Layer 2 switches

Layer 2 switches<@VM>Affordable Layer 2 switches deliver data fast<@VM>Affordable Layer 2 switches deliver data fast (cont.)

Cost-effective traffic controls can bring your LAN up to speed

By J.B. Miles

Special to GCN

If your legacy Ethernet LANs are stretched to the breaking point under the weight of new users, servers and high-end applications, try replacing old Ethernet hubs with one or more 10/100-Mbps Ethernet switches.


Garrett Communications' Magnum switches come with eight to 24 10/100-Mbps ports and range in price from $599 to $1,199.


All the switches in this guide are reasonably priced, flexible and suitable for running small networks or for connecting many small workgroups at larger sites. Unmanaged eight- or 16-port switches sell for as little as $20 per port, and many managed 16- or 24-port switches sell for as low as $100 per port.

Unlike hubs, which share available bandwidth among attached devices, nonblocking switches provide dedicated 10- or 100-Mbps bandwidth to networked PCs, workstations and servers. And if you can't yet part with your existing hubs, you can use 10/100 switches to connect them for better network segmentation.

At the desktop, 10/100 switches are the best possible devices for connecting multiple users to the network at top speeds.

The accompanying chart lists 66 10/100 dual Ethernet workgroup switches from 26 manufacturers. They are equipped with eight, 16 or 24 auto-sensing 10/100 ports to determine the speed of attached devices and automatically configure the ports for 10-Mbps or 100-Mbps throughput. All can automatically negotiate between half- and full-duplex modes'the latter effectively creating dedicated 20-Mbps or 200-Mbps connections.

Most switches listed also provide shared or dedicated 10/100 uplinks to other switches or network backbones, and some even provide one or two dedicated Gigabit Ethernet links for especially heavy bandwidth requirements.


Hewlett-Packard's ProCurve Switch 408 is an unmanaged, eight-port switch in a rackmount design. It is priced at $229.


The products in this guide are Layer 2 switches, meaning they operate at the second, or data link, layer of the Open Systems Interconnection model. Their function is to check incoming network traffic, keep track of the physical addresses of all stations attached to their ports and forward traffic to specific station addresses according to the forwarding tables they have built. Layer 2 switches can deliver data at wire speeds because they don't have to examine individual data packets.

Layer 3 switches, also called routing or IP switches, perform both switching and routing tasks. Because they make heavy use of integrated circuits, specialized crossbar switching fabric, fast CPUs and other high-end components, they are expensive but well-suited to network backbone service.

But less expensive Layer 2 switches also provide an extensive range of features and options, making them cost-effective for managing traffic at the workgroup and small network levels.

Among their features and characteristics are:

Auto-sensing. A switch's auto-sensing capability means it can determine the speed of attached devices and automatically configure the ports for 10-Mbps or 100-Mbps throughput. It does this by reading the speed of the network adapter or network interface card attached to the networked PC or server.


Tips for buyers
•Choose the right path: Dual-speed 10/100-Mbps switches are the best hardware for migrating from Ethernet to Fast Ethernet.

•Remember that switches with one or more dedicated uplinks provide better expansion paths than those with shared-port uplinks.

•Consider a vendor with a large family of switch products if you know you'll be expanding your networks again.

•Buy a managed switch if you need to monitor and report on hubs, bridges, routers and other switches on the network.

•Plan carefully before making network moves and changes.


Auto-negotiation. A switch's ability to automatically negotiate between half- and full-duplex modes is extremely useful for particularly bandwidth-hungry client applications, such as a remote computer-aided design and manufacturing workstation.

Full-duplex Fast Ethernet mode temporarily shuts down the Ethernet carrier-sense multiple-access with collision detection and loopback functions, allowing the switch to provide a theoretical bandwidth of 200 Mbps; that is, 100 Mbps in each direction.

But this capability comes at the expense of some of the collision detection features of half-duplex mode and should be only be used for isolated high-speed workstations where collision detection isn't required.

Top aggregate bandwidth. Aggregate bandwidth is the top theoretical speed limit of each switch and is related to the number of ports employed. Thus, the aggregate bandwidth of an eight-port switch running at 100 Mbps per port is 800 Mbps, while it's 1.6 Gbps for a 16-port switch.

Store-and-forward. The simplest switches operate as cut-through devices, meaning they only examine a packet's destination before forwarding it. More advanced store-and-forward switches analyze the entire packet before forwarding it. The tradeoff? Store-and-forwarding eliminates many traffic errors but takes longer than the cut-through technique.

