Technical Specifications:

• Part Number: WS-C3550-48-SMI
• UPC: 00746320674407
• Product Line: Cisco Catalyst 3550 Series Intelligent Ethernet Switches
• Form Factor: 1RU (1U) rack-mountable or desktop deployment
• Management Type: Fully Managed Layer 3/4 Multilayer Switch
• Software: Standard Multilayer Image (SMI) installed, upgradeable to Enhanced Multilayer Image (EMI)

Port Configuration:

Fast Ethernet Access Ports:

• 48 x 10/100BASE-TX Ports: Auto-sensing RJ-45 Ethernet ports
  • IEEE 802.3 Type 10BASE-T (10 Mbps)
  • IEEE 802.3u Type 100BASE-TX (100 Mbps)
  • Auto-negotiation for speed and duplex
  • Auto-MDI/MDIX for automatic cable detection
  • Half-duplex or full-duplex operation

Gigabit Uplink Ports:

• 2 x GBIC-Based Gigabit Ethernet Ports: Hot-swappable GBIC module slots
  • Support for multiple GBIC transceiver types:
    • Cisco GigaStack GBIC for high-speed stacking
    • 1000BASE-T (copper Gigabit)
    • 1000BASE-SX (multimode fiber, 850nm, up to 550m)
    • 1000BASE-LX/LH (single-mode/multimode fiber, 1310nm, up to 10km)
    • 1000BASE-ZX (single-mode fiber, 1550nm, up to 70km)
    • CWDM (Coarse Wavelength Division Multiplexing) GBICs

Total Connectivity: 50 maximum ports (48 Fast Ethernet + 2 Gigabit)

Performance Specifications:

• Switching Capacity: High-performance, non-blocking architecture
• MAC Address Table: 8,000 MAC address entries
• Packet Buffer: 1.5 MB shared memory buffer
• Flash Memory: 16 MB (upgradeable)
• SDRAM: 64 MB (standard)
• Throughput: Wire-speed forwarding on all ports simultaneously

Standard Multilayer Image (SMI) Features:

The SMI software provides comprehensive Layer 2-4 functionality including:

Layer 3 Routing:

• Static IP Routing: IPv4 static routes (up to 256 routes)
• RIP v1/v2: Routing Information Protocol for dynamic routing
• Inter-VLAN Routing: Route traffic between VLANs without external router
• IPv4 Routing: High-performance hardware-based IP routing

Note: For advanced routing protocols (OSPF, EIGRP, BGP, multicast routing), upgrade to Enhanced Multilayer Image (EMI) required.

Layer 2 Features:

VLAN Support:

• IEEE 802.1Q VLAN Tagging: Standards-based VLAN implementation
• Maximum VLANs: Up to 250 active VLANs, 4,096 VLAN IDs
• VLAN Trunking Protocol (VTP): Simplifies VLAN configuration management
• Private VLANs: Enhanced security through port isolation

Spanning Tree Protocols:

• IEEE 802.1D STP: Standard Spanning Tree Protocol
• IEEE 802.1w RSTP: Rapid Spanning Tree Protocol
• PVST+ (Per-VLAN Spanning Tree Plus): Cisco proprietary enhancement
• BackboneFast, UplinkFast, PortFast: Rapid convergence features

Link Aggregation:

• Fast EtherChannel: Bundle up to 8 ports for increased bandwidth
• Gigabit EtherChannel: Aggregate Gigabit links for high-speed trunking
• IEEE 802.3ad LACP: Link Aggregation Control Protocol support

Quality of Service (QoS):

Advanced Traffic Management:

• Layer 2-4 Classification: Classify traffic based on MAC address, IP address, DSCP, CoS, TCP/UDP ports
• IEEE 802.1p CoS: 4 hardware queues per port with strict priority and WRR scheduling
• DSCP Marking: Differentiated Services Code Point classification
• Ingress Policing: Rate limiting based on traffic classification
• Auto QoS: Automatic QoS configuration for Cisco IP phones
• Rate Limiting: Bandwidth control per port or per flow

Security Features:

Advanced Access Control:

• Access Control Lists (ACLs): Layer 2/3/4 packet filtering
  • IP ACLs based on source/destination IP, protocol, port
  • MAC ACLs for non-IP traffic
• IEEE 802.1X Port-Based Authentication: Standards-based network access control
• RADIUS/TACACS+ Support: Centralized authentication
• Port Security: Limit MAC addresses per port
• DHCP Snooping: Protection against rogue DHCP servers
• Dynamic ARP Inspection: Prevent ARP spoofing attacks
• IP Source Guard: Block IP address spoofing

Secure Management:

• SSHv2: Encrypted remote CLI access
• SNMPv3: Secure network management protocol
• HTTPS/SSL: Encrypted web-based management

Stacking & High Availability:

Cisco GigaStack Technology:

• Stack up to 9 switches using GigaStack GBIC modules
• Single IP address for entire stack
• Resilient stacking with redundant links

Cluster Management Suite (CMS):

• Manage up to 16 Catalyst switches as single logical cluster
• Web-based configuration and troubleshooting
• Configuration wizards for converged networks

Redundant Power:

• Optional Cisco Redundant Power System 300 (RPS 300) support
• Hot-swappable redundant power for maximum uptime

