New features, support and services boost network management appeal
- By J.B. Miles
- Oct 03, 2002
As administrators optimize their networks for top performance, switch makers are adding built-in or optional advanced features to make their products more attractive to a wider range of buyers.
You might not need all these features, but you should be aware of them.
Generally, they include port trunking, VLAN support, traffic prioritization and class of service, advanced SNMP/RMON management tools and multicasting, according to John Pappas, director of technical marketing at Enterasys Networks Inc.Port trunking.
Port trunking increases bandwidth by the number of links combined. For example, combining three 100-Mbps connections via port trunking results in a 300-Mbps capacity. Port trunking also provides redundancy, meaning if one of the combined links fails, the remaining links will continue to function and share traffic.VLAN support.
A virtual LAN, or VLAN, is a collection of PCs, workstations, servers and peripherals grouped in a logical, but not necessarily a physical, domain. A switch's support for VLANs lets organizations group their workgroups according to responsibilities, regardless of where the people are.Traffic prioritization and class of service.
Traffic prioritization gives preferential treatment to special classes of data selected by network administrators. End-to-end class of service can only be accomplished if all the devices on the network can support it, so it remains more a goal than a fact, except in very expensive systems.Spanning tree support.
If redundant paths exist on an Ethernet network, they create broadcast loops whereby all packets broadcast around the network are flooded back to the sending switch. Support for the spanning tree protocol protects against network loops and provides redundant network paths.SNMP/RMON.
Advanced SNMP and RMON protocols add more sophisticated management layers than basic protocol sets.
<> The Internet Group Multicast Protocol (IGMP) paves the way for the broadcasting of voice, video and data over the Internet and corporate intranets. IP multicasting transmits IP packets from one source to many destinations on the network, but the network forwards packets only to the hosts that need them. If the switch supports multicasting, a packet for multiple recipients can be sent as a single packet instead of as many copies of the same packet.