Re: PoE, Comcast Modems, and Service Outages

On Wed, Mar 30, 2022 at 05:52:06PM +, Livingood, Jason wrote: > > Their crappy equipment needing rebooting every few weeks, not ridiculous. > > Their purchasing gear from incompetent vendors who cannot be standards > compliant for PoE PD negotiation, tragically plausible. > > Many

Re: PoE, Comcast Modems, and Service Outages

On 3/30/22 10:52, Livingood, Jason via NANOG wrote: Could well be from noise ingress - lots of work goes into finding & fixing ingress issues. Hard to say unless we look in detail at the connection in question and the neighborhood node. Packet loss absolutely could be noise ingress. That's

Re: PoE, Comcast Modems, and Service Outages

Thanks Jason—they are all are business connections. I know they can be restarted through the business portal, but honestly the business portal is terrible for large clients. Not all our connections are listed under the same account due to something with Comcast and the way "regions" and various

Re: PoE, Comcast Modems, and Service Outages

On 3/30/22 09:53, Grant Taylor via NANOG wrote: On 3/29/22 2:19 PM, Aaron de Bruyn via NANOG wrote: When you hear hoof beats, look for horses, not zebras. As someone with a family member that is a zebra from a health perspective, I follow up with: Yes, /look/ for horses when you hear hoof

Re: PoE, Comcast Modems, and Service Outages

> I asked him to remotely reboot the modem because there was high packet loss. FWIW, as a customer (assuming residential), you can login to the website and check for area outages/impairments at https://www.xfinity.com/support/status-map. You can also use the Xfinity app to remotely reboot

Re: PoE, Comcast Modems, and Service Outages

> Their crappy equipment needing rebooting every few weeks, not ridiculous. > Their purchasing gear from incompetent vendors who cannot be standards compliant for PoE PD negotiation, tragically plausible. Many customers buy their own cable modem. You can lease an Xfinity device as well and

Re: PoE, Comcast Modems, and Service Outages

On 2022-03-30 12:53 p.m., Grant Taylor via NANOG wrote: We've run into too many people who hear hoof beats, assume horses, and proceed as if zebras are absolutely not a possibility. I'll never forget my first major escalation as a young engineer, on a phone call with multiple angry

Re: PoE, Comcast Modems, and Service Outages

On 3/29/22 3:46 PM, Joe Greco wrote: So if you want the $100 test to eliminate PoE electrical effects, get a pair of media converters and run fiber between them. Put the CPE on the far end. Optimize as appropriate if you have SFP-capable switches. I second this. I'd also be willing to get

Re: PoE, Comcast Modems, and Service Outages

On 3/29/22 2:19 PM, Aaron de Bruyn via NANOG wrote: When you hear hoof beats, look for horses, not zebras. As someone with a family member that is a zebra from a health perspective, I follow up with: Yes, /look/ for horses when you hear hoof beats, but -- and this is the important thing --

Re: PoE, Comcast Modems, and Service Outages

> he said I needed to disable PoE because it messes with the Comcast > modems and he can see "buildups" in his graphs that show power is > "leaking" to the Comcast modem every 24 hours. revealing the critical failure with comcast support; they do not share what they are smoking randy ---

Re: PoE, Comcast Modems, and Service Outages

- On Mar 29, 2022, at 2:46 PM, Joe Greco jgr...@ns.sol.net wrote: Hi, > So if you want the $100 test to eliminate PoE electrical effects, get > a pair of media converters and run fiber between them. Put the CPE on > the far end. Optimize as appropriate if you have SFP-capable switches.

Re: PoE, Comcast Modems, and Service Outages

Generally anything inside the customer premise (including wiring) is the customer’s responsibility. If your coax runs across a fluorescent light fixture, that’s on you. If your coax is RG59, it’s on you to replace with RG6 quad shield. Maybe the cable operator will work with you, maybe not.

Re: PoE, Comcast Modems, and Service Outages

Thanks Blake, As I understand it all that stuff is on the "cable provider" side of the CPE and (within reason) it's up to the provider to deal with the signals arriving on the cable side of the modem. i.e. if it was a blower or something in our suite that was causing RF interference, the provider

Re: PoE, Comcast Modems, and Service Outages

On 3/29/2022 3:24 PM, Joe Greco wrote: He's got graphs showing it every 24 hours? Liar, liar, pants on fire, lazy SOB is looking for an excuse to clear you off the line. Where the heck does this "24 hour" cycle even come from? What SNMP OID is there for "ghostly PoE build-up"? What crontab

Re: PoE, Comcast Modems, and Service Outages

On 3/29/22 2:24 PM, Aaron C. de Bruyn wrote: On Tue, Mar 29, 2022 at 12:20 PM Brie > wrote: Unifi/EdgeSwitch? Yeah.  Unfortunately.  USW-24-250. Oh, I have quite a few of them in service. They work great in my experience as long as you don't shove them in hot

