Are you sure you really need a gigabit connection from your house to your workshop? The gigabit connection does nothing for your internet connection and is only useful for very high speed data transfers on computers or NAS within your LAN. Are you using equipment with true gigabit ports and performance on them? Do you really need that kind of LAN speed?

If not, just break out an unused 10/100 pair from the CAT6 before the terminating connector at each end to use for your POTS. By definition, any VOIP adapter whether LAN or WAN is no longer POTS and will require an active network.

While it's possible to design a low pass/high pass filter to separate the two, the same as is used for DSL delivered over phone lines to the house, it will inherently drop your speed back down to a 10/100 Mbps LAN.

There are places where I need (want) the high speed link, for transferring video files that I'm editing between machines and NAS, but I don't need that in the shop. I was told (incorrectly?) that slow links anywhere would drop the network speed everywhere. I was using the excuse of moving into a new house for upgrading all of my switches and wiring to gigabit capability. The central connection point is planned to be a Netgear ProSafe Plus Gigabit switch. If running this line at 10/100 speed won't mess up the rest I'll happily do that. I guess I need to read more.

I looked at the Netgear website and that line of switches offer 10/100/1000 auto-sensing on each port - as well as user configuration capabilities.

If you have a 10/100 device on one port and Gigabit (1000) devices on other ports, the switch should just set each port speed accordingly.

Occasionally, you may have to manually configure a port if the the auto-sensing can't determine a device's duplex mode and drops to 1/2 duplex on 10/100 devices.

Nice feature with that Netgear switch is the configuration software will also allow you to prioritize video data packets over selected ports which should be perfect for your video editing suite.

Thanks, that seems to be right and nicely solves my problem. Appreciate the prompt to look in that direction.

Eithernet cable uses 1&2 and 7&8 for DC to power units so 3&4 and 5&6 are used for internet. POI or Power Over Internet devices inject the DC power needed to power the units. I would also pull the wire out and re-pull in another eithernet cable or if you can find an old 4 wire telephone line and they are about 3/16 inch thick pull it back in. There is a product called yellow 77 and it is a wire pull slippery substance for making wire pulling easier. I also would like to extend my Canadian phone to USA via internet while I am there so also looking at ways to extend many miles. Earl

Way to late to this thread but for future reference...the company Markertek sells devices for carrying just about any signal over just about any [incorrect for signal] wire. I don't remember seeing a way to piggyback POTS onto ethernet (other than just wiring the ethernet for phone) but if anybody would know how to do it, they would.
For example, they sell a gizmo to carry HDMI over ethernet, which is pretty remarkable if it works.

I found this: http://www.instructables.com/id/Hack-your-House-Run-both-ethernet-and-phone-over-/