Carrier Access 3750 Series manual FeatureBenefit, QoS/Control

Table 1 Product Features and Benefits

FeatureBenefit

Integrated Cisco IOS Software features for bandwidth optimization

•Per-port broadcast, multicast, and unicast storm control prevents faulty end stations from degrading overall systems performance.

•Web Cache Communication Protocol (WCCP) allows interaction with a Web cache for the purpose of redirecting content requests and performing basic load balancing across multiple caches. EMI is required.

•IEEE 802.1d Spanning Tree Protocol support for redundant backbone connections and loop-free networks simplifies network configuration and improves fault tolerance.

•PVST+ allows for Layer 2 load sharing on redundant links to efficiently utilize the extra capacity inherent in a redundant design.

•IEEE 802.1s Multiple Spanning Tree Protocol (MSTP) allows a spanning-tree instance per VLAN, enabling Layer 2 load sharing on redundant links.

•Equal-cost routing for Layer 3 load balancing and redundancy across the stack. EMI is required.

•Local Proxy Address Resolution Protocol (ARP) works in conjunction with Private VLAN Edge to minimize broadcasts and maximize available bandwidth.

•VLAN1 minimization allows VLAN1 to be disabled on any individual VLAN trunk link.

•VLAN Trunking Protocol (VTP) pruning limits bandwidth consumption on VTP trunks by flooding broadcast traffic only on trunk links required to reach the destination devices.

•Internet Group Management Protocol (IGMP) snooping provides fast client joins and leaves of multicast streams and limits bandwidth-intensive video traffic to only the requestors.

•Multicast VLAN Registration (MVR) continuously sends multicast streams in a multicast VLAN while isolating the streams from subscriber VLANs for bandwidth and security reasons.

•Up to 12 EtherChannel groups are supported per stack.

Scalable stacking	• Cisco StackWise stacking creates a 32-Gbps backplane. Stacking does not require
	user ports. Up to 9 units can be stacked together for a maximum of 468 10/100
	ports, 252 10/100/1000 ports, 108 optical aggregation ports, or any mix thereof.
QoS/Control
Advanced QoS	• Cross-stack QoS allows QoS to be configured across the entire stack.
	• 802.1p class of service (CoS) and Differentiated Services Code Point (DSCP) field
	classification are provided, using marking and reclassification on a per-packet
	basis by source and destination IP address, source and destination Media Access
	Control (MAC) address, or Layer 4 Transmission Control Protocol/User Datagram
	Protocol (TCP/UDP) port number.
	• Cisco control-plane and data-plane QoS ACLs on all ports ensure proper marking
	on a per-packet basis.
	• 4 egress queues per port enable differentiated management of up to 4 traffic
	types across the stack.
	• Shaped Round Robin (SRR) scheduling ensures differential prioritization of packet
	flows by intelligently servicing the ingress queues 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 functionality.

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