Unmanaged. Workgroup switches may be managed or unmanaged. Unmanaged switches are plug-and-play devices and are a good match for small, flat networks with a mixture of 10-Mbps and 100-Mbps legacy devices. They can automatically learn network addresses and can handle both auto-sensing and auto-negotiation.

The best thing about them is their price. 3Com Corp.'s OfficeConnect Dual Speed Switch 8 is priced at $210, and Accton Technology Corp.'s popular CheetahSwitch Workgroup 3008A has been reduced to $199. D-Link Systems Inc.'s DSS-8+ can be bought for as low as $87 from third-party vendors, and ARK Technologies' $75 CT2208D unmanaged switch is the cheapest I've seen'less than $10 per port.

Managed. Managed switches, in the $1,000 and up price range, are more expensive because they perform more services. Network management features are important when remote switch management is required, or when several switches are linked as part of a more complex network than a LAN.

Products such as Allied Telesyn International Corp.'s $1,369, 16-port AT-8118 and all of Cisco Systems Inc.'s Catalyst 2900XL models'priced at $964 and up'come with proprietary management software. The software most often combines Simple Network Management Protocol and Remote Monitoring network management standards, with their own network management flavors and a little Web-based management tossed in.

Scalability. Simply adding users to a switch or connecting your switch to a network backbone switch is one way to scale your network upward. Rackmountable switches are more easily scalable than standalone desktop switches.

VLAN support. Managed Layer 2 switches such as Accton's $785 CheetahSwitch Workgroup 3514F and all of IBM's 8275 series can support virtual LANs, either as a bundled or optional feature.

Users can be linked by media access control addresses, IP addresses, network protocols or even the port numbers of a LAN switch into a virtual grouping that can share network resources and bandwidth.

VLANs are tied to Layer 2 technology, however, and as Layer 3 switches providing full Gigabit Ethernet wire-speed routing enter the market, they may disappear.

Diagnostic port LEDs. LED indicators at each switch port generally indicate the activity of the link, such as 10-Mbps or 100-Mbps bandwidth utilization or collision/full-duplex. An on/off switch LED light is included with virtually all switches.

Media compatibility. A big advantage to 100Base-T Fast Ethernet is that it runs over the same 10Base-T media that standard Ethernet uses. 100Base-TX'two pairs of data-grade Category 54 unshielded and shielded twisted-pair wiring'and 100Base-FX'two strands of multimode fiber'have emerged as the most popular cabling schemes in most wiring closets, so be sure that your switch supports them with appropriate connectors. The most popular media for Gigabit Ethernet uplinks is 1000Base-SX, which uses multimode fiber, but the more versatile, copper-based 1000Base-CX technology is coming on strong.

J.B. Miles of Pahoa, Hawaii, writes about communications and computers.






























































































































































































































































































































