ISP experiences - Comcast/Xfinity for power users?

I live alone and don't push my connection too much, but I do run a few services with OpenWrt so I'm wondering if I'll run into any issues if I switch my ISP.

Right now, I use Wireguard (just to access my home network, not to route internet traffic), SQM, and DDNS on a Uverse line. The AT&T modem doesn't have a true bridge mode but overall, OpenWrt works great with my Linksys WRT32X. I would like to bridge the Comcast modem to my Linksys WRT32X if that's possible?

I'm considering switching to Xfinity for TV+internet and I'm wondering if I'll be able to get roughly the same experience as I have now. Anyone run into something unexpected when they switched to Comcast? Do you use Comcast equipment or your own (and is there a true bridge mode)?

If it matters, I'm in the SF Bay Area. Thanks in advance.

I too am in the SF bay. I found the 1gbit/40 Mbit service comcast offers to be pretty decent (they have the pie aqm), but A) you need a powerful router to keep up at a gbit, and B) putting cake on the uplink helps quite a bit, still.

Yes you can bridge with the business service, don't know about consumer anymore.

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Thanks for sharing.

I'm also in the Bay Area and I use Comcast. I have my own modem (modem only device) and router, and I've never had any issues with running services such as Wireguard and OpenVPN among others. Comcast provides a public IPv4 address and doesn't block (most?) inbound ports (they may block some that are prone to abuse like port 25 for unsecured SMTP servers and the like, but never tested this).

I cannot speak to the Comcast provided equipment... ideally it would support modem-only/pass-through/bridge mode to pass the public IP to the WAN of your OpenWrt device, but otherwise you should be able to set a 'DMZ' or setup port forwarding as required if you cannot disable the router functionality. If you provide your own modem-only device, this will not be an issue, of course.

It is nice to know there is more than 3 openwrt users in california.

Just a note, comcast might or might not be a good ISP (no first hand experience). But DOCSIS certainly is somewhat dubious, these "jokers" considered it a good idea "hiding" data packets in 188 byte MPEG-2 "framelets" (each with 4 bytes overhead). I agree that this was a clever trick to get the whole thing jump-started in a way that was "compatible" with already deployed digital receivers, but it took them IIRC 16 years to offer an alternative doing away with this unnecessary encapsulation in version 3.1 of the DOCSIS standards (I could be wrong about this time line, so if anybody knows, please correct me).

I know that most often there is only a single "broadband" ISP available, but if I had viable options I would avoid DOCSIS. In fact that is what I do myself, 100/40 VDSL2* instead of 1000/50 DOCSIS 3.1**, However I do not use "linear" cable-TV.

*) With dynamic dual stack by default
**) With CG-NAT/ds-lite, full dualstack only available on request if one manges to convince them of really needing it.

I don't know exactly what Comcast does on the DOCSIS line, but the service quality has been good and reliable for me (despite the fact that I don't like the company, I honestly can't complain about the service itself).

@moeller0 - what is the practical concern that you have about the way the DOCSIS works (or did work)? Yes, the topology is shared more like the way old ethernet hubs worked vs switches, but this rarely presents an issue in modern networks. Is there some other specific issue/concern that could impact the service quality or other things?

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Nothing immediate, I am just not too big a fan of their development approach, and consider their planned low latency docsis work to be questionable engineering (driven less by analysis of hard data and more by hopes and wishes).
The shared topology aspect is something that does not really bother me, as I fully understand that sooner or later internet access traverses over a shared medium (e.g. for DSL the typical DSLAM's uplink is far smaller than the sum of all the contracted rates of all subscriber lines terminating on that DSLAM). And the biggest modern alternative [G|XG|XGS|NG|NG2]-PON* all use shared segments with a request-grant mechanism as well, so shared medium is going to stay with us.
So my dislike is more conceptual in nature and not linked to specific enumerated instances of problems, I just do not trust them to do decent engineering.

However, when I lived in southern CA a decade ago DOCSIS was the only broadband option available, and I used it, but now with acceptable alternatives I try to stay clear of docsis.

*) Compared to active optical networks (AON) passive ones (PON) have lower opex and capex, so at least for the mass market shared segments are going to stay with us for the next decades.

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At least isn't not driven by thoughts and prayers... lol

At times, I feel like the system (comcast's in particular) is cobbled together, but at other times I see it as a surprisingly well designed system, especially when considering the complexity of the scale and build-out speeds (i.e. takes years, so parts are using older tech, parts newer, etc... and it all has to work together).

I still use traditional CATV (yeah, old school) + broadband... so for me, one of the criteria is the ability to avoid using the ISP's gateway device. AT&T (fiber and/or DSL offerings in NorCal) requires this, so it would add complication to my network to bypass their equipment while still using the TV services. And given that DOCSIS has worked well for me in every location I've used it (4 different cities), I don't have any reason to be down on it (I did have FTTH in one city and they used IPTV without requiring a special gateway -- that worked well, too). My only truly miserable experience was with AT&T fiber/DSL (IIRC, it was FTTN, DSL to the home) in the Bay Area -- it was so bad I dropped their service and moved to Comcast within about a week.

Ah, over here, thanks to the EU's intervention, ISPs have to allow end users to bringvtheir own (compatible) gateway devices/routers and modems. So using OpenWrt on the primary router is possible pretty much independent of ISP and medium (coax, twiste pair, fiber, ...). This makes it much easier to switch ISP. Also the goal over here is to switch >90% of access lines to true fiber in the next 10 years, so DSL and DOCSIS are essentially transition technologies (with DOCSIS having admittedly more headroom for higher rates).

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I think part of the issue in my situation is the combined services of TV and internet from the same ISP, and AT&T's specific methods by which they deployed their service. I don't know how many other other fiber/DSL services have the same deployment model around the country and around the world, but it is annoying for advanced users. To be fair, putting aside any technology related considerations, the way AT&T does it actually tends to be a reasonable model for average users who want a single ISP provided box.

Comcast, of course, offers their own wifi router devices... they advertise them and the 'advanced' features like letting you set your own password :laughing:

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