02-18-2013 8:49 AM
While I didn't encounter this problem initially when I started up my Mcell a few months ago, it has now become a daily ritual that I hope someone here can help me with.
Motorola SB 6120 modem -> Netgear WNR3500L router -> Mcell
The Mcell is connected to the router with a pair of Netgear Powerline 200 Nano Adapters because my modem and router are located in the basement with no exposure to window for the Mcell to see a GPS satellite. The connection is good.
My Charter ISP connection is 30 mbps down and 4 mbps and is rock solid.
What's happening and what I've done so far:
Usually once a day I will no longer see the AT&T Mcell indication at the top of my iPhone 5. When I check my wife's iPhone 4S she has also lost the AT&T Mcell indication.
Turning the phones off and then on does not bring back the Mcell connection. Switching Airplane Mode off and then on does not bring back the Mcell connection.
The Mcell has all solid green lights when I go to check it after seeing the lost connection. If I power cycle the Mcell, the phones will then show an Mcell connection again until the next time they lose the connection which is usually once/day but not at any particular time.
I have the latest firmware on all devices.
When I check my router's admin page after a lost connection, the router indicates that the Mcell's IP address has not changed and it remains the same after power cycling the Mcell.
On the WAN page for my router, I have set the MTU size to 1492 and set the NAT Filtering to "Open" instead of "Secured". No improvement after doing so.
Suspicious of the Powerline Adapters, I tried disconnecting and reconnecting the Ethernet cable from the Mcell to the Powerline Adapter to mimic a temporary loss of connection to the router to see if that affected the Mcell connection. The Mcell connection was not lost.
I have not set any open ports or a static IP address for the Mcell yet. Is what I'm experiencing indicative of this solution? Does anyone have any other thoughts as to what try next?
I don't want to waste my time with an AT&T Level 1 tech support person because their suggestions are almost always worthless. I have better luck contacting user forums and that is why I'm posting here.
Thank God I was able to convince AT&T to give me a Mcell for free because if I paid $200 for it, I'd be very upset right now.
Thanks In Advance!
07-06-2013 10:53 AM
Sigh....update since my last post.
My dropped connection issue is still occurring just about every night in the wee hours of the morning and I am still able to reconnect by toggling the Airplane Mode on our iPhones when I wake up in the morning and find them disconnected.
I have been in contact with Customer Care throughout this problem and have traded a few phone calls with a technical support person.
They seemed to think that it is a competing signal issue between the Mcell and the local cell towers. They indicated that AT&T has been doing tower upgrade work in my area for the last three months and that it might be possible the changes have had an influence on what I'm experiencing. I do not see any increase in cell tower signal strength based on my iPhone's signal bars. Regardless, they decided to disable the hand-off feature to see if that would help. It did not. (Item of note: When I access the Manage Mcell website, it still indicates that the hand-off is enabled but tech support said that there is a problem with the website and have put in a ticket on it.)
I disagree with their assessment that this is a competing signals problem. My wife leaves her iPhone charging overnight at a location 20 feet from the Mcell while I take mine to our bedroom at night. Both drop the connection and have to be toggled to reconnect. If I've moved my phone to a location where the cell tower strength is greater and my phone switches to the tower, why does her phone switch and it hasn't been moved to possibly change the signal strength from the tower?
Why does this only happen at night? Our phones maintain connection with the Mcell throughout the daylight hours as they are moved around the house quite a bit. AT&T doesn't have an answer to this.
In talking to the tech support person, it is interesting that they have the capability to access logs for my Mcell and see various error codes. It would sure be nice if I could do that. You would think that if I can access logs on a $80 router to see what's going on that a $200 Microcell would have similiar capabilities. I guess they don't want customers to have that information.
Speaking of logs, I have just started monitoring my router logs to see what is going on regarding the Mcell. I assigned a static IP address to the Mcell months ago, so it makes it easy to look at interactions between the router and my Mcell.
I get two types of log entries associated with the Mcell. First, there is this kind:
[DHCP IP: (192.168.1.20)] to MAC
address 48:44:87:xx:xx:xx, Saturday,
Jul 06,2013 03:59:15
192.168.1.20 is the static IP address for my Mcell. I've blanked out most of the MAC address for security reasons but it is the Mcell's MAC. I'm not versed on router networks and DHCP, so I'm not sure what this log entry means or what is prompting it to occur.
