ARRIS SURFboard T25 DOCSIS 3.1 Gigabit Cable Modem, Comcast Xfinity Internet & Voice, Two 1 Gbps Ports, 2 Telephony Ports, 800 Mbps Max with Xfinity Internet Plans,Black

Needed to up grade from my previous modem which was working well but getting a bit long in the tooth. The install was straight forward and pretty easy to activate my internet setup and connection....but trying to a get my phone activated was a real pain.Spoke with Comcast to verify my MTA and HCF mac address' and to get my dedicated phone line working, no problem. Comcrap wasn't able to get a dial tone after several attempts, so they suggested I contact the modem mfg. that it might be defective.So I called the mfg, they were very helpful with trying to help me resolve this issue, but in the end they said to just return it for a replacement, which I did.Got the second modem very quickly and installed it...same thing, no phone connection. Called Comcast and went through the whole thing again with them, they ended up telling me they were sending this to the next level of their tech support and would be back in touch in several days.....guess what, no call back after 3 days.Called Comcast back again for the 4th time and spoke to the first person from tech support that picked up the phone. Had a feeling this was going to go badly, but to my amazement she was able to do what 3 other calls to tech support couldn't, get my phone service, which is provided by them, connected.I can highly recommend the ARRIS T25, it is really easy to install, unless you have phone service from Comcast, it runs my max internet speed easily, is compatible with Comcast specs and will save you the $14/mo rental charge if you use a Comcast modem.Excellent product.... I hope this ARRIS model lasts as long as my previous one.A side note, this functions as a modem only with phone service, it's not a modem/router combo, so no WiFi. I use a separate router for my Wifi connections.

I installed the Arris T25 modem about a week ago. It replaced an Arris Surfboard 6190. I bought the T25 to use Xfinity Voice which is part of my plan but which I never used. The modem has been operating since installation without any incidents. Internet download speeds went from 600Mbps to 900Mbps. The telephone line has performed perfectly.Installation was not as straightforward as I would have liked. Since I don't have an exceptionally strong cellular signal where I live I first tried connecting a laptop directly to the modem and using the Xfinity activate webpage from a browser. I got nowhere trying that. I always ended up back on a webpage that told me to download and use the Xfinity app on my smartphone. Despite the weak cell signal I decided to try the Xfinity app from my phone. Scroll down in the app to where it says, "Got new equipment to set up? Activate now." It worked fine. The app only asks for the modem's HFC MAC ID, not the MTA MAC ID. After a few minutes of watching the lights on the modem cycling the app reported that the modem was online and provided the telephone number assigned to it. That was it - internet working, telephone working, no call to Comcast required. I connected my Asus router to the modem and I was good to go.Update: A frequently asked question is whether the modem can be connected to extension phones in the home. The answer is yes. However, my first try wasn't successful. I connected the modem to a wall jack that's connected to all of the extension phones after first disconnecting the phones from my current landline supplier at their demarcation box. The phone light on the modem started blinking as if the line was in use, but it wasn't. The displays on my extension phones also showed "Line in Use." I disconnected the modem from the phone jack to think about what the issue could be. A few days later I tried again but this time thought to disconnect a printer/fax from its phone wall jack. All of the extension phones now worked perfectly. I'm not sure why the printer/fax would cause a conflict when it was not in use, but all of the extension phones are working fine now. I can live without the fax if I have to.Update March 14, 2024: I think it's helpful to update reviews after a product has been in use for some time. I've been using this modem for internet and phone since November of 2022, and its performance has remained absolutely solid. I have not had to reboot it once. Very happy.

We purchased this modem specifically because it's certified by Comcast for its gigabit Xfinity internet service. It also incorporates an eMTA (telephone adapter) for the Comcast VoIP / landline service.Installing it was easy and simple enough; however, getting Comcast to properly provision it took several days and numerous provisioning hits and power cycles.Comcast says it cannot see the anything inside the modem including the signal levels, signal-to-noise ratios or anything behind the password protected advanced page.The modem has slow upload speeds and will reboot itself almost every night. This knock everything in the house off line and makes cloud backups frequently crash. The modem reboots do not correct the bad internet service.There are plenty of similar documented problems on Comcast's support forums and elsewhere.We had no problems with an older gigabit modem and a separate eMTA, but nothing but problems with this Arris T25 modem.I see plenty of these being sold at the Amazon warehouse at discounted prices, and now I understand why.Arris tells us that the upload signal levels are out of spec. Comcast says everything is OK. I tend to agree with Arris, based on the error logs, frequent reboots, and uploads hanging.Very frustrating to have a Comcast certify and recommend this modem, but not be able to see what's going internally. And then to blame the vendor they recommend.Whatever Comcast may recommend -- I DO NOT recommend this Arris product as there is no way to determine if defective chips are present or not and no way to get a reliable, stable, internet connection."Lost MDD Timeout" error message causes the reboot -- every day at 23:30 or so.

Once installed this product seems to be working very well (over 3 weeks now). However, installation and instructions were not straightforward. This Modem is designed for internet as well as voice (landline VOIP). Unknown to me, this requires two (2) MAC addresses - one for internet and one for voice. To install you will first need to call Xfinity to register the Modem. To do this you will be required to provide both MAC addresses - I only provided one (voice) which resulted in Xfinity not recognizing the Modem. I had to get the Xfinity technician to come in to help with the installation. (I tried calling ARRIS Tech Support but no one picked up.) After clearing the mix up with the MAC addresses getting internet service was still not straightforward as the Tech had to dig into his bag of tricks before internet and telephone services were reliably established. Service has been working reliably since that time. Kudos to the Xfinity Tech. The efficacy of ARRIS Tech Support is an unknown at this point as they were not used.

I've had this modem for a couple of months now and it has been performing great, consistently able to get the maximum bandwidth for my plan from Xfinity (350Mb/s). (I'm sure it will perform to deliver gigabit speeds if the internet plan allows that as well, but I just haven't personally seen that.) No outages*. It was very easy to install, just hooked up the coax cable from Xfinity to it, and the Ethernet cable from it to my router. I started on the Xfinity web app for finishing the provisioning and set-up but unfortunately Xfinity had some bad data on my account, the app showed a modem that was from years ago, not the one I was replacing with this, so it kept throwing errors when I tried to go through the steps to provision the new one. So I did have to call Xfinity on my phone and complete the provisioning that way. It was quite easy, just 5 minutes on the phone, gave the tech the cable modem id number and it was up and running shortly thereafter.(*) I am giving this 5 stars despite an initial couple of glitches with it. In the first 2 days that I had the modem, it twice turned off by itself and, strangely, would not turn on again until I disconnected all cables, and then reconnected them, and then turned on the power. (Until I disconnected the cables and reconnected them, simply trying to toggle the power caused the LED lights to flash a few times and then stop.) This was very annoying but it only happened those two times and has not happened at all in all the time since then that I've had the modem and it has performed with rock-solid stability. I'm not sure what those glitches were caused by, possibly some provisioning issue at Xfinity still settling down? Or else just a total coincidence and some other event (power spikes or static discharges somewhere happened at those times? Regardless, since it has been performing without any problems at all for an extended period now, I feel sure enough to give this a 5-star rating.