CISCO WS-C3550-48-SMI产品简介   cisco WS-C3550-48-SMI思科原装交换机
The Cisco Catalyst® 3550 Series Intelligent Ethernet Switches is a line of enterprise-class, stackable, multilayer switches that provide high availability, security and quality of service (QoS) to enhance the operation of the network. With a range of Fast Ethernet and Gigabit Ethernet configurations,cisco WS-C3550-48-SMI思科原装交换机 the Catalyst 3550 Series can serve as both a powerful access layer switch for medium enterprise wiring closets and as a backbone switch for small networks. Customers can deploy network-wide intelligent services, such as advanced QoS, cisco WS-C3550-48-SMI思科原装交换机rate-limiting, Cisco security access control lists, multicast management, and high-performance IP routing-while maintaining the simplicity of traditional local area network (LAN) switching. Embedded in the Catalyst 3550 Series is the Cisco cisco WS-C3550-48-SMI思科原装交换机 Cluster Management Suite (CMS) Software, which allows users to simultaneously configure and troubleshoot multiple Catalyst desktop switches using a standard Web browser. Cisco CMS Software provides new configuration wizards that greatly simplify the implementation cisco WS-C3550-48-SMI思科原装交换机 of converged networks and intelligent network services.
 
The Catalyst 3550-24 PWR switchcisco WS-C3550-48-SMI思科原装交换机 can provide a lower total cost of ownership for deployments that incorporate Cisco IP phones and/or Cisco Aironet wireless LAN access points. With up to 15 Watts of integrated inline power on every 10/100 port, the switch provides maximum device support and eases new technology deployments by eliminating the need for wall power to each IP phone or wireless LAN access point. Additionally, delivering power via the Catalyst 3550-24 PWR switch eliminates the cost for additional electrical cabling that would otherwise be necessary in wireless LAN and IP phone deployments. Maximum power availability for a converged voice and data network is attainable when a Catalyst 3550 Switch is combined with the Cisco Redundant Power System 675 (RPS 675) for seamless protection against internal power supply failures and an uninterruptable power supply (UPS) system to safeguard against power outages.
 
The Cisco Catalyst 3550 Series Intelligent Ethernet Switches include the following configurations:
cisco WS-C3550-48-SMI思科原装交换机 
• Catalyst 3550-24 Switch-24 10/100 ports and two Gigabit Interface Converter (GBIC)-based Gigabit Ethernet ports; 1 rack unit (RU)

 
• Catalyst 3550-24 PWR Switch-24 10/100 ports with integrated inline power and two GBIC-based Gigabit Ethernet ports; 1 RU

 
• Catalyst 3550-24-DC Switch-24 10/100 ports and two GBIC-based Gigabit Ethernet ports; 1 RU; DC-powered

 
• Catalyst 3550-24-FX Switch-24 100FX ports and two GBIC-based Gigabit Ethernet ports; 1 RU

cisco WS-C3550-48-SMI思科原装交换机 
• Catalyst 3550-48 Switch-48 10/100 ports and two GBIC-based Gigabit Ethernet ports; 1 RU

 
• Catalyst 3550-12G Switch-10 GBIC-based Gigabit Ethernet ports and two 10/100/1000BASE-T ports; 1.5 RU

 
• Catalyst 3550-12T Switch-10 10/100/1000BASE-T ports and two GBIC-based Gigabit Ethernet ports; 1.5 RU

cisco WS-C3550-48-SMI思科原装交换机 
The built-in Gigabit Ethernet ports accommodate a range of GBIC transceivers, including the Cisco GigaStack® GBIC, 1000BASE-T, 1000BASE-SX, 1000BASE-LX/LH, 1000BASE-ZX and CWDM GBICs. The dual GBIC-based Gigabit Ethernet implementation on the Fast Ethernet configurations provides customers tremendous deployment flexibility-allowing customers to implement one type of stacking and uplink configuration today, while preserving the option to migrate that configuration in the future. High levels of stack resiliency can also be implemented by deploying dual redundant Gigabit Ethernet uplinks, a redundant GigaStack GBIC loopback cable, UplinkFast and CrossStack UplinkFast technologies for high-speed uplink and stack interconnection failover, and Per VLAN Spanning Tree Plus (PVST+) for uplink load balancing. This Gigabit Ethernet flexibility makes the Catalyst 3550 switches an ideal LAN edge complement to the Cisco Catalyst 6500 family of Gigabit Ethernet optimized core LAN switches.
 cisco WS-C3550-48-SMI思科原装交换机
Included with the Catalyst 3550-24, 3550-24 PWR, 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 static and routed information protocol (RIP) routing functionality. The EMI provides a richer set of enterprise-class features including advanced hardware-based IP unicast and multicast routing and the Web Cache Communication Protocol (WCCP). After initial deployment, the EMI Upgrade Kit gives users the flexibility to upgrade to the EMI. The Catalyst 3550-12T and 3550-12G are only available with the EMI.
 
