Cisco Catalyst 3550, Catalyst 3550-24, Catalyst 3550-48, Catalyst 3550 Series Datasheet

Cisco Catalyst 3550 Series

Intelligent Ethernet Switches for Metro Access

Data Sheet

Product Overview

The Cisco Catalyst®3550 Series Intelligent
Ethernet switches is a line of powerful,
fixed-configurationmultilayerswitchesthat
extendintelligence to themetro accessedge,
enabling service breadth, availability,
security,andmanageability .Keycomponents
of the Cisco Metro Ethernet Switching
portfolio,theseswitches are idealforservice
providers looking to deliver profitable
Ethernet services while minimizing total
cost of ownership. With a range of Fast
Ethernet, Gigabit Ethernet, DC power, and
fiber configurations, the Cisco Catalyst
3550 Series is the ideal metro access switch
for enterprise and small and medium-sized
business markets. Featuring 802.1Q
tunneling, high-performance IP routing,
and subsecond Spanning-Tree Protocol
(STP) convergence, this line of powerful,
yet cost-effective, fixed-configuration
switches enable a variety of metro services,
such as transparent LAN services and
business-class Internet access.

The Cisco Catalyst 3550 Series Intelligent
Ethernet switches include the following
configurations:

• Cisco Catalyst 3550-24 Switch—
24 10/100portsand 2 Gigabit Interface
Converter (GBIC)-based Gigabit
Ethernet ports; 1 rack unit (RU)

• Cisco Catalyst 3550-24-DC Switch—
24 10/100 ports and 2 gigabit interface
converter (GBIC)-based Gigabit
Ethernet ports; 1 RU DC-powered

• Cisco Catalyst 3550-24-FX Switch—
24 100FX multimode fiber ports and
2 GBIC-based Gigabit Ethernet
ports; 1 RU

• Cisco Catalyst 3550-48 Switch—
48 10/100 ports and 2 GBIC-based
Gigabit Ethernet ports; 1 RU

• Cisco Catalyst 3550-12G Switch—
10 GBIC-based Gigabit Ethernet ports
and 2 10/100/1000BaseT ports; 1.5 RU

• Cisco Catalyst 3550-12T Switch—
10 10/100/1000BaseT ports and
2 GBIC-based Gigabit Ethernet
ports; 1.5 RU

The built-in Gigabit Ethernet ports
accommodatea rangeof GBICtransceivers,
including the Cisco Course Wave Division
Multiplexing (CWDM) GBIC Solution,

®

GigaStack
1000BaseSX, 1000BaseLX/LH, and
1000BaseZX GBICs. High levels of
resiliency can also be implemented by
deploying dual redundant Gigabit Ethernet
uplinks, UplinkFast and Per-VLAN
SpanningTree Plus(PVST+) for uplinkload
balancing. This Gigabit Ethernet flexibility
makes the Cisco Catalyst 3550 Series
switches an ideal metro access edge
complement to the Cisco 7600 Series
Internet Router and Cisco Catalyst 6500
Series of metro Ethernet switches.

GBIC, 1000BaseT,

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Included with the Cisco Catalyst 3550-24, 3550-24-DC, 3550-24-FX and 3550-48 are the Standard Multilayer
Software Image (SMI) or the Enhanced Multilayer Software Image (EMI). The SMI feature set includes advanced
QoS, rate-limiting, access control lists (ACLs), and basic state and RIP routing functionality. The EMI provides a
richer set of features including advanced hardware-based IP unicast and multicast routing and the Web Cache
Communication Protocol (WCCP). After initial deployment, the Enhanced Multilayer Software Image Upgrade Kit
gives userstheflexibility to upgrade to the EMI.TheCisco Catalyst 3550-12T and 3550-12G areonlyavailable with
the EMI.

