Cisco2960
Cisco 2960 Ethernet Switches
        The Cisco Catalyst 2960 LAN Base Series offers superior multilayer QoS features to help ensure that network traffic is classified and prioritized and that 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 Cisco Catalyst 2960 LAN Base Series can classify, reclassify, police, mark, queue, and schedule incoming packets and can queue and schedule packets at egress. 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, the Cisco Catalyst 2960 LAN Base Series Switch first identifies traffic flows or packet groups, then classifies or reclassifies these groups using the differentiated services code point (DSCP) field or the 802.1p class of service (CoS) field. Classification and reclassification can be based on criteria as specific as the source or destination IP address, source or destination MAC address, or the Layer 4 TCP or UDP port. At the ingress, the Cisco Catalyst 2960 LAN Base Series also polices to determine whether a packet is in or out of profile, marks to change the classification label, passes through or drops out of profile packets, and queues packets based on classification. Control-plane and data-plane ACLs are supported on all ports to help ensure proper treatment on a per-packet basis.
        The Cisco Catalyst 2960 LAN Base Series supports four egress queues per port, giving network administrators more control in assigning priorities for the various applications on the LAN. At egress, the switch performs congestion control and scheduling, the algorithm or process that determines the order in which queues are processed. The Cisco Catalyst 2960 LAN Base Series Switch supports Shaped Round Robin (SRR) and strict priority queuing. The SRR algorithm helps ensure differential prioritization.
        These QoS features allow network administrators to prioritize mission-critical and bandwidth-intensive traffic, such as enterprise resource planning (ERP), voice (IP telephony traffic), and computer-aided design and manufacturing (CAD/CAM), over applications such as FTP or e-mail. For example, it would be undesirable to have a large file download destined to one port on a switch increase latency in voice traffic destined to another port on this switch. This condition is avoided by making sure that voice traffic is properly classified and prioritized throughout the network. Other applications, such as Web browsing, can be handled on a lower-priority basis.
        The Cisco Catalyst 2960 Series LAN Base can perform rate limiting through its support of the Cisco committed information rate (CIR) function. Through CIR, bandwidth can be guaranteed in increments as small as 1 Mbps. Bandwidth can be allocated based on several criteria, including MAC source address, MAC destination address, IP source address, IP destination address, and TCP or UDP port number. Bandwidth allocation is essential when network environments require service-level agreements or when it is necessary to control the bandwidth given to certain users.

Advanced QoS
• Standard 802.1p CoS and DSCP field classification are provided, using marking and reclassification on a per-packet basis by source and destination IP address, source and destination MAC address, or Layer 4 TCP or UDP port number.
• Cisco control-plane and data-plane QoS ACLs on all ports help ensure proper marking on a per-packet basis.
• Four egress queues per port enable differentiated management of up to four traffic types.
• SRR scheduling ensures differential prioritization of packet flows by intelligently servicing the ingress and egress queues.
• Weighted tail drop (WTD) provides congestion avoidance at the ingress and egress queues before a disruption occurs.
• Strict priority queuing guarantees that the highest-priority packets are serviced ahead of all other traffic.
• There is no performance penalty for highly granular QoS functions.

Granular Rate Limiting
• The Cisco CIR function guarantees bandwidth in increments as small as 1 Mbps.
• Rate limiting is provided based on source and destination IP address, source and destination MAC address, Layer 4 TCP and UDP information, or any combination of these fields, using QoS ACLs (IP ACLs or MAC ACLs), class maps, and policy maps.
• Asynchronous data flows upstream and downstream from the end station or on the uplink are easily managed using ingress policing and egress shaping.
• Up to 64 aggregate or individual polices are available per Fast Ethernet or Gigabit Ethernet port.