The other kind is a lot more disturbing:
[LAN access from remote] from
192.168.1.20:443 Saturday, Jul
Again, the 192.168.1.20 is my Mcell and port 443 is for the HTTPS TLS/SSL. Again, I'm not sure what this log entry means. I would interpret it to mean that someone from the listed IP address is accessing the Mcell. I seen 3 of these in the last day. The IP addresses are from interesting places like Australia, China and Portugal. This worries me.
At any rate, I'm going to continue to monitor the router log to see if I can correlate a router/Mcell problem. AT&T said they were going to look at a few more things before sending me another Mcell.
To be continued....
- edited 07-06-2013 11:30 AM
I feel like we're old friends....
With my iPhone, I leave it in the family room when we go to bed. There's no reason for me to take it into the bedroom at night because we have a land line. It's about 35' from the router and indicates MicroCell connection when I turn it "off" at night and turn it back "on" when I leave for the day. If there is a disconnect at night, I never know it because M-CELL is always displayed. The same holds true for my wife's old Samsung, which she leaves in her purse so god knows where it ends up at night. Both LTE and WiFi are always enabled on my phone as well as handing off. I wouldn't totally disregard a tower issue because fluctuating tower output can affect the MicroCell and the iPhone (other phones as well). Houses can be funny in respect to signal quality and I don't think the signal bars on the phones are a real accurate indicator of signal strength/quality.
I too wish there was some sort of way to access the inner-workings of the MicroCell but Cisco/AT&T designed these so that it was near impossible to gain access to the AT&T network from the MicroCell without strict security protocols in place. If your MicroCell is behind your router then it should be safe but foreign addresses are a concern. It could be some sort of robo-dialing trying to find an open connection (of which your MicroCell is not) and "daytime" dialing from those countries would be nighttime over hear. Just a guess on my part though.
I forget but have you tried port forwarding? Does your ISP do any sort of maintenance at night which would cause you to briefly lose connectivity?
I've never looked at my router logs so maybe I should take a looksee and see if anything odd is there as well.
07-06-2013 12:03 PM
I've forwarded all the ports that are listed for the Mcell. I'm not showing any loss of connection to the internet in the router logs.
As I told the tech support guy, the only way to determine if there is a problem with the Mcell is to replace it. If the problem goes away, then it was indeed the Mcell. If the problem remains, then my problem resides elsewhere.
This is basic troubleshooting.....swap equipment, cables, parts....etc and see what happens. Given the Mcell's track record, it should be about at the top of the list but that would be a substantial cost to AT&T so we jump through hoops trying all the other stuff first before they have to pay to replace the Mcell.
While I'm typing this, my phones are off the Mcell again but this time I've got a flashing 3G light. This also happened yesterday about an hour before the ATT tech called me. He asked if I power cycled the Mcell to clear the 3G light. I said no, that this has happened before and it will reconnect with the phones on its own. He was surprised at my comment and said that it usually requires a power cycle to clear that. When he looked at my Mcell on his end he said there was an error code that said the Mcell had lost connection to the internet. After concluding our conversation, it eventually re-established connections to our iPhones.
I just hope they quit dicking around and send me a new Mcell so we can determine if it is the problem....
07-06-2013 1:55 PM
If the flasing 3G light was green, then you did lose connection. Whether it was the MicroCell, your router, ISP, or whatever is difficult to determine. I did forward your pm to me to one of the Forum Admins who in turn gave it so Support. I never get a response back because that's between the customer and Support but we did "hit" them twice with your issue. I would hope that they replace your MicroCell but that decision comes from someone higher the support ladder than the folks you are dealing with. Let us know what happens. Maybe I can push for a replacement from here. Can't hurt.
07-08-2013 8:32 AM
Pfffft...things are going from bad to worse.
Yesterday, the Mcell went to a flashing green 3G light and it would not complete to solid green. I tried a few power cyclings and a hard reset with a power cycling and still had the flashing 3G light, even after the Mcell sitting overnight. This morning, I deactivated/reactivated the Mcell. Finally, I was able to get a solid green 3G light. Toggled the Airplane Mode on the iPhones and I am connected......for now.
Concerning this competing signal strength issue, at what cell tower signal strength does a cellphone switch to the Mcell? On the lower levels of my house my iPhone shows one bar, which at that strength I have dropped calls or am unable to call at all. When I toggle the Airplane Mode and reconnect to the Mcell, I show 4 bars in the same location. I would think that if the Mcell signal strength is greater than the cell tower signal strength, it should switch the iPhone to the Mcell. It certainly should if the cell tower signal strength drops to one bar.