Figure 1

Cisco Catalyst 3550-24 Intelligent Ethernet Switch

Figure 2

Cisco Catalyst 3550-24-DC Intelligent Ethernet Switch

Figure 3

Cisco Catalyst 3550-24-FX Intelligent Ethernet Switch

Figure 4

Cisco Catalyst 3550-48 Intelligent Ethernet Switch

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Figure 5

Cisco Catalyst 3550-12G and 3550-12T Intelligent Ethernet Switches

Intelligence at the Metro Access Edge: Enabling Profitable Ethernet Services

Service providers are facing significant challenges in meeting the service needs of their enterprise and small and
medium-sized business (SMB) market customers. As they continue to put more and more mission-critical
applications on their networks, these customers are demanding high bandwidth at speeds greater than T1/E1 and at
competitive prices. Enterprise and SMB customers have experienced the speed and cost benefits of Ethernet in their
LANs and want to extend these benefits into the wide-area and metro-area networks (WAN and MAN). However,
in today’s economic environment, service providers face several challenges as they look to meet the service needs of
their customers. Such challenges include:

• Providing profitable new services while reducing operational and capital costs

• Meeting variable bandwidth demand at speeds greater than T1/E1

• Effectively integrating existing WAN services such as Frame Relay and Asynchronous Transfer Mode (ATM)

• Building cost-effective, highly available, scalable metro Ethernet networks

These challenges are especially evident at the metro access edge. As service providers look to provide profitable
Ethernet services such as Layer 2 virtual private networks (Layer 2 VPNs) or business Internet access, Cisco
intelligent functionality such as 802.1Q tunneling, advanced quality of service (QoS), and granular rate-limiting, is
essentialinthe serviceprovider’s customerlocated equipment. Inaddition, with intelligentfeatures such assubsecond
STP convergence and CWDM GBIC support, Cisco Catalyst 3550 Series switches provide the necessary network
availability and scalability at the access edge. With Cisco Catalyst 3550 Series Intelligent Ethernet switches, Cisco
delivers the optimal balance of performance, cost-effectiveness, and intelligence, enabling profitable Ethernet service
breadth, availability, security, and manageability.

Most important,theCiscoCatalyst 3550 Series is a key componentofthe Cisco Metro Ethernet Switching portfolio.
For regional metro, metro aggregation and metro access, Cisco Metro Ethernet Switching enables service providers
to deliver profitable, comprehensive Ethernet services. With the effective integration of existing WAN services, such
as Frame Relay and ATM, Cisco Metro Ethernet Switching offers an unmatched breadth of service delivery
mechanisms. Withits extensive automated operations support, Cisco also helps serviceprovidersminimize total cost
of ownership for new services. Through technology leadership, financial stability, and a commitment to customer
support, Cisco ensures service success from “start-to-scale.”

Service Breadth through 802.1Q Tunneling, Advanced Quality of Service, and Rate-limiting

The Cisco Catalyst 3550, with its 802.1Q tunneling capability, enables service providers to create Layer 2
transparent LAN services (TLS) with a clear separation of their network from enterprise and SMB customer
networks. Using a 802.1Q tunneling implementation, service provider VLAN information (802.1Q tag) is added to
the customer’s original 802.1Q-tagged packets as the packets come into the service provider network. The service

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provider 802.1Q tag is removed when the packets exit their network, leaving the original packets untouched. Other
Layer 2 protocols such as STP, VLAN Trunk Protocol (VTP), and Cisco Discovery Protocol will also be tunneled
through theservice provider’snetwork. The 802.1Q tunnelingfeature enables service providerstouse a single VLAN
(up to 4096 VLAN IDs) to support customers who have multiple VLANs. In addition, the feature preserves
customers’ original VLAN IDs and segregates traffic from different customers within the service provider
infrastructure even when those customers use the same VLAN IDs. As a result, enterprise customers subscribing to
TLS cantransparentlysend and receive traffic from othermetrosites through the service provider networkasthough
the sites were within the same corporate LAN.

In addition to Layer 2 VPN services, Multi-VRF CE (Virtual Routing Forwarding Customer Edge, also called
VRF-lite) and Border Gateway Protocol (BGP) on the Cisco Catalyst 3550 will enable thecreationofaLayer3VPN
service by keeping separate routing tables for each VPN customer. Multi-VRF CE is a feature that allows a service
provider to support two or more VPNs on a single 3550 switch, where IP addresses can be overlapped among the
VPNs. Multi-VRF CE uses input interfaces to distinguish routes for different VPNs and forms virtual
packet-forwarding tables by associating one or more Layer 3 interfaces with each VRF. Interfaces in a VRF can be
either physical, such as Ethernet ports, or logical, such as VLAN SVIs, but an interface cannot belong to more than
one VRF at any time.

The Cisco Catalyst 3550 offers superior Layer 3 granular QoS features to enable service providers to provide high­quality services with service-level agreements (SLAs). The QoS features ensure that network traffic is classified,
prioritized, and congestion is avoided in the most efficient manner possible. The Cisco Catalyst 3550 can classify,
reclassify, police, andmark the incoming packets beforethe packet is placed inthe shared buffer. Packet classification
allows the network elements to discriminate between various traffic flows and enforce policies based on Layer 2 and
Layer 3 QoS fields.

