# MOCA, minis and PHY



## mtnbkr (Sep 3, 2016)

New TIVO user here and I am trying to understand why the PHY rates to my two minis are so different. Power levels are about the same, which to me suggest the cable runs are about equal, so why the drop in data rate on one of them?

Thx.


----------



## krkaufman (Nov 25, 2003)

mtnbkr said:


> New TIVO user here and I am trying to understand why the PHY rates to my two minis are so different. Power levels are about the same, which to me suggest the cable runs are about equal, so why the drop in data rate on one of them?


Your power levels are showing as the same because they're both at the maximum allowed, +3.0 dBm (or a doubling of the norm power level), which is a good indicator of impediments to a solid MoCA connection.

I was just writing-up something on the subject for posting to the TiVo troubleshooting forum, and so will CC it here...

_The MoCA "power estimate" communicates how hard a MoCA adapter is working (i.e. how it is modifying its MoCA signal strength) to make & maintain its MoCA connectivity. The power range is -30.0 dBm to +3.0 dBm, with a -30.0 dBm power reduction factor indicating the best possible quality for a coax/MoCA connection, while a +3.0 dBm boost (doubling) of the norm MoCA signal strength is the max that the MoCA adapters can push, and is an indicator of severe impediments to MoCA connectivity -- if you can establish a connection at all.

In the real world, the best power level I've seen, with a Mini connected via 1-ft coax directly to a MoCA adapter is -27.0 dBm. Even my current MoCA setup (5 Minis connected through a couple cascaded 4-way 2.0 GHz digital splitters to an Actiontec ECB3500T) initially reports -17.0 dBm and eventually stabilizes at -27.0 dBm.

In my brief experience, I'd definitely be looking to improve my setup if my power levels are any worse than -10.0 dBm (i.e.in the -10.0 dBm to +3.0 dBm range), and probably considering it for any power levels higher than -15.0 dBm._​With that said, I'd recommend a thorough review of your coax plant to identify where it diverges from MoCA compliance. If you want some help with the effort, I recommend posting a diagram of your setup, including available coax and Ethernet runs in each room, how the runs interconnect (via what specific coax or networking components), how the coax lines route from their point-of-entry (cable provider or antenna), and what equipment is located in each room (ideally including model #s). (see attached for a couple example diagrams, not necessarily applicable to your setup, for inspiration; accuracy and completeness are valued over attractiveness)

edit: p.s. In your case, since you've provided some useful MoCA stats already, it might be useful to also indicate each MoCA device on the diagram by the last 3 segments of their MAC addresses (e.g. "8d:16:96", "8d:16:ce").
.


----------



## krkaufman (Nov 25, 2003)

mtnbkr said:


> New TIVO user here and I am trying to understand why the PHY rates to my two minis are so different. Power levels are about the same, which to me suggest the cable runs are about equal, so why the drop in data rate on one of them?


p.s. More to your specific example, if your coax lines weren't quite as hostile to MoCA, you might see both Minis with similar PHY rates, but with one having to apply a bit more power to get there. However, having hit the limit for how much the MoCA signal can be boosted, the PHY rate will begin to suffer.


----------



## mtnbkr (Sep 3, 2016)

This is my layout.

There is a POE on my line where it connects to TWC in the data closet down the hallway from my apartment, and there is a POE on the input to the tuning adapter.

All runs are less than 50 feet.


----------



## fcfc2 (Feb 19, 2015)

mtnbkr said:


> This is my layout.
> 
> There is a POE on my line where it connects to TWC in the data closet down the hallway from my apartment, and there is a POE on the input to the tuning adapter.
> 
> All runs are less than 50 feet.


I assume you are using the Tivo DVR to create a MoCA network. If this is the case, the best place for a MoCA filter would be on the input of that 4 way splitter. 
You also don't really say what issue you are having with the MoCA other than the power levels. But, what ever it is, other than adding a filter on the 4 way would be to swap out the 4 way and the 2 way for MoCA rated splitters from Holland or Verizon and take a good look at your coax connectors, make sure you have the compression type on all fittings. Look carefully to insure none of the fine wire braid got jammed down inside where the center conductor is.


----------



## mtnbkr (Sep 3, 2016)

I found the problem it was one bad F connector on my splitter that the builder installed and it was shorting out one of my drops.


----------

