Hubs

 

Introduction.  Since we have already said quite a bit about hubs elsewhere, this page will mostly be a product review.  A hub is a passive device that acts as a central connecting point by taking in lines from individual devices, mainly PCs, servers and printers, to form individual LAN segments.  Devices that are connected to the same hub are in the same LAN segment and they share the hub's bandwidth.  Essentially, a hub repeats incoming signals to all attached devices.

Now we need to give brief descriptions of some terminology related to hubs that will be useful in answering the following four questions which characterize the main hub properties you need to consider.

  • Can the hub be stacked or can it be used only as stand-alone?
    • Hubs are stackable if a special cable can be run between IN and OUT stack ports in each hub to create a single logical hub.  Usually a stack can have up to four hubs.
  • Is the hub model's chassis modular or fixed configuration?
    • Modular implies that additional modules/printed circuit boards can be inserted into the chassis in order to expand its configuration.  Modules are usually added to increase the number of ports.
  • Can the hub be managed?
  • What LAN protocol(s) can the hub support?

 

The following table lists the major CISCO products.  Subsequent tables list product lines from other sources.

 

Cisco Hubs
Product Series

Description
Cisco MicroHub 1538 Eight port 10/100 autosensing device that comes in managed and automanaging units where one managed unit can be used to indirectly manage three other manageable units in a four stack hub.
Cisco FastHub Series Four models ranging from 12 to 24 ports with 10/100 autosensing ports per chassis..
10BaseT Hub Developed with Hewlett-Packard, this is a Fast Ethernet 10/100 fixed configuration managed hub optimized for use with Cisco Catalyst 1900 and 2820 Series switches.  It is not stackable.
Cisco VPN 3000 Series Concentrator Carrier class Fast Ethernet 10/100 VPN concentrators.  Includes VPN client software including encryption and authentication techniques.  Supports up to 10,000  encryption tunnels.
Cisco VPN 5000 Series Concentrator Carrier class Fast Ethernet 10/100 VPN concentrators.  Includes VPN client software including encryption and authentication techniques.  Supports between 1,500 and 40,000 encryption tunnels.
Specialty Hubs Concentrators used in specialized environments such as FDDI.

 

 

This information will be updated intermittently.   In addition, I will post some offerings from CISCO competitors while trying to focus on those with largest market share.  Any assistance in this will be greatly appreciated.