To implement QoS, first, the Cisco Catalyst 3550 switches identify traffic flows, or packet groups, and classify or
reclassify these groups using either the Differentiated Services Code Point (DSCP) field or the 802.1p class-of-service
(CoS) field, or both. Classification and reclassification can be based on criteria as specific as the source/destination
IP address, source/destination Media Access Control (MAC) address, or the Layer 4 Transmission Control Protocol/
User Datagram Protocol (TCP/UDP) port. At the ingress, the Cisco Catalyst 3550 can also perform policing and
marking of the packet. To ensure proper policing and marking on a per packet basis, control plane and data plane
access control lists (ACLs) are supported on all ports.

After the packet goes through classification, policing, and marking, it is assigned to the appropriate queue before
exiting the switch. The Cisco Catalyst 3550 Series supports four egress queues per port, which allows the service
provider to be more discriminating and specific in assigning priorities for the various applications. At egress, the
switch performs scheduling and congestion control. Scheduling is an algorithm that determines the order in which
the queues are processed. The switches support Weighted Round Robin (WRR) scheduling and strict priority
queuing. The WRR queuing algorithmensuresthatthe lower-priority packets are not entirely starved forbandwidth
and are serviced without compromising the priority settings administered by the service provider. Strict priority
queuing ensuresthat the highest-priority packets will alwaysget serviced first, ahead ofallother traffic, which allows
theotherthree queues to beserviced using WRR scheduling.Inconjunction with scheduling, theCisco Catalyst 3550
Series Gigabit Ethernet ports support congestion control via Weighted Random Early Detection (WRED). WRED
avoids congestion by setting thresholds at which packets are dropped before congestion occurs.

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The Cisco Catalyst 3550 is capable of performing rate limiting via its support of the Cisco Committed Information
Rate (CIR) functionality. Through CIR, bandwidth can be guaranteed in increments as low as 8 Kbps. Bandwidth
can be allocated based on several criteria, including MAC source address, MAC destination address, IP source
address, IP destination address, and TCP/UDP port number. Per-VLAN, per-port policing on the ingress is also
supported. Each Cisco Catalyst 3550 Series 10/100 port supports eight aggregate or individual ingress policers and
eight aggregate egress policers. Each Cisco Catalyst 3550 Series Gigabit Ethernet port supports 128 aggregate or
individual ingress policers and 8 aggregate egress policers. This gives service providers the flexibility to offer more
granular services.

In addition,the Cisco Catalyst 3550Seriesalso supports hardware-based high-performanceIProuting, such as Open
Shortest Path First (OSPF); Interior Gateway Routing Protocol (IGRP); Enhanced IGRP (EIRGP); Border Gateway
Protocol (BGP); Routing Information Protocol (RIP) and RIP v2; Protocol-Independent Multicast (PIM); and
hardware-based IGMP snooping for multicast applications. For voice over IP (VoIP),the Cisco Catalyst 3550 Series
supports Auxiliary VLAN. Together with the superior QoS and rate-limiting features mentioned above, service
providers can build a flexible network with the Cisco Catalyst 3550 Series to provide voice, video, and high-speed
data services from a single network architecture.

Service Availability through Resiliency Enhancements and Network Redundancy

The Cisco Catalyst 3550 Series provides a rich set of resiliency enhancement features to ensure quick fail-over
recovery and create a high-availability network. The IEEE 802.1w Rapid Spanning Tree standard allows the service
provider to achieve subsecond spanning tree convergence times to maximize network stability and reliability. The
IEEE802.1sMultiple Spanning Treestandard can bedeployed in conjunction with802.1wto improve thescalability
of the STP by grouping VLANs into spanning tree instances, as well as by providing backward compatibility to
devices running the 802.1D STP.

In addition, service providers can enable Bridge Protocol Data Unit (BPDU) guard and Spanning Tree Root Guard
(STRG) to enhance the reliability of their networks. BPDU guard allows the service provider to shut down STP
PortFast-enabled interfaces to avoid receiving BPDUs from their customers’ networks. STRG prevents customer
devices outside the service provider’s network from becoming STP root nodes.