cisco WS-C3550-48-SMI思科原装交换机

 
INTELLIGENCE IN THE NETWORK

 
Networks of today are evolving to address four new developments at the network edge:
 
• Increase in desktop computing power

 
• Introduction of bandwidth-intensive applications

 
• Expansion of highly sensitive data on the network

 
• Presence of multiple device types, such as IP phones and wireless LAN access points These new demands are contending for resources with many existing mission-critical applications. As a result,

 
IT professionals must view the edge of the network as critical to effectively manage the delivery of information and applications.
 
As companies increasingly rely on networks as the strategic business infrastructure, it is more important than ever to ensure their high availability, security, scalability and control. By adding Cisco intelligent functionality to the wiring closet, customers can now deploy network-wide intelligent services that address these requirements in a consistent way from the desktop to the core and through the WAN.
 
With Cisco Catalyst Intelligent Ethernet switches, Cisco enables companies to realize the full benefits of adding intelligent services into their networks. Deploying capabilities that make the network infrastructure highly available to accommodate time-critical needs, scalable to accommodate growth, secure enough to protect confidential information, and capable of differentiating and controlling traffic flows are key to further optimizing network operations.
 
NETWORK CONTROL THROUGH ADVANCED QUALITY OF SERVICE AND RATE LIMITING

 
The Cisco Catalyst 3550 offers superior Layer 3 granular QoS features to ensure that network traffic is classified, prioritized, and congestion is avoided in the best possible manner. Configuration of QoS is greatly simplified through automatic QoS (Auto QoS), a feature that detects Cisco IP phones and automatically configures the switch for the appropriate classification and egress queuing. This optimizes traffic prioritization and network availability without the challenge of a complex configuration.
 
The Catalyst 3550 can classify, reclassify, police, and mark the incoming packets before the packet is placed in the 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 Catalyst 3550 switches identify traffic flows, or packet groups, and classifies or reclassifies these groups using the Differentiated Services Code Point field (DSCP) and/or the 802.1p class of service (CoS) field. 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 (TCP)/User Datagram Protocol (UDP) port. At the ingress, the Catalyst 3550 will also perform policing and marking of the packet. Control plane and data plane ACLs are supported on all ports to ensure proper policing and marking on a per packet basis.
 
After the packet goes through classification, policing, and marking, it is then assigned to the appropriate queue before exiting the switch. The Catalyst 3550 supports four egress queues per port, which allows the network administrator to be more discriminating and specific in assigning priorities for the various applications on the LAN. At egress, the switch performs scheduling and congestion control. Scheduling is an algorithm/process 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 algorithm ensures that the lower priority packets are not entirely starved for bandwidth and are serviced without compromising the priority settings administered by the network manager. Strict priority queuing ensures that the highest priority packets will always get serviced first, ahead of all other traffic, and allows the other three queues to be serviced using WRR scheduling. In conjunction with scheduling, the Catalyst 3550 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.
 
These features allow network administrators to prioritize mission-critical and/or bandwidth-intensive traffic, cisco WS-C3550-48-SMI思科原装交换机 such as Enterprise Resource Planning (ERP) (Oracle, SAP, etc.), voice (IP telephony traffic) and CAD/CAM over less time-sensitive applications such as FTP or e-mail (Simple Mail Transfer Protocol [SMTP]). For example, it would be highly undesirable to have a large file download destined to one port on a wiring closet switch and have quality implications such as increased latency in voice traffic, destined to another port on this switch. This condition is avoided by ensuring that voice traffic is properly classified and prioritized throughout the network. Other applications, such as Web browsing, can be treated as low priority and handled on a best-efforts basis.
 
