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Netgear FS108 Fast Ethernet Switch

During the replacement of the networking onboard nb Tanya Louise with gigabit, the main 8-port distribution switch was also changed. Here’s a quick teardown of the old one.

Netgear FS108
Netgear FS108

This has been quite a reliable switch for the internal networking on board, but the time has come to switch over to something a little faster. This switch will be getting repurposed for the slower devices on my network, such as the radiation monitor & the raspberry Pi systems.

Cover Removed
Cover Removed

Here’s the top removed from the switch. It’s a very simple construction, with a small power supply section & the main switch IC in the centre.

Main Switch IC
Main Switch IC

All the magic happens in this main IC, a Realtek RTL8309SB Fast Ethernet switch. This is a feature-packed IC, with support for VLAN tagging, but being in a small unmanaged switch the extra features aren’t used.

Power Supply
Power Supply

Main power supply is provided by a jelly bean MC34063 DC-DC converter, and an adjustable LM1117 linear regulator. Nothing much special here.

Ethernet Magnetics
Ethernet Magnetics

The only other parts are the magnetics for the ethernet interfaces, behind the ports themselves.

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Netgear GS308 Gigabit Switch

Here’s a new addition to the network, mainly to replace the ancient Cisco Catalyst 3500 XL 100MB switch I’ve been using for many years, until I can find a decently priced second hand commercial gigabit switch.

Operational
Operational

Here’s the switch with some network connections on test. So far it’s very stable & draws minimum power. I’ve not yet attempted to run my core links (NAS) through yet, as I’ve not yet seen a consumer grade switch that can stand up to constant full load without crashing.

Internals
Internals

Here’s the switch with it’s lid popped. The magnetics can be seen at the back, next to the RJ-45 ports, the large IC in the centre is the main switching IC, with a heatsink bonded to the top. Very minimal design, with only a couple of switching regulators for power supply & not much else.

Power & EEPROM
Power & EEPROM

Here’s a closeup of some of the support components. There’s a 25MHz crystal providing a clock signal for the switch IC, just to the right of that is an EEPROM. I imagine this is storing the switch configuration & MAC address. Further right is one of the switching DC-DC converter ICs for power.

As a quick test, here’s 500GB of data being shifted through the switch, at quite an impressive rate. I’m clearly maxing out the bandwidth of the link here. Soon I will upgrade to a 10G Ethernet link between the NAS & main PC to get some more performance.

Test
Test