Re: PoE, Comcast Modems, and Service Outages

> On Mar 29, 2022, at 5:46 PM, Joe Greco wrote: > > So if you want the $100 test to eliminate PoE electrical effects, get > a pair of media converters and run fiber between them. Put the CPE on > the far end. Optimize as appropriate if you have SFP-capable switches. > > ... JG > — Bingo

Re: PoE, Comcast Modems, and Service Outages

On Tue, Mar 29, 2022 at 11:21:28AM -0700, Aaron de Bruyn via NANOG wrote: When I said "yes", he said I needed to disable PoE because it messes with the Comcast modems and he can see "buildups" in his graphs that show power is "leaking" to the Comcast modem every 24 hours. This guy must have

Re: PoE, Comcast Modems, and Service Outages

On 2022-03-29 5:46 p.m., Joe Greco wrote: On Tue, Mar 29, 2022 at 03:42:54PM -0400, Josh Luthman wrote: There's a certain manufacturer of TDD radio where the CPU clock is at the same frequency as what Verizon's enodeB will transmit. Even at miles away, it can and will cause PIM issues. Again,

Re: PoE, Comcast Modems, and Service Outages

On Tue, Mar 29, 2022 at 1:12 PM Joe Greco wrote: > So if you want the $100 test to eliminate PoE electrical effects, get > a pair of media converters and run fiber between them. Put the CPE on > the far end. Optimize as appropriate if you have SFP-capable switches. Sure--that would shoot

Re: PoE, Comcast Modems, and Service Outages

On 3/29/22 11:21, Aaron de Bruyn via NANOG wrote: I just got off the phone with a Comcast tech, and wanted to double-check my sanity. Somehow in the last 6 months I've managed to reach the exact same rep twice when dealing with an outage or a degraded service event. I asked him to remotely

Re: PoE, Comcast Modems, and Service Outages

On Tue, Mar 29, 2022 at 12:20 PM Brie wrote: > Unifi/EdgeSwitch? > Yeah. Unfortunately. USW-24-250. > Yeah, you know when 24v passive POE is turned on because it kills the > port on the other end that aren't designed to handle it. Your router > would likely have a dead eth port on it. >

Re: PoE, Comcast Modems, and Service Outages

Just to be clear Josh, I'm not insulting him. I find the situation extremely difficult to believe based on my (possibly incorrect) understanding of how PoE works and very (very!) basic knowledge of things like RF interference—especially when it comes to Cable networks. I mean, the call literally

Re: PoE, Comcast Modems, and Service Outages

On Tue, Mar 29, 2022 at 03:42:54PM -0400, Josh Luthman wrote: > There's a certain manufacturer of TDD radio where the CPU clock is at the > same frequency as what Verizon's enodeB will transmit. Even at miles away, > it can and will cause PIM issues. Again, don't rule it out. I'm not ruling

Re: PoE, Comcast Modems, and Service Outages

There's a certain manufacturer of TDD radio where the CPU clock is at the same frequency as what Verizon's enodeB will transmit. Even at miles away, it can and will cause PIM issues. Again, don't rule it out. Maybe he's just looking for a simple answer that 99% of callers will accept and it

Re: PoE, Comcast Modems, and Service Outages

On Tue, Mar 29, 2022 at 03:07:47PM -0400, Josh Luthman wrote: > We've routinely seen where lines not even connected to the same circuit in > any way (ie an OTA antenna coax line and cat5 POE) cause issues with one > another. As much as we would all love to have a perfect line in the sand, > there

Re: PoE, Comcast Modems, and Service Outages

On 3/29/22 12:21 PM, Aaron de Bruyn via NANOG wrote: Both times I've talked with him, he noted the high packet loss, started to reboot the modem, and then asked me point-blank if we had any PoE switches on our network. This sounds like a guy who has created his own script for 'improving'

Re: PoE, Comcast Modems, and Service Outages

We've routinely seen where lines not even connected to the same circuit in any way (ie an OTA antenna coax line and cat5 POE) cause issues with one another. As much as we would all love to have a perfect line in the sand, there isn't. Don't rule anything out until the issue is resolved. As

Re: PoE, Comcast Modems, and Service Outages

On Tue, Mar 29, 2022 at 11:21:28AM -0700, Aaron de Bruyn via NANOG wrote: > I just got off the phone with a Comcast tech, and wanted to double-check my > sanity. > > Somehow in the last 6 months I've managed to reach the exact same rep twice > when dealing with an outage or a degraded service

PoE, Comcast Modems, and Service Outages

I just got off the phone with a Comcast tech, and wanted to double-check my sanity. Somehow in the last 6 months I've managed to reach the exact same rep twice when dealing with an outage or a degraded service event. I asked him to remotely reboot the modem because there was high packet loss.