VendorProductManaged/
unmanaged
10/100-Mbps
ports
ExpansionConfigurationKey switching featuresPrice
Accton Technology Corp.
Irvine, Calif.
949-707-2400
www.accton.com
CheetahSwitch
Workgroup 3008A
UnmanagedEightOne shared 10/100
uplink port
DesktopStore-and-forward,
full- and half-duplex, auto-
negotiation, plug-and-play,
self-learning configuration
$199
CheetahSwitch
Workgroup 3016A
Unmanaged16SameDesktopSame$325
CheetahSwitch
Workgroup 3024C
Unmanaged24SameDesktopSame$544
CheetahSwitch
Workgroup 3514F
SNMP, RMON,
Telnet, Web-
based
12Optional 1000Base
(gigabit) uplink
RackmountStore-and-forward,
full- and half-duplex, auto-
negotiation, VLAN support
$785
CheetahSwitch
Workgroup 3526F
Same24SameRackmountSame$979
Allied Telesyn International
Corp.
Sunnyvale, Calif.
408-730-0950
www.alliedtelesyn.com
AT-8118-10AT-View, SNMP,
Telnet, Web-
based
16Two optional
10/100TX or
100FX uplink ports
RackmountCut-through or store-
and-forward, full- and half-
duplex, auto-negotiation,
automatic address learning
$1,369
AT-8126XLSame24SameRackmountSame$939
AT-FS716Unmanaged16N/ARackmountSame$411
ARK Technologies
Orange, Calif.
714-997-4597
www.arkpc.com
CT2208D/CT2208DIUnmanagedEightOne shared MDI-II
uplink port
Desktop or
rackmount
Store-and-forward,
full- and half-duplex,
auto-negotiation
$75
CT2216DUnmanaged16Two shared MDI-II
uplink ports
Desktop or
rackmount
Same$185
Asante Technologies Inc.
San Jose, Calif.
408-435-8388
www.asante.com
FriendlyNet FS4008PUnmanagedEightOne 10/100 uplink
port
Desktop or
rackmount
Store-and-forward,
full- and half-duplex,
auto-negotiation
$149
FriendlyNet FS4016PUnmanaged16One 10/100 uplink
port
SameSame$549
FriendlyNet FS4024PUnmanaged24
One 10/100 uplink
port
SameSame$689
IntraSwitch 6224MSNMP, Telnet,
Web-based
24
Two MDI-II uplink
ports
RackmountSame$999
Cisco Systems Inc.
San Jose, Calif.
408-526-4000
www.cisco.com
Catalyst 2912 XLCiscoWorks,
SNMP, Telnet,
Cisco CGMP
12N/ARackmountStore-and-forward,
full- and half-duplex,
auto-negotiation, VLAN support
$964
Catalyst 2912MF XLSame12Two 10/100 uplink
ports
RackmountSame$1,001
Catalyst 2924 XLSame24N/ARackmountSame$1,315
Catalyst 2924C XL
Same
24
Two 100Base-FX
ports
RackmountSame$1,927
Catalyst 2924M XLSame24Two 10/100 uplink
ports
RackmountSame$1,614
Compex Inc.
Anaheim, Calif.
714-630-7302
www.cpx.com
PS2208 Pocket SwitchUnmanagedEight
One shared 10/100
uplink port
DesktopStore-and-forward,
full- and half-duplex,
auto-negotiation
$131
D-Link Systems Inc.
Irvine, Calif.
949-788-0805
www.dlink.com
DSS-8+UnmanagedEightOne MDI-II uplink
port
DesktopStore-and-forward,
full- and half-duplex,
auto-negotiation, VLAN support
$87
DSS-16+Unmanaged16Two MDI-II uplink
ports
DesktopSame$297
Edimax Computer Co.
Santa Clara, Calif.
408-496-1105
www.edimax.com
ES-3108PUnmanagedEightOne shared 10/100
uplink port
RackmountStore-and-forward,
full- and half-duplex,
auto-negotiation
$149
ES-3116RUnmanaged16SameRackmountSame$395
Farallon Communications
Inc.
San Leandro, Calif.
510-814-5000
www.farallon.com
Fast Starlet
Palm Switch
UnmanagedEightN/ADesktopStore-and-forward,
full- and half-duplex, auto-negotiation
$153
Fast Starlet Switch 16Unmanaged16One 100Base-FX
port
RackmountSame$378
Fast Starlet Switch 24Unmanaged24SameRackmountSame$396
Garrett Communications
Inc.
Fremont, Calif.
510-438-9071
www.garrettcom.com
Magnum 4K8UnmanagedEightOne or two optional
100Base-FX ports
RackmountStore-and-forward,
full- and half-duplex, auto-negotiation
$599
Magnum 4K16Unmanaged16SameRackmountSame$899
Magnum 4K24Unmanaged24SameRackmountSame$1,199
Hewlett-Packard Co.
Palo Alto, Calif.
650-857-1501
www.hp.com
ProCurve Switch 408UnmanagedEightOne MDI/MDI-X portRackmountStore-and-forward,
full- and half-duplex, auto-negotiation
$229
ProCurve
Switch 1600M
SNMP, Telnet,
Web-based
16One MDI/MDI-X portRackmountSame$1,099
ProCurve Switch 2224Unmanaged
24One open
transceiver slot
RackmountSame$529



































































































































































































































































































