Again, the Mcell worked fine for three months and now this. I believe that the Mcell is defective and when the tech support guy calls me again (hopefully today), I am going to insist on a replacement.
What a pain....
07-08-2013 10:18 AM
I don't know what the signal strength has to be before a cell phone will begin to search for a better connection. Proprietary info I'm sure. I'll forward your post to one of the Forum Admins and see if that will do any good. I wish I could be more helpful.
07-10-2013 12:14 PM
I received my 3rd Mcell today. (Date code: 03/13; HW version 3.2).
Curiously enough, after deactivating/reactivating the previous Mcell, I did not find a lost connection this morning. One day fluke or was my issue resolved by deactivating/reactivating the Mcell? Maybe I should have tried that earlier but they didn't suggest it.
The tech support guy is suppose to call me back and see how things are going after I got the replacement Mcell. I'd like to be able to report what perhaps might be useful information to him and since I have 10 days to return the "defective" Mcell, I think I'll give the Mcell I am suppose to return a few more days of operation to see if the Airplane Mode toggling issue has gone away. I want to see if deactivating/reactivating the Mcell really resolved the problem.
Regardless, I'll keep the Mcell I was just sent and send the other back after my experiment is concluded.
07-10-2013 12:34 PM
You have a more recent hardware version than mine so it should work. I would keep it as long as you possibly can (maybe 8 days) before sending it back just to make sure. Deactivating/reactivating has worked for some in the past and for some reason I thought you had done that way back when. If I didn't suggest that, that's my bad and I apologize for that. But, if the new works, you have the most recent hardware version
07-15-2013 9:05 AM
Otto, we gotta stop meeting like this......
I received Mcell #3 on the 10th. I left Mcell #2 operating to see if activating/deactivating it solved the problem. After one day of no drops, Mcell #2 dropped connection to both iPhones the next night. I ditched Mcell #2 and activated Mcell #3 on the 11th. Mcell #3 was still dropping the connection overnight and I am able to reconnect by toggling the Aiplane Mode on the iPhones. On the 14th, I disabled the Mcell handoff feature but this morning (the 15th) I had lost the connection again and toggled Airplane Mode to reconnect.
So what do I know now? I would say that it isn't the Mcell that is causing the problem but I haven't heard from the tech support guy who was suppose to call me after I received Mcell #3 to see how it is doing. Without the error codes, I'm flying blind here. One would like to think that AT&T's Mcell system keeps a log of time-stamped error codes for each Mcell but who knows? Perhaps it only saves the last code. Without interaction with the tech support guy, I'm running out of things to try. Of course, when he called me, my Caller ID showed "Unknown" so I have no way of contacting him directly. Perhaps AT&T does that for a reason.
I keep coming back to the fact that I can leave my house with my iPhone and when I come back, it connects to the Mcell. Yet our iPhones can be in the house, have automatic handoff disabled, have 4-5 bars of signal strength to the Mcell and still lose connection to the Mcell by the morning.
The only thing I can think of trying is to take the Powerline adapters out of the equation. There could be a ground loop problem due to my house wiring or some other Powerline adapter issue that is causing the Mcell to momentarily lose its connection to the Internet. Perhaps when an Mcell loses connection in this configuration, due to its design, automatic reconnects to cellphones don't occur.
But then I ask myself, why just at night? Also, I've disconnected the Ethernet cable from the Mcell in the past for several seconds to mimic a lost connection and that hasn't duplicated this problem. I am also showing all solid green lights in the morning.
Still, I think it I need to verify if the Powerline adapters are the issue. Hard wiring the Mcell directly to my router isn't an option because of the location of my router doesn't provide the Mcell a good GPS view unless I string 30 feet of wiring to get the Mcell to a window location. One thing I can try is to hard-wire my Mcell to my WiFi repeater which is on the same floor of the house as my Mcell is. I don't know if this will work but it would eliminate the use of the Powerline adapters. I've got nothing to lose by trying it so I'll report back when I have more to offer.
Maybe toggling Airplane Mode isn't so bad after all......
07-15-2013 9:18 AM
Maybe I should put you on my Christmas Card list now
I've always been uneasy about the PowerLine Adapters. In theory, they should work fine. But I know they can be spotty if your in-wall house wiring is not trouble-free. It could be that the MicroCell is more sensitive to line condtions in that scenario. Being as this is the third MicroCell that has exhibited the same symptoms, that indicates to me it has something to do with your setup and not necessarily the MicroCell.