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. Bandwidth allocation is essential in network environments requiring service-level agreements or when it is necessary for the network manager to control the bandwidth given to certain users. Each Catalyst 3550 switch 10/100 port supports 8 aggregate or individual ingress policers and 8 aggregate egress policers. cisco WS-C3550-48-SMI思科原装交换机 Each Catalyst 3550 Gigabit Ethernet port supports 128 aggregate or individual policers and 8 aggregate egress policers. This gives the network administrator very granular control of the LAN bandwidth.
 
NETWORK SCALABILITY THROUGH HIGH-PERFORMANCE IP ROUTING

 
With hardware-based IP routing and the Enhanced Multilayer Software Image, the Catalyst 3550 switches deliver high performance dynamic IP routing. The Cisco Express Forwarding (CEF)-based routing architecture allows for increased scalability and performance. This architecture allows for very high-speed lookups while also ensuring the stability and scalability necessary to meet the needs of future requirements. In addition to dynamic IP unicast routing, the Catalyst 3550 Series is perfectly equipped for networks requiring multicast support. Multicast routing protocol (PIM) and Internet Group Management Protocol (IGMP) snooping in hardware make the Catalyst 3550 Series switches ideal for intensive multicast environments.
 
These switches offer several advantages to improve network performance when used as a stackable wiring closet switch or as a top-of-the-stack wiring closet aggregator switch. For example, implementing routed uplinks from the top of the stack will improve network availability by enabling faster failover protection and simplifying the Spanning-Tree Protocol algorithm by terminating all Spanning-Tree Protocol instances at the aggregator switch. If one of the uplinks fails, quicker failover to the redundant uplink can be achieved via a scalable routing protocol such as Open Shortest Path First (OSPF) or Enhanced Interior Gateway Routing Protocol (EIGRP) rather than relying on standard Spanning-Tree Protocol convergence. Redirection of a packet after a link failure via a routing protocol results in faster failover than a solution that uses Layer 2 Spanning Tree enhancements. Additionally, routed uplinks allow better bandwidth utilization by implementing equal cost routing (ECR) on the uplinks to perform load balancing. This results in dynamic load balancing in a part of the network that often acts as the bottleneck. And, routed uplinks optimize the utility of uplinks out of the wiring closet by eliminating unnecessary broadcast data flows into the network backbone.
 
The Catalyst 3550 also offers dramatic bandwidth savings as a stackable wiring closet switch in a multicast environment. Using routed uplinks to the network core will eliminate the requirement to transmit multiple streams of the same multicast from the upstream content servers to the wiring closet. For example, if three users are assigned to three separate virtual LANs (VLANs) and they all want to view multicast ABC, then three streams of multicast ABC are required to be transmitted from the upstream router to the wiring closet switch-assuming the wiring closet switch is not capable of routed uplinks. Deploying IP routing to the core with Catalyst 3550 switches allows users to create a scalable, multicast- rich network.
 
NETWORK SECURITY THROUGH ENHANCED SECURITY FEATURES

 
The Cisco Catalyst 3550 Series switches offer enhanced data security through a wide range of security features that protect network management and administrative traffic, secure the network from unauthorized users, provide granular levels of network access to users, and track where users are located.
 
Secure Shell (SSH), Kerberos, and Simple Network Management Protocol version 3 (SNMPv3) encrypt administrative and network management information, thereby protecting it from tampering or eavesdropping. Terminal Access Controller Access Control System (TACACS+) or Remote Access Dial-In User Service (RADIUS) authentication enables centralized access control of switches and restricts unauthorized users from altering the configurations. Alternatively, a local username and password database can be configured on the switch itself. Fifteen levels of authorization on the switch console and two levels on the web-based management interface provide the ability to give different levels of configuration capabilities to different administrators.
 
Port security and 802.1x provide the ability to keep unauthorized users from accessing the network. Port security limits access on an Ethernet port based on the MAC address of the device that is connected to it. It can also be used to limit the total number of devices plugged into a switch port, thereby reducing the risks of rogue wireless access points or hubs. 802.1x can be used to authenticate users based on username and password (or other credentials) via a centralized RADIUS server. This is particularly useful for a mobile workforce because the authentication will be executed regardless of where the user connects to the network.
 
ACLs restrict access to sensitive portions of the network by denying packets based on source and destination MAC addresses, IP addresses, or TCP/UDP ports. ACL lookups are done in hardware; therefore, forwarding and routing performance is not compromised when implementing ACL-based security in the network. Catalyst 3550 Series switches offer VLAN, router and port-based ACLs. Deploying ACLs can be done through Cisco CMS Software Security Wizards, which in a few easy steps can restrict user access to a server, a portion of the network, or the usage of certain applications.
 
