Download speed problems with Time Capsule

I upgraded to high speed modem (Arris SB6190) leads to the Time Capsule but still only receiving 50 mbit/s. This model can download up to 1.4 Gbit/s. Is the Capsule the problem?

Unfortunately, the Arris/Motorola SB61XX-series of modems have been found to be incompatible with the AirPort base stations. The typical issues when these are paired is either loss of Internet connectivity or poor data transfer rates over the WAN/LAN link. Neither device is bad in themselves, but they just don't "play nice together."

Can i insert a router in the network and use the existing time capsule to backup my files.

Yes. However, you will need to connect the Time Capsule back to this other (non-Apple) router by Ethernet in order for it to work properly. You then have the choice to configure both devices for a roaming type network.

Yes, you can use a different brand router and use the TC still plugged in by ethernet for backup. Be aware some people do have issues with this setup and Apple do not recommend it.. for some it works fine.. so a bit of trial and error.

I would be trying to find the problem. A Gen4 TC should be able to handle internet at speed above 150Mbps.

Did you test with computer plugged in by ethernet and wireless turned off?

Your issue could be wireless only??

Yes, A1409 is Gen4 and is last of the flat ones.

Would you suggest a model/router combo and insert before the TC.

Choosing a different modem or modem router is up to you.

Have you plugged a computer directly into the modem by ethernet and tested the speed? You don't mention doing it and I think it is essential to prove you are getting the stated speed.

My preference would be to keep the current modem and by a new router.. you can buy from a huge range of price points whatever suits your budget and needs. But I recommend the AC1900 type like Asus RT-AC68U.

Just a comment .. if the issue is as per Tesserax, although there are issues with the Apple Airports and the single port cable modems from Arris (Motorola). It did tend to affect the next model, AC airports, a lot worse than the earlier ones.

I would downgrade the firmware on the TC and see how it goes.. after a factory reset and simple configuration.

Also the IPv6 setting is crucial to get right. In your area, check if Comcast is using IPv6.. I think it is pretty universal now. There are a couple of settings for IPv6 Internet in the TC that you must get right.

Comcast did have IPv6 setup document for Apple routers but they pulled it for some reason. Most of the info will relate to the later models but the earlier ones should be fine on firmware from 7.6.1 onwards. One of the guys here should be able to help you.. I am not in the US, not on IPv6 and barely on broadband. Even 50Mbps sounds an impossible dream to us.

http://forums.businesshelp.comcast.com/t5/IPV6/Using-the-Apple-Airport-Extreme-w ith-Comcast-Native-IPv6/td-p/28456

http://forums.businesshelp.comcast.com/t5/Equipment-Modems-Gateways/Configure-Na tive-IPv6-with-Apple-Airport-Extreme/td-…

As far as AirPort compatibility is concerned, I am only aware of the issues with the Arris/Motorola SB61XX-series ... so most other modems should be fine. I have had good experiences with both Cisco and Zoom modems. However, whatever modem you choose be sure to check with your ISP to make sure that they support it as well.