3com 3C17701 Specification Guide

3 C O M

S U P E R S TA C K

3 S W I T C H 4 9 0 0 FA M I LY D ATA S H E E T

Features

PERFORMANCE

Switching Capacity

32Gbps for SuperStack 3 Switch 4900 and 4900 SX; 56Gbps for SuperStack 3 Switch 4924 and 4950

Forwarding Rate

23.8Mpps for SuperStack 3 Switch 4900 and 4900 SX; 41.6Mpps for SuperStack 3 Switch 4924 and 4950

Store and Forward Switching

Latency 2.7 microseconds for all models

LAYER 2 SWITCHING

MAC Addresses

12K MAC addresses

VLAN

30 VLANs (IEEE 802.1Q)

Link Aggregation

Manual and LACP Link Aggregation (IEEE 802.3ad). 13 groups/4 ports in each

Auto Negotiation

Auto-negotiation of port speed, duplex, and connection (MDI/MDIX)

Traffic Control

IEEE 802.3x full-duplex flow control

Back pressure flow control for half-duplex

Supports Broadcast Storm Suppression

Spanning Tree

IEEE 802.1D Spanning Tree Protocol (STP)

IEEE 802.1w Rapid Spanning Tree Protocol (RSTP), backward-compatible with STP

Fast-start mode

Spanning tree enable/disable per port or per VLAN

LAYER 3 SWITCHING

Routes

Hardware-based routing

2,000 IP routes

100 Static Routes

5,000 ARP entries

64 IP interfaces

IP Routing

IP Multinetting (multiple IP interfaces per VLAN)

CIDR (Classless Internet Domain Routing)

RIP (Routing Information Protocol), v1 and v2

OSPF (Open Shortest Path First)

• 4 areas with 64 adjacencies

• ASBR support for static and default routes

Multicast

Filtering for 128 multicast groups

IGMP (Internet Group Management Protocol) snooping on Layer 2 interfaces

IGMP v1 and v2

IGMP Querier

Network Protocol

DHCP Relay (Dynamic Host Configuration Protocol Relay)

UDP (User Datagram Protocol) Helper

ARP (Address Resolution Protocol)

Access Control Lists

VLAN-based ACLs

• Filtered on destination IP address / mask

CONVERGENCE

Priority Queues

Four hardware queues per port

Weighted Round Robin queuing

Traffic Prioritization

Priority based on:

• IP address

• IEEE 802.1p Class of Service (CoS) VLAN priority

• TCP/UDP destination port number

• DSCP (DiffServ Code Point)

• Ethertype

• Default port priority

• Auto classification of 3Com NBX

telephony traffic

* Only available on SuperStack 3 Switch 4924 and 4950 models.