Coax WAN - Ethernet WAN...why?

[AlmostTechnical]

Why is it necessary that both a coax wan and ethernet wan connection are required? I realize VZ states the coax wan connection is needed for guide and vod services, but why? Can't they find a solution where both internet and tv services use just the ethernet connection?

[Cang_Household]

The internet is delivered from ethernet WAN in most Verizon setup. Coax on the ONT is for the Linear TV Signal, which is an analog signal.

If the TV Signal is digitalized on the ethernet, doesn't that occupy your 1 Gigabit bandwidth? The ONT converts light signal to ethernet, Linear TV Signal, and Plain Old Telephone lines. One type of connection is geared specifically for one purpose.

[smith6612]

Coax WAN isn't needed for the data to work on the Set Top Boxes. What matters is that the FiOS Set Top Boxes can talk to the FiOS router using MoCA LAN (Coax) and get their Linear TV signal from the ONT. At the moment, I don't believe Verizon has enabled the Set Top Boxes to use Ethernet for their data connection (which would be really convenient in some cases!) directly.

Ethernet WAN is used on new installs, or when your connection speed exceeds 100Mbps, since the MoCA hardware in the ONTs and many of the older FiOS routers, is not capable of reaching >100Mbps subscribed speeds over Coax. 

[gs0b · Accepted solution]

Lots of misinformation in the previous posts.

FiOS has three communications channels on the fiber.  They are different wavelengths of light.  If you think of them like different radio channels, you've got the right idea.  The three channels are used as follows:

• Downstream data.  Just like it's named, it carries data services.  Primarily internet.
• Upstream data.  Another clear name - this is the data sent to the network.
• QAM Video.  This carries all of the TV channels.  Also known as linear TV.  It is similar to signal on a cable system, just converted to light.  It's an RF signal covering about 1GHz of spectrum; subdivided into channels.  The channels themselves are digitally modulated using QAM.  I would not call it "analog," as it carries fully digital information.  Unlike cable, there is no upstream path.

The ONT's job is interface to the fiber and present services on it's interfaces.  An Optical Line Terminal (OLT) is at the other end and connects to the various service sources.  Here's how the ONT's ports map to the above wavelengths:

• WAN (Ethernet or MoCA): Connected to the upstream and downstream data wavelengths.
• Phone: Connected via a VoIP terminal inside the ONT.  The terminal is connected to the upstream and downstream data wavelengths.  It uses a different data stream than user internet data.
• TV channels (coax): A straight optical to electrical conversion from the QAM wavelength.  If you know what a trans-impedance amplifier is, this is how it's done.

Set-top-boxes (except for FiOS ONE minis), get their TV channels from the coax output of the ONT.  However, unlike cable systems, that there is no upstream path for TV on the QAM wavelength.  This means that set-top-boxes use the data path for all communication other than linear TV.  Command, control, guide data, streaming video and more are use this communications path.  The set-top-box must have a LAN connection to the router for this link.  For the older boxes and the new FiOS ONE main box, this is done over MoCA LAN (not to be confused with MoCA WAN). 

Meanwhile, the router needs to connect to the ONT's WAN port for internet service.  This can be over Ethernet or coax.  MoCA WAN connection is separate the the TV channels and MoCA LAN.  Regarldess of if Ethernet or MoCA WAN is used, the router needs to connect to coax to create a MoCA LAN for the set-top-boxes.  If you look closely inside the router, you can see it has two MoCA ports (WAN and LAN).  There is an internal splitter, but that's harder to see.

When Ethernet WAN is used, the router and set-top-boxes still need coax connections for the MoCA LAN.   That's why you see both Ethernet and Coax on Verizon routers in TV subscribing households.

The new FiOS ONE system adds another wrinkle.  The main box has six tuners in it.  These tuners access the QAM channels.  The mini boxes have no tuners!  Instead, the main box streams the user's selected channel over the LAN to the box.  This can happen over MoCA, Ethernet or WiFi.  The mini's are pure IP devices, but the streaming is entirely local.

To completely get rid of coax, FiOS would have to switch to IP video streamed from the equipment behind the OLT, over the data path to devices like the FiOS ONE Minis. This may happen some day, but requires significant re-engineering of the network to support a much larger streaming load.

If you want to learn more, google...