VendorProductManaged/
unmanaged
10/100-Mbps
ports
ExpansionConfigurationKey switching featuresPrice
Hawking Technologies Inc.
Irvine, Calif.
949-580-0888
www.hawkingtech.com
Model PN636ESUnmanaged16Two 10/100 uplink
ports
RackmountStore-and-forward,
full- and half-duplex,
auto-negotiation
$321
Model PN2400ESUnmanaged24SameRackmountSame$445
IBM Corp.
Armonk, N.Y.
914-765-1900
www.ibm.com
8275 Series Model 318SNMP, RMON,
Web-based
161000Base-SX
and 100Base-FX
port options
Desktop,
rackmount
Store-and-forward,
full- and half-duplex,
auto-negotiation, VLAN support
$1,425
8275 Series Model 322Optional20SameSameSame$995
8275 Series Model 326Optional24SameSameSame$715
Intel Corp.
Santa Clara, Calif.
408-765-8080
www.intel.com
Intel Express 410T
Standalone Switch
Intel Device
View, SNMP,
RMON, Web-
based
16, 24N/ARackmountStore-and-forward,
full- and half-duplex,
auto-negotiation
$546
Intel Express 510T
Standalone Switch
Same24N/ARackmountSame$1,570
Kingston Technology Co.
Fountain Valley, Calif.
714-435-2600
www.kingston.com
KNS800/WGUnmanagedEightUTP port 5DesktopStore-and-forward,
full- and half-duplex,
auto-negotiation
$152
Lancast Inc.
Nashua, N.H.
603-880-1833
www.lancast.com
CenturySwitch 3508-11
with Fiber Uplink
UnmanagedEightOne 100Base-FX
uplink port
DesktopStore-and-forward,
full- and half-duplex,
auto-negotiation
$359
CenturySwitch 3508-01UnmanagedEightN/ADesktopSame$539
CenturySwitch 3512-01Unmanaged12N/ADesktopSame$899
Linksys International
Irvine, Calif.
949-261-1288
www.linksys.com
DSSX12Unmanaged12One 100Base-FX
uplink port
DesktopStore-and-forward,
full- and half-duplex, auto-negotiation
$358
DSSX16Unmanaged16SameDesktopSame$449
DSSX24Unmanaged24SameDesktopSame$565
Lucent Technologies Inc.
Murray Hill, N.J.
980-582-6500
www.lucent.com
Cajun P120
Workgroup Switch
Cajun P120
Manager with
SNMP, RMON,
Lucent SMON
24Optional 10/100,
100Base-FX or
1000Base-SX/LX
ports
DesktopStore-and-forward,
full- and half-duplex,
auto-negotiation
$1,755
GSA
Marconi Communications
Corp.
Warrendale, Pa.
724-742-4444
www.marconi.com
Fore ES-1000Unmanaged22Two optional
1000Base-SX/LX
ports
RackmountStore-and-forward;
expansion modules
for addition of up to
four 10/100 ports
$2,040
Network Peripherals Inc.
Milpitas, Calif.
408-321-9218
www.npix.com
NuSwitch DS12ASNMP, RMON,
Telnet, Web-
based, console
port
12Optional
100Base-FX
uplink port
RackmountStore-and-forward,
full- and half-duplex,
auto-negotiation
$1,193
NuSwitch DS16Same16One 10/100 uplink
port or optional
100Base-FX port
RackmountSame$1,387
Nortel Networks Corp.
Brampton, Ontario
905-863-0000
www.nortelnetworks.com
BayStack 70-8TUnmanagedEightOne MDI/MDI-X
push-button
option
DesktopStore-and-forward,
full- and half-duplex,
auto-negotiation
$350
BayStack 70-16TUnmanaged16SameDesktopSame$595
BayStack 70-24TUnmanaged24SameRackmountSame$994
OvisLink Technologies
Corp.
City of Industry, Calif.
626-854-1805
www.ovislink.com
Ether-FSH8TXUnmanagedEightN/ADesktopStore-and-forward,
full- and half-duplex,
auto-negotiation
$138
Ether-FSH16TXUnmanaged16N/ADesktopSame$375
Ether-FSH24TXUnmanaged24N/ADesktopSame$595
SMC Networks
Irvine, Calif.
949-707-2400
www.smc.com
EZ Switch II
Model 6308TX
UnmanagedEightOne 10/100 uplink
port
DesktopStore-and-forward,
full- and half-duplex,
auto-negotiation, self-configuring
$140
TigerSwitch 10/100
Model SMC6912M
SMC EliteView,
SNMP, RMON
12Two 100Base-FX
ports
RackmountSame$986
TigerSwitch 10/100
Model SMC6924M
SMC EliteView,
SNMP, RMON
24SameRackmountSame$1,232
3Com Corp.
Santa Clara, Calif.
408-764-4000
www.3com.com
OfficeConnect Dual
Speed Switch 8
UnmanagedEightOne MDI/MDI-X
uplink port
DesktopStore-and-forward,
full- and half-duplex, auto-negotiation
$210
OfficeConnect Dual
Speed Switch 16
Unmanaged16One MDI/MDI-X
uplink port
DesktopSame$390
Trendware International
Inc.
Torrance, Calif.
310-891-1100
www.trendware.com
TE100-S1616Unmanaged16One shared MDI-II
port, optional MDA
100Base-FX port
RackmountStore-and-forward,
full- and half-duplex,
auto-negotiation
$363
TE100-S2424Unmanaged24SameRackmountSame$518
Unicom Electric Inc.
Rowland Heights, Calif.
626-964-7873
www.unicomlink.com
Dyna Switch 16Unmanaged16One fixed 10/100RackmountStore-and-forward,
full- andhalf-duplex,
auto-negotiation,
optional VLAN support
$349
Smart-Switch/24SNMP, RMON24One fixed 10/100RackmountSame$1,575

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