MoCA Cable Plant Back-feeding

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Brak710

[H]ard|Gawd
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I think this might be a slightly shady topic since it could be used nefariously, but has anyone had issues with MoCA adapters back-feeding the local cable plant?

I know they sell MoCA filters, but majority of the MoCA adapters I see don't have any sort of protection included against this nor even make a mention that it would be nessecary.

How far would these MoCA signals travel? Would it interfere with cable company equipment on the node?
 
Brak710 said:
I think this might be a slightly shady topic since it could be used nefariously, but has anyone had issues with MoCA adapters back-feeding the local cable plant?

I know they sell MoCA filters, but majority of the MoCA adapters I see don't have any sort of protection included against this nor even make a mention that it would be nessecary.

How far would these MoCA signals travel? Would it interfere with cable company equipment on the node?
Click to expand...

Moca can usually only go as far as the first amplifier or line extender in a cable plant. That is because these amps only handle the 5 Mhz - ~1 Ghz range where Moca does its magic in the 2 Ghz (if I remember correctly). So, unfiltered Moca adapters are only going to "back-feed" into other subcribers on the same tap (small pedestal outside where multiple houses or drops are services from) e.g. your neighbors. If one of these neighbors have a small signal booster amp in their house then that will probably thwart all incoming Moca as well. This is because of the same 5 - 1000 Mhz frequency range line amps are designed for.

Moca adapters that I have seen also offer some kind of encryption that pair devices together so your neighbor can't join your lan... unless you want him to ;)
 
Ehren8879 said:
Moca can usually only go as far as the first amplifier or line extender in a cable plant. That is because these amps only handle the 5 Mhz - ~1 Ghz range where Moca does its magic in the 2 Ghz (if I remember correctly). So, unfiltered Moca adapters are only going to "back-feed" into other subcribers on the same tap (small pedestal outside where multiple houses or drops are services from) e.g. your neighbors. If one of these neighbors have a small signal booster amp in their house then that will probably thwart all incoming Moca as well. This is because of the same 5 - 1000 Mhz frequency range line amps are designed for.

Moca adapters that I have seen also offer some kind of encryption that pair devices together so your neighbor can't join your lan... unless you want him to ;)
Click to expand...

Depends on what spec of MoCA is being used. 1.1 has 2 ranges, 500-850mhz and 850-1500mhz. The first is Designed to work with DirectTV and the other is for using with CATV systems. 2.0 IIRC only has one range and that is 500-1650.
 
The other thing to consider is that in order for data to pass bidirectionally, a special amplifier has to be used. Now granted, with the ubiquity of cable modems and STB's these days, the majority of amplifiers should have a return path.

Alternatively, you could get a directional coupler, which has low insertion loss but high return loss, though finding one made for the near 1GHz bandwidth of CATV systems might be somewhat difficult.
 
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