3G microcell / Comcast Surfboard sb5120 / linksys e4200 - 3G light keeps flashing

Contributor

3G microcell / Comcast Surfboard sb5120 / linksys e4200 - 3G light keeps flashing

Hey guys,
I have a Comcast connection wi a motorola surf board cable modem and a linksys e4200 router' but the 3G microcell is unable to connect to the AT&T network even though It has a solid gps lock. I tried connecting the microcell to the modem in priority mode (router disconnected so I could troubleshoot) and the 3G light still didnt connect.

Have any of you faced this? Could it be an issue with Comcast?

I've done everything from opening UDP and TCP ports, disabling the router firewall, giving the microcell a static ip thru the router. I'm at a loss in terms of figuring out what to do next. Could this unit be a lemon?

Thank you for your help!
J

P.S. My Comcast downstream speed is about 18mbps and up is about 3mbps
Message 1 of 9 (1,720 Views)
ACE - Master

Re: 3G microcell / Comcast Surfboard sb5120 / linksys e4200 - 3G light keeps flashing


jatin.ahuja wrote:
Hey guys,
I have a Comcast connection wi a motorola surf board cable modem and a linksys e4200 router' but the 3G microcell is unable to connect to the AT&T network even though It has a solid gps lock. I tried connecting the microcell to the modem in priority mode (router disconnected so I could troubleshoot) and the 3G light still didnt connect.

Have any of you faced this? Could it be an issue with Comcast?

I've done everything from opening UDP and TCP ports, disabling the router firewall, giving the microcell a static ip thru the router. I'm at a loss in terms of figuring out what to do next. Could this unit be a lemon?

Thank you for your help!
J

P.S. My Comcast downstream speed is about 18mbps and up is about 3mbps

Is the Motorola "modem" in bridged mode? Do you get any  "double NAT" error messages with your router? Someone else I know has Comcast and they're having a difficult time connecting and getting a constant 3G light. They too have done all of the port forwarding etc.

___________________________________________________________

MicroCell Technical Guide by Otto Pylot


I am not an AT&T employee. For additional help, please send a PM to ATTCustomerCare

*The views and opinions expressed on this forum are purely my own. Any product claim, statistic, quote, or other representation about a product or service should be verified with the manufacturer, provider, or party.
Message 2 of 9 (1,702 Views)
Contributor

Re: 3G microcell / Comcast Surfboard sb5120 / linksys e4200 - 3G light keeps flashing

Unfortunately I can't figure out how to check that, I don't know how to access the modem, I tried 192.168.100.1, but that's not the modem IP.

Did your friend have any luck? Maybe I should buy a modem from best buy and replace this one.
Message 3 of 9 (1,698 Views)
ACE - Master

Re: 3G microcell / Comcast Surfboard sb5120 / linksys e4200 - 3G light keeps flashing


jatin.ahuja wrote:
Unfortunately I can't figure out how to check that, I don't know how to access the modem, I tried 192.168.100.1, but that's not the modem IP.

Did your friend have any luck? Maybe I should buy a modem from best buy and replace this one.

I would contact Comcast first before you buy a new modem. They should be able to tell you the modem is bridged or not. Push them if they're not cooperative. Look up the modem online. You may be able to find the spec sheet that will tell you how to access it.

___________________________________________________________

MicroCell Technical Guide by Otto Pylot


I am not an AT&T employee. For additional help, please send a PM to ATTCustomerCare

*The views and opinions expressed on this forum are purely my own. Any product claim, statistic, quote, or other representation about a product or service should be verified with the manufacturer, provider, or party.
Message 4 of 9 (1,696 Views)
Guru

Re: 3G microcell / Comcast Surfboard sb5120 / linksys e4200 - 3G light keeps flashing

I have Comcast, a surfboard and separate router and have all 4 lights on solid. We still have problems with call delays, but we don't have any problems getting the thing online.

 

We have a SB6120, which is the latest Motorola DOCSIS 3.0 "dumb" (no built-in router) cable modem. Judging by your model number, it looks like you just have the previous generation of the same thing, which ought to be fine.

 

You might try looking at the configuration of your E4200 to see if it's set to block fragments. Another posting nearby said that disabling fragment-blocking was the solution to their problem.

Message 5 of 9 (1,671 Views)
Contributor

Re: 3G microcell / Comcast Surfboard sb5120 / linksys e4200 - 3G light keeps flashing

Thank you for your help! After spending quite some time with ATT, I decided to swap the Micro Cell with a new one. I'll give that one a try tonight. From what I remember, I've totally turned off the firewall etc. capabilities of the E4200.

 

I'll post an update on my story once I try out this new device. Thanks guys!

Message 6 of 9 (1,667 Views)
Scholar

Re: 3G microcell / Comcast Surfboard sb5120 / linksys e4200 - 3G light keeps flashing


nsayer wrote:

I have Comcast, a surfboard and separate router and have all 4 lights on solid. We still have problems with call delays, but we don't have any problems getting the thing online.

 


I'm wondering if after a certain amount of time with no activity if the VPN tunnel is closed automatically.  When a call is made/received, it then sets up the VPN tunnel again which results in the delay we're experiencing.  I'm grasping at straws here but we've all seen the call delays.

Message 7 of 9 (1,656 Views)
ACE - Master

Re: 3G microcell / Comcast Surfboard sb5120 / linksys e4200 - 3G light keeps flashing


bkmjk wrote:

nsayer wrote:

I have Comcast, a surfboard and separate router and have all 4 lights on solid. We still have problems with call delays, but we don't have any problems getting the thing online.

 


I'm wondering if after a certain amount of time with no activity if the VPN tunnel is closed automatically.  When a call is made/received, it then sets up the VPN tunnel again which results in the delay we're experiencing.  I'm grasping at straws here but we've all seen the call delays.


And to confuse things more, we have no call delays at all on iPhone 3GSs or other cell phones. Sounds to me like they have regional or service area servers and not all are on the same page. Typical.

___________________________________________________________

MicroCell Technical Guide by Otto Pylot


I am not an AT&T employee. For additional help, please send a PM to ATTCustomerCare

*The views and opinions expressed on this forum are purely my own. Any product claim, statistic, quote, or other representation about a product or service should be verified with the manufacturer, provider, or party.
Message 8 of 9 (1,648 Views)
Highlighted
Contributor

Re: 3G microcell / Comcast Surfboard sb5120 / linksys e4200 - 3G light keeps flashing

Hi,  I am having a similar problem with the microcell we have set up at work and our Comcast Buisness IP Gateway which is an SMC 8014.  Did you end up having luck with the new replacement unit?  Did you have to have them put your modem in bridge mode?  Any info would be helpful.  I have tried opening the ports on our Netgear router as well as directly connecting the microcell to the Comcast router/modem and still can't get the microcell to work.  I do have all the lights except for the 3G light come on solid but the 3G light will only flash for a minute or so and then go out.  Then it seems like the router will reset itself after a while and go through the activation process again.

 

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