Identity-based Networking Services (IBNS) provide the ability to dynamically administer granular levels of network access. Leveraging the 802.1x standard and Cisco's Access Control Server (ACS), when users authenticate they can be assigned a VLAN and/or an ACL regardless of where they connect to the network. This functionality allows IT departments to enable strong security policies without compromising user mobility and with minimal administrative overhead.
 
The MAC Address Notification feature can be used to monitor the network and track users by sending an alert to a management station so that network administrators know when and where users entered the network. The Dynamic Host Configuration Protocol (DHCP) Interface Tracker (Option 82) feature tracks where a user is physically connected on a network by providing both switch and port ID to a DHCP Server.
 
VLANs ensure that data packets are forwarded only to stations within a specific subnet, creating a separate collision domain between groups of ports on the network and reducing broadcast transmission. VLAN trunks can be created from any port using the standards-based 802.1Q or Cisco Inter-Switch Link (ISL) VLAN trunking architecture. The Cisco Catalyst 3550 switches support up to 1,005 VLANs.
 
For even greater security between network end-stations, Private VLAN Edge isolates ports on a switch, ensuring that users cannot snoop on other users' traffic. Local Proxy Address Resolution Protocol (ARP) works in conjunction with private VLAN edge to minimize broadcasts and maximize available bandwidth.
 
NETWORK MANAGEMENT WITH THE CISCO CLUSTER MANAGEMENT SUITE SOFTWARE

 
The Cisco CMS is Web-based software that is embedded in Catalyst 3550, 2950, 3500 XL, 2900 XL, 2900 LRE XL, and 1900 switches. Through Cisco Switch Clustering technology, users access Cisco CMS with any standard Web browser to manage up to 16 of these switches at once, regardless of their physical proximity-with the option of using a single IP address for the entire cluster if desired. With the addition of the Catalyst 3550 switches, Cisco CMS Software can now extend beyond routed boundaries for even more flexibility in managing a Cisco cluster.
 
Cisco CMS provides an integrated management interface for delivering intelligent services, such as multilayer switching, QoS, multicast, and security ACLs. Thus, Cisco CMS allows administrators to take advantage of benefits formerly reserved for only the most advanced networks without having to learn the command-line interface (CLI) or even the details of the technology.
 
The new Guide Mode in Cisco CMS leads the user step-by-step through the configuration of high-end features and provides enhanced online help for context-sensitive assistance. In addition, Cisco AVVID (Architecture for Voice, Video and Integrated Data) Wizards provide automated configuration of the switch to optimally support video streaming or videoconferencing, voice over IP (VoIP), and mission-critical applications. Additional wizards for LAN security and multicast traffic are available too. These Wizards can save hours of time for network administrators, eliminate human errors, and ensure the configuration of the switch is optimized for these applications.
 
Because Cisco Switch Clustering technology is not limited to a single stack of switches, Cisco CMS expands the traditional cluster domain beyond a single wiring closet and saves time and effort for network administrators. The switches must merely be connected to each other via Ethernet, Fast Ethernet, Fast EtherChannel®, Gigabit Ethernet, Gigabit EtherChannel, and/or GigaStack connectivity.
 
Cisco Catalyst 3550 switches can be configured either as command or member switches in a Cisco switch cluster. Cisco CMS also allows the network administrator to designate a standby or redundant command switch, which takes the commander duties should the primary command switch fail. Other key features include the ability to configure multiple ports and switches simultaneously, perform software updates across the entire cluster at once, and clone configurations to other clustered switches for rapid network deployments. Bandwidth graphs and link reports provide useful diagnostic information and the topology map gives network administrators a quick view of the network status.
 
In addition to Cisco CMS, the Catalyst 3550 products are manageable via CiscoWorks products, which provide full enterprise-class network management. CiscoWorks Resource Manager Essentials (RME) can be used to perform network-wide software upgrades, configuration file audits, configuration file distribution, and inventory reports. Additional tools include the Campus Manager, CiscoView, Device Fault Manager (DFM), QoS Policy Manager (QPM), User Registration Tool, and many others. For smaller networks, CiscoWorks Small Network Management Solution (SNMS) provides advanced network management capabilities to reduce IT administrative overhead.