Hardware Specifications

At its heart, the WS-C3750G-48TS-E is built to deliver non-blocking, wire-speed performance across all its interfaces. Its hardware architecture is optimized for the Gigabit Ethernet era, providing a robust foundation for converged data, voice, and video networks.

Port Configuration and Physical Design

The switch boasts a fixed configuration of 48 10/100/1000BASE-T Ethernet ports, providing ample connectivity for end-user devices, IP phones, wireless access points, and servers. Additionally, it includes four Small Form-Factor Pluggable (SFP) uplink slots for fiber connectivity, enabling long-distance links to network cores or other switches using Gigabit SFP modules (e.g., 1000BASE-SX, LX, LH). The "TS" in its model name denotes "Twisted Pair" and "SFP," indicating this hybrid copper and fiber capability. The device features a 1U rack-mountable form factor, making it efficient in space-constrained racks. Its robust metal construction and variable-speed, fans ensure reliable operation in diverse environmental conditions.

Performance and Switching Fabric

The internal switching fabric of the Cisco 3750G-48TS-E is engineered for high performance. With a total forwarding bandwidth of 32 Gbps and a forwarding rate of up to 38.7 million packets per second (Mpps), it ensures that even under heavy load, latency remains low and throughput remains high. This capacity guarantees line-rate Gigabit speed on all ports simultaneously, preventing bottlenecks in busy network segments. The switch utilizes a store-and-forward switching mechanism, ensuring full error-checking of frames and maintaining network integrity.

Memory and Processing Resources

Equipped with sufficient DRAM and flash memory, the switch supports the full Cisco IOS Software feature set, including advanced security and quality of service (QoS) protocols. The integrated CPU handles control-plane functions efficiently, allowing the dedicated Application-Specific Integrated Circuit (ASIC) to handle the data-plane forwarding at wire speed.

The Revolutionary StackWise Technology

A defining feature that separates the Cisco 3750G Series from ordinary stackable switches is Cisco StackWise technology. This is not simple daisy-chaining; it is a sophisticated backplane creation technology that unifies individual switches.

Creating a Single Logical Unit

Using special, high-speed stack interconnect cables, up to nine Cisco 3750G switches can be joined to form a single, cohesive logical switch. The stack operates as one unified appliance for management, configuration, and routing. This creates a single point of management, a single IP address for administration, and a simplified spanning-tree topology (the entire stack appears as one bridge).

Resilience and Load Sharing

The StackWise interconnect forms a logical ring, providing redundancy. If one stack member fails or a stack cable is disconnected, the ring automatically heals within microseconds, ensuring continuous network operation. Furthermore, bandwidth is aggregated across the stack links, allowing for efficient load sharing of traffic between units and preventing the interconnect from becoming a bottleneck.

Benefits for Network Designers

For network designers, this meant unprecedented scalability. Starting with a single 48-port switch, network capacity could be increased in granular, cost-effective increments. A stack could grow to 432 Gigabit ports, all managed as one device, simplifying operations, reducing management overhead, and enhancing overall network reliability and availability.

Advanced Software Features and Cisco IOS

The Cisco WS-C3750G-48TS-E runs the full, robust Cisco IOS Software, the same operating system found on Cisco's largest enterprise routers and core switches. This provides a consistent operational experience and a deep, comprehensive feature set.

Layer 3 Routing Capabilities

While often deployed as a Layer 2 switch, the 3750G-48TS-E with the appropriate IP Services IOS image supports advanced Layer 3 static and dynamic routing. It can run protocols such as RIP, OSPF, and EIGRP, allowing it to perform inter-VLAN routing and function as a routing aggregation point in smaller networks or branch offices, eliminating the need for a separate router in many scenarios.

Comprehensive Quality of Service (QoS)

The switch offers sophisticated QoS for prioritizing latency-sensitive traffic like voice and video. It supports:

Classification and Marking: Trusts or re-marks traffic based on DSCP, CoS, or IP precedence.
Congestion Management: Uses weighted tail drop (WTD) and multiple egress queues per port.
Congestion Avoidance: Implements Weighted Random Early Detection (WRED).

This ensures that Voice over IP (VoIP) calls remain clear and video streams remain smooth, even during periods of network congestion.

Robust Security Suite

Security is built-in at multiple levels:

Port Security: Limits MAC addresses per port to prevent unauthorized access.
802.1X Authentication: Provides network admission control at the port level.
Access Control Lists (ACLs): Supports standard, extended, and VLAN-based ACLs for granular traffic filtering.
Dynamic ARP Inspection (DAI) & IP Source Guard: Protect against ARP poisoning and IP spoofing attacks.

These features help in creating a secure access layer and enforcing compliance policies.

Ideal Deployment Scenarios and Use Cases

The versatility of the Cisco 3750G-48TS-E made it, and continues to make it in appropriate settings, suitable for a wide range of deployment scenarios.

Enterprise Wiring Closet / Access Layer

Its primary design role was as a high-density access layer switch. Deployed in campus wiring closets, it connected end-user computers, IP phones, and wireless access points, providing Power over Ethernet (note: the 'E' model does not support PoE; the 'P' model does), advanced QoS for voice, and strong security policies at the network edge.

Mid-Sized Business Core / Aggregation

For small to mid-sized businesses, a stack of 3750G switches could effectively serve as the network core, providing inter-VLAN routing, high-speed connectivity to servers, and uplinks to a WAN router or firewall. Its Layer 3 capabilities and stacking resiliency provided a cost-effective, all-in-one solution.

Data Center Server Aggregation

In entry-level or mid-market data centers, this switch was often used for server farm aggregation, connecting racks of servers at Gigabit speeds. Its high throughput, low latency, and support for features like EtherChannel (link aggregation) made it reliable for this task.

Considerations for Modern Deployment

While an enterprise workhorse, it is essential to note that the 3750G Series is considered end-of-life by Cisco. For modern deployments requiring the latest security patches, 10GbE uplinks, or energy-efficient designs, newer platforms like the Cisco Catalyst 9200 or 9300 series are recommended. However, for isolated networks, labs, or as cost-effective infrastructure where latest features are not critical, the 3750G-48TS-E remains a powerful and capable switch.

Comparison Within the 3750G Series Family

The WS-C3750G-48TS-E exists within a broader family of 3750G switches. Key differentiators include:

WS-C3750G-48PS-S: The PoE Variant

The 'PS' model includes Power over Ethernet (PoE) on all 48 ports, allowing it to directly power devices like Cisco IP phones and wireless access points. The 'S' suffix indicates a standard network software image.

WS-C3750G-24TS-E: The 24-Port Variant

For locations requiring fewer connections, the 24-port version offers identical features in a more compact port density, often at a lower cost.

WS-C3750G-12S-E: The SFP-Only Variant

This model features 12 SFP ports only, designed for fiber-rich environments like data center interconnects.

Choosing the Right Model

Selecting between models depended on port density, the need for PoE, and the type of media (copper vs. fiber) required for end-device connections. The 48TS-E offered the ideal balance of high-density copper access with flexible fiber uplinks.