Time Capsule and Xfinity Routers

Question

I had been using a Time Capsule for a couple years: first with Comcast, then with ATT Uverse, and then back to Comcast. Last year the Time Capsule drive died so I bought a new 2TB Time Capsule. I have been having a recurring problem with this new Time Capsule where every day (usually between Noon and 4PM) the green light turns auburn, the Time Capsule seems to reset itself for 90 seconds or so, and then goes green again. Sometimes it happens late at night 2amish. This usually happens once per day, which in theory shouldn't be a major problem but when I work at home Noon-4PM is a problem. I never had this problem with my old Time Capsule or if it did the same thing it was resetting very late at night when I was asleep.
I called Apple tech support. They said it was a problem with the wifi on my Xfinity modem conflicting with the Time Capsule and I needed to get Xfinity to turn the Wifi off on the modem, which is a SMCD3GNV model. Xfinity told me that I can just use the button on the modem to turn off Wifi. I did. Same problem with the Time Capsule so I called Apple again. The next time Apple told me to have Comcast disable SSID on my modem and open all ports on the modem. Comcast disabled SSID but to have them talk me through opening all ports required paid customer support, and to be honest, I've not really found their service reps to be that smart. I am still experiencing the same problem with the Time Capsule (every day). I should add that the Wifi light is unlit on the Xfinity modem but when I login to the admin interface via my Web browser, I still see Wifi checked.
So, I have 3 questions:
(1) I saw in another thread that there are problems with the latest Time Capsules. Maybe this is a single user problem. Or maybe it is a larger problem. If it is a larger problem, this Time Capsule is still under warranty. I could return it and just use a WD drive via Time Machine and turn the Wifi back on on the Xfinity for a lot less money. But if this was a single user problem then that leads to (2) and (3)
(2) Do I need to turn off the Wifi in the Xfinity admin Web interface since I still see a green checkmark next to Wifi? The signal name no longer appears when I click on the airport icon at the top of my screen, so I assume that the signal is off, but if I need to turn off in the admin Web browser window, how do I do that?
(3) Is there a way for me to open all ports via the Xfinity admin Web interface? If so, how do I do that?
Thanks.

Answer 1

If you have phone service via the xfinity modem you may be stuck with using it in router mode. It depends how phone service is being handled. Nor do you need to do any port opening to the TC.. the TC MUST be in bridge mode..
I downloaded the manual for the SMC
http://media2.comcast.net/anon.comcastonline2/support/userguides/SMCD3GNV_User_G uide.pdf
but it has no details at all.. if you know where there is a more detailed user manual with full guide to the setup of the router please give me the URL.
In bridge there are no ports being blocked. There is one and only one router in such a newtork, the SMC.
The only reason to open ports in the xfinitiy is because both the xfinitiy and the TC are in router mode.. this is the wrong setup at any time.
If you want to pursue the issue.. then you need to be prepared to do a bit of work on the settings of the TC.. and study the logs to see if you can find where the failure occurs.
But you need to know the issue is not the SMC .. so if the TC is off.. then there are no dropouts???
If that is the case the TC needs to firstly have a full factory reset.
The quick method of factory reset.
Power down the TC.
Hold in reset. and keep holding it in. Be Gentle! It is a tiny surface mount switch with a plastic lever.. Attempting to push it out the other side of the TC will not make the switch turn on better.
(I fix TC and have several reset levers bent over and jammed or broken off).
Power on the TC.. remember with the reset held in.. this needs three arms.. a friend or power switch you can get to with your feet..
Keep holding in reset for about 10sec until the front LED flashes rapidly.
Release reset and wait .. the boot will be slow as it deletes previous setting.. only from router side and pulls out the factory defaults. No files are deleted on the hard disk.. but the name of the TC may change.
Redo the setup with all SMB compatible names.. that means.. short.. 2-20 characters, no spaces and pure alphanumeric.
Use fixed wireless channels.. this is really important to keep the SMC separate from the TC. So fix channels on both device.. is what I would recommend. There are only 3 channels that do not overlap.. 1, 6, 11 at 2.4ghz .. set one device to 1 and the other device to 11.
5ghz is less of a problem and the SMC doesn't use it.
Now using a 5.6 utility you need to keep track of the log in the TC and watch when the drop out occurs.
There is also a wireless check in the utility.
I do recommend you set the DCHP server in the SMC which is handling the whole network, to a very short lease time.. eg 20min.
Give me some screen shots of the setup of the TC as you have it now. Particularly the wireless and network setup.