Can you use a GPS extension antenna? They aren't that expensive (at least most of them) and you could run a thin cable up to about 70' to a window (at least the last time I checked, which was quite a while ago).
- edited 07-15-2013 10:29 AM
An external GPS antenna could work but the fact remains that the Mcell needs to be centrally located in my house for adequate coverage. Putting it in the basement with my router would not cover the house even if I could get a GPS lock with an external antenna.
First things first though. I have connected the Mcell to my repeater and it is functioning. Powerline adapters are out of the system. The Mcell is in a different location than it was but it still close enough to a sliding glass door to maintain a GPS lock (hopefully). I have all solid green lights at the moment. I've got 4 bars in the basement.
07-15-2013 11:08 AM
07-17-2013 9:49 AM
While the problem with my first Mcell was somewhat different, I would agree that the issue with the last two Mcells does not now seem to show that they are at fault, especially after taking the Powerline adapters out of the system.
Since disconnecting the Powerline adapters and hard-wiring my current Mcell to my WiFi repeater, I have not had a lost connection over the past two days. This is very encouraging needless to say.
This house is over 50 years old and the AC wiring codes were not the same then as they are now. Specifically, the lack of adequate grounding on the AC outlets themselves. While it appears that the junction boxes are grounded, the AC outlets that are mounted in the junction boxes are not grounded to the junction boxes. In fact, the original AC outlets do not have a third prong (ground) to receive today's plugs. As I have gone through the house and painted rooms, I have replaced the AC outlets with the three prong type. However, grounding those properly has been a problem as access to a grounding wire has not been available in every case.
I had a satellite TV system installed in this house several years ago with multiple receivers and the installation guy couldn't get them to work initially. It turned out that having multiple receivers that didn't have a true common ground was the cause of the problem. Digital equipment like that is very finicky about ground loops. The problem was resolved by driving a grounding rod into the ground outside by the connection blocks for the satellite system and wiring the rod to the blocks, thus establishing a true common ground for all the satellite receivers in the house.
Remembering that incident now, it makes sense that digital communications (Powerline adapters) across my home's AC wiring could have similar problems. I do not have any knowledge concerning communication protocols between a Mcell and a router. One might think that it could be an issue with this particular router but since I have so many other items connected to my router without any problems, I have to conclude that the digital signal between the router and the Mcell is being corrupted somehow by a ground loop problem with the Powerline adapters.
The design of the Mcell circuitry apparently does not automatically recover its connection with the iPhones once the Mcell connection to the router is lost in this particular case. Simply unplugging the Ethernet cable to simulate a lost connection does not accurately mimic the problem since my iPhones maintain their connection when doing so. I would have to conclude that some bits are getting corrupted in the communication protocol between the Mcell and the router by the Powerline adapter's ground loop problem. The Mcell sees a lost connection to the internet and drops the iPhone's connection and in this case, the iPhones have to re-establish a connection to the Mcell through an Airplane Mode toggle in order to clear the communication corruption in the Mcell. This is conjecture on my part but it sort of makes sense.
At any rate, I don't think Powerline adapters are inherently problematic when used with a Mcell if the wiring system of the house is done correctly. Otto, since you are the keeper of the holy knowledge of the Mcell, I would suggest that you tuck this bit of information away in your troubleshooting database and add the question about Powerline adapter usage when responding to Mcell users with a problem like mine.
I'll post back after I get several more days of Mcell operation without Powerline adapters. If there is no repeat of the problem, then it has been solved.
07-17-2013 10:57 AM
Thanks for taking the time to post a very clear and concise of explanation of what you have done. PowerLine Adapters do work very well for most situations but you are correct, the house wiring needs to be very clean and modern. Older wiring may still be adequate for extending an internet connection and any momentary drop in current or grounding issues won't drastically affect your connection because the router can quickly recover and maintain the connection, but the MicroCell seems to be especially sensitive to line conditions with a much tighter threshold. This info will definitely go into my FAQ that I'm putting together. I also have a conference call with other ACEs and Support next week and this is one of the items on my agenda. In fact, there are supposed to be a couple of "MicroCell Experts" on the call so we'll see. Keep me posted.
07-23-2013 7:47 AM
Since removing the Powerline adapters from my system and hard-wiring the Mcell to my WiFi repeater, I have had zero dropped connections for the last eight days. I have no doubt now that there was some sort of packet corruption going on while using the Powerline adapters which was the source of my problem. Needless to say, the adapters have gone back in their box for now.
If anyone wants to buy a pair of Netgear Powerline Nano 200 adapters, I'll make you a really good deal.