This is more of a general connectivity question. I have the Arris TG1682G modem/router (in bridge mode). I've had service under a year and generally been happy with it. Everything seems to working fine - knock on wood. I've noticed my upload has been a bit slower than usual, so decided to look at the modem status. The XFINITY Network page shows 24 channels are locked, but none of the upstream channels are locked, and only the first channel has any info at all but all showing zeros, Modulation at "QPSK" and channel type at "(Unknown)"; all other channels are blank.
I've powered cycled the modem a few times but that hasn't changed anything. I don't recall if I've ever seen the upstream channel locked. I would've thought at least one channel on the upstream should be locked for connectivity. I don't loose connection and the modem doesn't restart automatically as I've read this could happen when connections are bad. Should I be concerned going forward? I'm curious if others are showing the same info.
Solved! Go to Solution.
You should have at least 3 upstream channels, and perhaps 4 or 5.
Please post your gateway's signal information, especially downstream power levels and SNR, upstream power levels, and error log.
Here is a screenshot of the channel info:
The downstream power level ranges between -5.8 and -11.5 dBmV, and SNR between 34.93 and 37.36 dB for all the 24 channels (out of 32). As you can see, the upstream side has no info or completely blank for all the 8 channels. What's weird is everything seems to be working and back to normal this evening (with the upload). What do you make of this? I'm hesistant to bring support into this and risk messing things up.
The image you posted isn't visible. It looks like this:
It's probably because the image requires moderator approval. That might take some time, from a few hours to a day or so. Alternatively, you could upload the image to a file sharing site and post a link to it here, or post text instead of an image.
Hmmm...I was afraid of that. Here are images, hopefully this works https://imgur.com/jHk9DS1
Only 5 of the downstream channels would fit on screen, but channels 6-24 have similar data. Let me know me if you need those as well. From what I've read online, the power levels and SNR are within acceptable ranges. It's just the upstream side that has me scratching my head. I don't know if having the modem in bridge mode has any effect (wouldn't think so) but thought I mentioned again. I also included the event log but they don't show much, nothing shows up on the system log.
@98011 wrote: ... Here are images, hopefully this works https://imgur.com/jHk9DS1 ... I also included the event log ...
I don't know what to make of that. I've never seen a modem or gateway that was operating with zero upstream channels. Downstream power levels are low, especially Index #1, but I don't see how that would kill the upstream channels. And I agree that having the gateway in bridge mode shouldn't be a factor.
I don't see an event log in the linked image.
You might try a factory reset to see if that makes a difference. See RESTORE FACTORY SETTINGS and the Note that follows on https://www.xfinity.com/support/articles/troubleshooting-your-cable-modem. If you do that you'll have to put the device back in bridge mode afterward.
If that doesn't help, I'd swap out the gateway to see how a replacement device behaves.
Sorry about not including the log. I thought I added both images, anyway here is the event log:
This was yesterday's data as there was nothing on the log from today. I will have to find some time to do a factory reset when the fam isn't actively online and see if this resolves it.
Thanks for confirming about the upstream signal. It is an oddity and something for me to keep an eye on going forward. I've never had good cable signal coming into the house, at least when I had TV. To make a long story short, this was the main reason why I don't have cable TV any longer. Comcast was supposed to replace the buried line coming to my house, but they never did many moons ago. At least internet is working fine, hence my reluctance to "mess things up".
Thanks again Bruce and have a great day!
Well, thought I would provide an update. I decided to factory reset the modem and here are the numbers, both in non-bridge and bridge mode, respectively. https://imgur.com/a/ik8RZOU
Lo and behold, the upstream channel shows index #1 as locked now; however, the power level is 57 dBmV. This seems to0 high according to some online comments that I've read. Ideally, it should be in the low to mid 40's(?), anything above 55 could be cause for disconnects.
The line coming into the house already goes directly to modem, no splitters. Is there anything I can do to lower the power level to get more stable upload? I believe the coax line is RG6.
@98011 wrote: ... the power level is 57 dBmV. This seems to0 high ...
It is too high, and it should be locking at least 3 channels. The gateway is probably maxed out. About all you can do is check the condition of the coax, F connectors, and splitters as described about halfway down the page at Connection Troubleshooting Tips.
If you can't find the problem, call in at the phone number on your bill or 1-800-Comcast, or use one of the options on https://www.xfinity.com/support/contact-us/, and insist they send a tech out to identify the cause and correct it.
If the tech finds bad coax, splitters, amplifiers, or connections in your home (even if Comcast originally supplied them) you'll probably have to pay for the visit unless you have their Service Protection Plan (https://www.xfinity.com/support/articles/service-protection-plan, closed to customers that don't already have it). If the trouble is due to a faulty Comcast rental device, or anything outside your home, you shouldn't be charged.