Compex PS2216 Switch

Review by Harry Lam on 02.12.03
Switch provided by Compex, MSRP: $89.95

Features of the Compex PS2216 Switch:

Dip switches on the side

The Compex PS2216 Switch isn't just a regular switch but also boasts some high-end features that are only available on more expensive switches (usually rack-mounted switches for corporate networks).  These features are stripped down versions of their high-end counterparts, but more than adequate for almost all homes, and even some offices.  I'm going to dissect these features in depth, and explain what exactly they do behind the technical alphabet soup.

• 16 10/100Mbps Fast Ethernet Ports Supporting N-Way Auto-Negotiation
  This is relatively self explanatory, 16 10/100 Ethernet ports on the PS2216.  N-Way Auto-Negotiation basically allows the switch to detect the speed and duplex on each port and automatically configuring it to the most optimal speed.  With N-Way Auto-Negotiation, the switch is able to detect the cable type and speeds on the fly, so both crossover and regular cables will work with this switch (and whatever type of cable, CAT 3-5).
• Full Bandwidth Non-Blocking Switch Architecture
  Basically, this allows every port on the switch to perform at their maximum speed of 200Mbps a second, with a 3.2Gbps backplane (in their data sheet, they compare it to the 100MBps backplane of a hub).
• Dynamic Address Learning & Filtering
  This feature explains how a switch builds a MAC address table and directs packets directly from their source to destination, cutting down on both excess network traffic as well as collisions.
• Complaint with Industry Standards
  The PS2216 adheres to the IEEE 802.3 and IEEE 802.3u standards (10Base-T and 100Base-TX respectively), so it will fit in with all existing Ethernet equipment (basically a no brainier).
• Small Compact Desktop Casing
  This switch is very small, taking a space of about 151 x 92 x 32mm.
• Port Trunking
  This is one of the high end features on the PS2216.  On most regular switches, if you want to daisy chain multiple switches together, you have to use an uplink port, which basically is just a port configured to communicate with another switch.  In the scenario, the communication between the switches is only limited to 200Mbps (as it's full duplex on a 100Mbps port).  On expensive switches, this is usually implemented via a gigabit port (usually fiber, but gigabit Ethernet is also used.  The PS2216 can use the regular uplink method (200Mbps) or it can use port trunking with four 100Mbps ports (giving a max bandwidth of 800Mbps between the switches).  Although in this case, it ties up four ports on each switch, this is a very low cost performance solution for interconnecting two switches.
  The PS2216 allows for two groups of four ports for Port Trunking if you want to connect a series of switches.
• Virtual VLAN
  VLAN functionality is another one of those high end features primarily found on higher-cost business switch.  VLANs restrict the size of a broadcast domain (basically it segments groups of computers into virtual LANs (or virtual workgroups).  Broadcasts are only contained with each VLAN, cutting down on the excess traffic transmitted to each node (which also is something that slows down networks when they're too large).  Essentially, it's like if each VLAN were all connected to different routers and couldn't directly interface with each other.
  The VLAN implementation on the PS2216 is port based VLAN.  Basically each port is on it's own VLAN, and Port 1 is the common port (the port which all broadcasts get sent to, no matter which VLAN).  In a typical setup, another switch or hub would be connected to each port to form their own VLAN (and in a way, the switch works as a router in certain functions).