The Cisco Catalyst 3550 Series enables the service provider to construct a highly redundant network. Per-VLAN
Spanning Tree Plus (PVST+) allows the service provider to implement Layer 2 load-sharing on redundant links,
efficiently utilizing the extra capacity inherent in a redundant design. For a Layer 3 network, Cisco Hot Standby
Router Protocol (HSRP) creates redundant fail-safe routing topologies, and equal-cost routing provides Layer 3

®

load-balancing and redundancy. Service providers can also utilize EtherChannel

technology to aggregate up to
16 Gbps through Gigabit EtherChannel and up to 1.6 Gbps through Fast EtherChannel. The EtherChannel
technology enhances fault tolerance and offers higher speed aggregated bandwidth between switches and to routers.

In addition to resiliency andnetworkredundancyadvantages, the Cisco Catalyst 3550 Series enables metro network
scalability at the access edge through its support of the Cisco CWDM GBIC Solution. This solution allows service
providers to scale their bandwidth without deploying additional fiber. The service provider can scale up to eight
Gigabitsofbandwidth on apair of single-mode fibersat distances upto120 km. Withthe support forCWDM GBICs
on the Cisco Catalyst 3550 Series, service providers can aggregate multiple Cisco Catalyst 3550 switches to easily
upgrade network bandwidth with existing fiber infrastructure.

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Metro network scalability isalsoenhancedby the Cisco Catalyst 3550 Series support of 4,096 VLAN IDs and 1,005
active VLANsperswitch. VLAN trunks can becreatedfrom any port using thestandards-based802.1Q or the Cisco
Inter-Switch Link (ISL) VLAN trunking architecture.

Service Security through Access Control Lists and Enhanced Security Features

The Cisco Catalyst 3550 Series offers enhanced data security through the use of access control lists (ACLs). By
denying packets based on source and destination MAC addresses, IP addresses, or TCP/UDP ports, users can be
restricted from sensitive portions of the network. Also, because all ACL lookups are done in hardware, forwarding
and routing performance is not compromised when implementing ACL-based security in the network. For superior
security management, the Cisco Catalyst 3550 Series supports standard and extended ACLs on VLANs, Layer 3
interfaces, as well as Layer 2 interfaces.

Service providers can also implement higher levels of security by enabling private VLAN edge. This feature provides
security and isolation between ports on a switch, ensuring that traffic travels directly from its entry point to the
aggregation devicethrougha virtual path and cannot be directed toadifferent port. Local Proxy Address Resolution
Protocol (ARP) works in conjunction with private VLAN edge to minimize broadcasts and maximize
available bandwidth.

Withthe Cisco Catalyst3550Series, service providerscan implement highlevelsof console security.Multilevelaccess
security on the switch console and the Web-based management interface prevents unauthorized users from accessing
or altering switch configuration. Terminal Access Controller Access Control System (TACACS+) and Remote
Authentication Dial-In User Service (RADIUS) authentication enable centralized access control of the switch and
restricts unauthorized users from altering the configuration.

Service providers are also able to enhance their network security by adding 802.1x port-based authentication for
authenticating individual customers, DHCP Interface Tracker (Option 82) for relaying customer identification
(switch and port ID) to a DHCP server,andport security with MAC address aging for limiting the concurrent MAC
addresses allowed per port.

Service Management through IE 2100 and SNMP

The Cisco Catalyst 3550 Series provides outstanding service management capabilities via Cisco IE 2100 Series
Intelligence Engine support and SNMP. Service providers will be able to integrate the Cisco Catalyst 3550 Series
seamlessly into their operations support systems (OSSs) and enable improved flow-through provisioning.

The Cisco IE 2100 Series network device allows service providers to effectively manage a network of Cisco IOS

®

Software devices, including the Cisco Catalyst 3550 Series. It is a completely self-contained unit that includes a
task-oriented Web graphic user interface (GUI), a programmable extensible markup language (XML) interface,
configuration template management, and an embedded repository. Network operators can use the Web GUI to
quickly turn existing Cisco IOS CLI configuration files into reusable templates. The Cisco IE 2100 Series integrates
easily into existing customer OSSs or business support systems (BSSs) and provisioning systems via its external
repository support and the event-based Cisco IOS XML interface that effectively “workflow-enables” Cisco
device deployment.

Service providers also can manage the Cisco Catalyst 3550 Series using Simple Network Management Protocol
(SNMP) version 2 and version 3, and the Telnet interface for comprehensive in-band management. A CLI-based
management console provides detailed out-of-band management.

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