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ZyXEL P660HN-51 Overview

Do you currently have a CenturyLink connection in your home or office, or are you planning to subscribe to one? Wondering if ZyXEL P660HN-51 is a viable choice to pair it with? If yes, this ZyXEL P660HN-51 review should be helpful, wherein a detailed analysis of its speeds, consistency, coverage, etc., is presented.

Before I start reviewing this ZyXEL modem router, let’s have a quick glance at the upgrades it brings over its predecessor, Zyxel P-660HN-T1A. The latest model comes with greater coverage, speed, throughput, and additional ports. Continue reading to find out more!

ZyXEL P660HN-51 Specs

Ports1 x DSL + 4 x Ethernet + 1 x LAN/WAN + 1 x USB 2.0
Modem-Router ComboYes
Built-in Router Speed300 Mbps
Wireless StandardWi-Fi 4
Wi-Fi RangeApprox. 1,800 Sq. Ft.
Connections CapacityApprox. 20 Devices
App SupportYes
QoS FunctionalityNo
NAND StorageUnknown
Dimensions7.44 x 5.2 x 1.65 inches
Weight0.80 pounds

ZyXEL P660HN-51 Review

I used the ZyXEL P660HN 51 for 15 days by pairing it with a top-tier plan by CenturyLink. Over the course, the unit is put into several scenarios to determine its utmost capabilities and potential. Now, it’s time to present my honest take on this modem router combo across diverse parameters. Let’s go!

Note: If you’re unaware of what a combo device means, check out the differences between modem router combo and separate devices.

ZyXEL P 660HN 51 Speeds


The ZyXEL P 660HN 51 gateway is based on ADSL2+ standards that support high speed and deliver stable connections across the day. And theoretically, the maximum throughput of the unit is 450 Mbps for downloads and 70 Mbps for uploads.

Now, the ZyXEL modem router with a single 2.4GHz band can deliver speeds up to 300 Mbps and decent wireless coverage. With 802.11n support and backward compatibility with 802.11b/g, you can even run low-speed plans. Also, with the integration of 2×2 MIMO technology, there’s an improved signal range, lower power consumption, reduced bit errors, and reduced interference.

As soon as I paired it with CenturyLink 940 Mbps plan, I hooked up my Smart TV directly to the unit and found the speeds pretty impressive. The download speeds outstretched to 380 Mbps, whereas the maximum upload speeds clocked at 50 Mbps.

On the other hand, wireless speeds on my devices reached up to 200 Mbps, which made simultaneous audio/video streaming and online gaming much smoother and faster.

ISP Compatibility & Service Plan Suitability

ZyXEL P660HN-51 is a CenturyLink-exclusive modem with limited ISP compatibility that works only with CenturyLink internet plans. Although with ADSL2+ and 802.11n wireless support, it’s an apt choice for plans between 400-940 Mbps plans. Besides, it’s backward compatible, meaning that running low-speed plans is also an option.

Design & Connectivity

The chassis of P660HN 51 is rather basic but seems very practical and functional. Its dimensions are tagged at 7.44 (W) x 5.2 (D) x 1.65 (H) inches, and the device is much lighter than it looks, weighing less than a pound. Plus, with a vertical orientation and flat base, it stands still without wobbles and doesn’t take up much of your space.

There are no Gigabit ports, but I wasn’t disappointed with the speeds I got connecting with the Ethernet ports. There are four of them, so you can connect multiple devices simultaneously and receive greater speeds. Besides that, the ZyXEL ADSL modem also hosts a USB 2.0 port to which you can connect varied peripherals, including a printer, an external storage device, and more.

Hardware & Performance

Although there’s no mention of hardware specifications, there were no visible lags or slowing down when connecting with multiple devices, except for the network dead zones at a few places in my two-story house.

I’ve extensively used it with an HD TV, a desktop, and a couple of smartphones. So, rest assured you have got a powerful processor supported by a decent RAM. However, the ZyXEL gateway heats up when I ran multiple sessions of streaming and gaming, but that didn’t affect its performance a tad.

I could complete all missions of Red dead redemption at a stretch in decent graphics settings without any lags or network slowdown. However, putting a heavy task load on your modems is not viable unless there’s an important project to complete.

ZyXEL P660HN-51 Setup

Setting up P660HN 51 is rather uncomplicated and hassle-free. Connect the device to a laptop, a webpage opens up, enter your username and password, and viola! You’re connected and ready to get-go with the fastest of speeds. Even my grandpa could finish setting it up in less than 10 minutes without my expertise.

Additional Features

The 660 series modem has enhanced security that protects your traffic from WAN to LAN. With the implementation of two Ethernet firewalls, SPI and NAT, the device can identify, manage, and blocks malicious content and applications.

Furthermore, its wireless connection features WPA-2/WPA/WEP, and a hardware WPS button that allows customers to set up the device with a single click. With these, you can set up and deploy a secure wireless network.

Miscellaneous Information:

Default Password1234
Current Firmware1.12(AADW.7)C0
Login Page
ZyXEL P660HN-51 ManualView

Pros & Cons


    • Budget-friendly 
    • Secured from malicious contents
    • Multiple ethernet ports
    • Decent speeds
    • Easy to set up


    • Not as fast as dual bands
    • Modem heats up

Frequently Asked Questions

How fast is the ZyXEL P660HN-51?

ZyXEL P660HN-51 modem router is fast enough to handle most of your tasks like video conferencing, casual gaming, and browsing with ease. However, it is much slower than modems with DOCSIS technology support and routers with dual bands.

Is ZyXEL P660HN-51 a modem and router?

Yes, it is. So, you can connect your device directly or wirelessly, whichever is convenient. However, it would be feasible to connect your device directly to the modem to get higher speeds.

How many devices can ZyXEL P660HN-51 support?

With four Ethernet ports, you can connect up to four devices directly to the ZyXEL ADSL modem, while wirelessly, 8-9 devices can be connected and run simultaneously.

Can I replace the CenturyLink modem with my own?

Yes, you can. Just look if the third-party modems you are looking at are certified by CenturyLink. Or you can check my review of top CenturyLink-approved modems to make an informed purchase decision.


It makes sense to pair ZyXEL P660HN-51 with high-speed plans to get the most out of it. There’s a technical team at CenturyLink that’s always proactive in providing solutions to your queries and problems. But its compatibility and inferior technology make it a harder choice.

If you are a CenturyLink internet subscriber like me, the unit’s performance and CenturyLink support make a strong case to become an inevitable part of your home’s internet setup. So, go for it.

ZyXEL P660HN-51
ZyXEL P660HN-51
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