Sorry for the long post but I would be forever grateful to anyone who can help me understand modems and how to choose the right one, to match a router's specs.
So I moved into a new house and decided I'd upgrade for the first time to a 100 mbps download speed internet plan (10 mbps upload) from Cox. Not really knowing much about internet, and after hours of research, I decided
to buy a Trendnet AC2600 TEW-827DRU router for $110. It's dual-band: 800 mbps advertised speed on its 2.4 GHz band, and 1733 mbps advertised speed on its 5 GHz band. According to pcmag.com, they tested actual speeds on its 2.4 band at 108 mbps in the same room and 75.3 mbps at 30 feet. On the 5 GHz band, they tested actual speeds at 590 mbps in the same room and 260 mbps at 30 feet. My goal was to choose a router that will get me as close as possible to 100 mbps speeds on both bands for several devices throughout my 2 story house (while taking price into consideration).
I had assumed that matching a modem to a router would be simple. I thought it just needed to have a gigabit port, be dual band 802.11 AC, DOCSIS 3.0 or higher, and certified by Cox. After choosing my router, I discovered that Cox has a "Cox Certified Modems List (with actual modem models listed)." There are also modems on Newegg that state they are Cox compatible but are not on this list. After looking at these modems, I've become confused again and have some questions.
I don't want the modem to bottleneck the throughput wireless speeds of the Trendnet AC2600 router. I learned modems have bonded channels, for instance 8x4, which translates into 344 mbps download speed and 172 upload speed. Are these 8x4 speeds theoretical or actual? Is a 8x4 modem not going to bottleneck the speeds I can get (like close to the speeds as tested by pcmag) with the Trendnet AC2600 router? Or do I need a higher channel count like 16x4?
A few of the modems on newegg have AC numbers or list that they're dual band capable. I thought the router is what handles being simulatenously dual band. Does one's modem also have to be dual band (if so, I don't know how to tell if a lot of modems are dual band as their specs don't say)? Why do a few of the modems have AC numbers (a lot of them don't)? Is this relevant? Like will an AC1600 modem bottleneck my Trendnet AC2600 router?
For instance, the Arris SBG6700 modem has AC1600 in its title and says it's dual band (I'm also pretty sure it is just a modem and not a router/modem combo unit as this question was specifically asked and answered about the model on amazon). But most of the modems on newegg do not mention if they are dual band and don't mention an AC number in the modem's title or specs.
Models I've considered on the Cox Certified Modems list:
-Arris SBG6700, AC1600, dual band, 8x4, for $100
-Netgear C6300BD, AC1900, dual band, 24x8, for $50 USED
-TP-Link CR500, AC1200, no dual band info, 16x4, for $130 (this model is 16x4 yet AC1200 while the Arris SBG6700 is 8x4 but has higher AC1600-confusing)
-TP-Link CR700, AC1750, dual band, 16x4, for $155
Models I've considered not on Cox's list but model's listing says is Cox compatible (none of these models have AC numbers nor say whether they're dual band or not):
-TP-Link TC7620, 16x4, for $69
-TP-Link 7610, 8x4, for $40
There's also the Arris SB8200 for $189, 32x8, and DOCSIS 3.1, but I hope I don't need something with this high of specs and this expensive (I thought after choosing my router that the modem would be cheaper).
It'd be great if someone can help me with these questions. The ultimate question is can someone recommend a modem at the best price, preferably new, that won't bottleneck the speeds of the Trendnet AC2600 TEW-827DRU router (I ultimately don't understand the specs I need of the modem)?
Also, pseudo random question, why do BOTH routers and modems have ethernet LAN ports? Do they serve the exact same purpose?
Thanks very much to anyone who can steer me in the right direction, would like to have wifi in my house soon, just need to buy the dang modem now.