I wanted to put this information out there and really didnt know where to post it, so here it goes.
My setup: Xfinity Gigabit service with XFi advantage. Technicolor XB6 modem in bridge mode connected via CAT6 to Netgear Orbi AC3000 (RBR50) router with 1 RBS50 satellite.
At any given time I have 18-22 devices on my network at home. I have 3 teenagers so enough said. We have always had pretty reliable service testing on wired up to about 650Mbps and 400Mbps on wireless. The gigabit service is new to our area, and when I signed up for it (about a year ago), i chalked the speeds up to just being a new service. About 3 weeks ago, I noticed that my wireless speeds were never better than 250Mbps, so I decided to finally call out a technician. When we first got the gigabit service activated, they brought out the XB6 router and installed a MOCA amplifier from the service line to the house. This is common practice in areas where signals are low at the termination point.
The technician came out, replaced a few connectors, and tested the line with his meter, which I guess has an internal modem. He was able to get a single test of 900Mbps, but then could only get 500Mbps on a wired connection. My wireless dropped to about 150Mbps. He said that he could not find anything wrong, and that he would contact maintenance to see if there was anything wrong on their end of the network.
After 2 days, I finally just had enough. Here is what I have learned about the XB6. It is a new(er) device that is capable of DOCSIS 3.1, which is the protocol required to be able to move 1Gbps over the coax line. In the XB6 management software, we are able to see the signal levels of the channels it is connected to. https://pickmymodem.com/signal-levels-docsis-3-03-1-cable-modem/ . This site shows desired and required levels for power level and signal to noise ratio (SNR) on a DOCSIS 3.1 connection. My downstream signal levels were outside of the -7.0 to +7.0 range, and power levels were at about 29-30db. Not at all bad, but definitely outside of the desired range.
I exhausted all efforts of resetting, rebooting, reconnecting that i could think of. I then turned my attention to the MOCA amplifier. I actually found the recommended connection setup for it. https://futurereadysolutions.com/wp-content/uploads/EVO19UU_Installation_Guide.pdf . Referring to example #1 on the diagram, I noticed that the modem was connected port labeled for eMTA/Voice modem. This port is labeled as a signal level of 4.5db whereas all other ports are labeled for 0db. My theory is that this port is barely amplified, if at all, for a voice modem. The other ports are labeled for cable/tv/data modem.
I switched my modem to the p1 port and rechecked my channel levels. All signal levels are within -4.0 to 4.0 and power levels are all above 40. I am now getting ~950Mbps on wired and ~700Mbps on wireless over the Orbi system. I can understand the confusion because the voice modem port does say "modem" on it.
Hopefully someone can benefit from this research and get the service they are paying for. Comcast just needs to make sure their technicians know this part. Its been a pretty good day with blazing fast and reliable service.
Description from manufacturer:
Standard 5 & 9 Port Active Return Amplifier Coax Splitter
The Entry Series incorporates a completely passive Voice Modem/eMTA port for customers who offer landline voice service. Critical communication signals passing to and from the voice modem are never jeopardized by having to pass through active components (e.g. relays) like those found in typical bypass amplifers. The Entry Series (EV01-9-x/x) is a 9-output device with one
all-passive port for Voice Modems (or eMTAs/HSD) and eightports with gain for video or high speed data services. The all-passive Voice Modem Port (-3.5 dB) maintains signal integrity to and from the voice modem/eMTA in the event of a power outage.
You state that none of the ports are amplified, but it clearly states that only the 8 ports not for the voice modem are amplified, or have "gain", which is amplification, hence the name amplifier. When i remove the amplifier, all signal levels fall to less than acceptable range, and even my TV is choppy. Considering the voice port being completely passive, i would designate it as being un-amplified, since it is just a passthrough, bypassing all amplification circuits. This would allow it to still work if the the amplification circuits turn off. In this case, connecting it to the voice port is an incorrect installation as the XB6 needs the correct signal ranges to operate up to the expected 1Gbps. The problem here is the misinformation and techs just accepting signal ranges outside of what is required for DOCSIS 3.1.