Management & Monitoring:

Management Interfaces:

• Web-Based GUI: Intuitive browser-based management via Cisco Cluster Management Suite
• Command Line Interface (CLI): Full-featured console and Telnet/SSH access
• SNMP: v1/v2c/v3 for integration with network management systems
• RMON (Remote Monitoring): Proactive network monitoring and troubleshooting

Monitoring Features:

• Port Mirroring (SPAN): Copy traffic to network analyzer
• RSPAN: Remote SPAN across VLANs
• Syslog: Comprehensive event logging
• Link Layer Discovery Protocol (LLDP): Automatic device discovery

Physical Specifications:

• Form Factor: 1RU (1.8 inches / 4.45 cm) rack-mountable
• Dimensions (W × D × H): 17.5" × 16.3" × 1.8" (44.5 × 41.4 × 4.45 cm)
• Weight: Approximately 13 lbs (5.9 kg)
• Mounting: Standard 19-inch EIA rack with included hardware, or desktop placement

Power Supply:

• Input Voltage: Auto-ranging 110V AC or 220V AC (100-240V, 50/60 Hz)
• Power Consumption: Approximately 60W (varies by configuration and load)
• Redundant Power: Optional RPS 300 support for enhanced availability

Environmental Specifications:

• Operating Temperature: 32°F to 113°F (0°C to 45°C)
• Storage Temperature: -13°F to 158°F (-25°C to 70°C)
• Operating Humidity: 10% to 85% (non-condensing)
• Storage Humidity: 10% to 95% (non-condensing)
• Altitude: Up to 10,000 feet (3,000 meters)

Standards & Certifications:

• IEEE Standards: 802.1D, 802.1p, 802.1Q, 802.1w, 802.1X, 802.3, 802.3ab, 802.3u, 802.3x, 802.3z
• Safety: UL 60950, CSA 22.2 No. 60950, EN 60950, IEC 60950
• EMC: FCC Part 15 Class A, EN 55022 Class A, VCCI Class A, AS/NZS 3548 Class A
• Environmental: NEBS Level 3 compliant (certain models)

Ideal Applications:

• Enterprise Wiring Closets: Access layer switching for medium-sized enterprise networks
• Small Network Backbone: Distribution and core switching for mid-sized businesses
• Branch Office Networks: Complete Layer 2/3 infrastructure for remote locations
• Metro Access Edge: Service provider edge deployments
• Campus Networks: Building or departmental switching with routing capabilities
• Converged Networks: Unified data, voice, and video infrastructure with QoS
• VoIP Deployments: Auto QoS for Cisco IP phones

What's Typically Included:

• 1 x Cisco Catalyst WS-C3550-48-SMI switch
• 1 x AC power cord
• 1 x Rack-mount kit
• 1 x Console cable (RJ-45 to DB-9)
• Quick start guide and documentation
• Standard Multilayer Image (SMI) software pre-installed

Optional Accessories (Sold Separately):

• RPS 300: Redundant Power System for enhanced availability
• GBIC Transceivers: Various fiber and copper GBIC modules
• EMI Upgrade Kit: Enhanced Multilayer Image software upgrade
• Fiber Optic Cables: Single-mode and multimode fiber cables
• Rack-Mount Kits: Additional mounting hardware

Software Upgrade Path:

Enhanced Multilayer Image (EMI) Upgrade: Customers can upgrade from SMI to EMI to unlock additional features:

• Advanced IP Routing: OSPF, EIGRP, BGP, policy-based routing
• IP Multicast Routing: PIM (dense, sparse, sparse-dense mode), IGMP v2/v3
• WCCP: Web Cache Communication Protocol
• Fallback Bridging: Bridge non-routable protocols

End-of-Life Status:

Important: The Cisco Catalyst 3550 Series has reached End-of-Sale and End-of-Life status. For new deployments, Cisco recommends:

• Catalyst 9200 Series: Modern replacement with advanced features
• Catalyst 1000 Series: Budget-friendly SMB option
• Catalyst IE3x00 Series: Ruggedized industrial environments

Refurbished WS-C3550-48-SMI units remain widely available through resellers and provide cost-effective solutions for budget-conscious organizations.

Warranty & Support:

• Cisco standard hardware warranty (original purchases)
• Refurbished units typically include 30-day to 1-year warranty from resellers
• Limited or no Cisco TAC support for end-of-life products
• Third-party support services available from various providers

Why Choose the Cisco Catalyst WS-C3550-48-SMI:

The Catalyst 3550-48-SMI represented a breakthrough when introduced, bringing multilayer switching intelligence to the enterprise access layer at an attractive price point. With 48 Fast Ethernet ports, dual Gigabit uplinks supporting flexible GBIC modules, comprehensive Layer 3 routing (static and RIP), robust security with ACLs and 802.1X authentication, advanced QoS including Auto QoS for VoIP, and the ability to stack up to 9 switches or cluster up to 16 switches for simplified management, this switch delivered enterprise-class capabilities for medium-sized networks. While now an end-of-life product, refurbished units continue to provide reliable service in budget-conscious deployments, training labs, and environments where modern features are not required. The optional upgrade path to EMI software provided flexibility for organizations requiring advanced routing protocols, making the 3550 series a versatile platform that served thousands of organizations worldwide.