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LarATV's profile

Tutor

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6 Messages

Monday, September 21st, 2015 7:33 PM

Microcell recently stopped working; Network light won't stop flashing green

I've had a Cisco DPH-154 for nearly a year now.  It worked perfectly in my office until Wednesday evening, September 9.  Now, and despite hours on the phone with AT&T and many hours of investigation by network experts in my office, we cannot get this thing to work again.  I've reset and power cycled the thing many times.  The power, Internet and GPS indicators always end up Green, but the Network indicator just flashes Green - and folk are unable to connect to the MicroCell to make or receive calls.  The MyAT&T website even says that Activiation is complete:

Capture.JPG

About a month ago, my company implemented Zscaler, but the MicroCell seemed to work just fine until 11 days ago (well after the Zscaler implementation).  My company gets WAN from OBS over NBIG.

 

I've taken it home and connected it to my personal home network, and all is well - but it's my office where the signal is so poor.  Despite what the MyAT&T MicroCell setup page shows above, AT&T says that the unit is “Unable to establish a connection on port 4500 due to no response.”  We believe this is something related to the unit NOT responding to ICMP echos.  But when we blocked those on our home routers, the unit still came up just fine and we were able to connect to the MCell signal - so we believe this was a red herring.

 

So, of course, I'm thinking that it's something that has changed in my company network.  And as I've said, some very smart network experts in my office have spent hours poking at this thing, but to no avail.  All of the ports indicated in the AT&T documentation are open.  There are, of course, more than one switch/router between the MicroCell and the WAN.  I've read Otto's guide, and ran some of the tests suggested (output below) but nothing seems to help. 

 

Any ideas where to look next?

 

www.speedtest.net: 

 

Capture.JPG

 

8x8 VoIP Test:

 

Speed test statistics
---------------------
Download speed: 10301 kbps
Upload speed: 718 kbps
Download consistency of service: 61 %
Upload consistency of service: 13 %
Download test type: socket
Upload test type: socket
Maximum TCP delay: 145 ms
Average download pause: 2 ms
Minimum round trip time to server: 90 ms
Average round trip time to server: 97 ms
Estimated download bandwidth: 58299 kbps
Route concurrency: 5.6593556
Download TCP forced idle: 91 %
Maximum route speed: --

VoIP test statistics
--------------------
Jitter: you --> server: 7.1 ms
Jitter: server --> you: 2.0 ms
Packet loss: you --> server: 1.8 %
Packet loss: server --> you: 0.0 %
Packet discards: 1.6 %
Packets out of order: 0.0 %
Estimated MOS score: 2.6


General information
-------------------
IP address: 104.129.196.126
Local time: Sep 21, 2015 1:19:59 PM
Test server: http://voiptest.8x8.com:82/

 

Of course, if AT&T and the FCC can get on the same page with respect to cellular calls over WiFi, I might just be able to forget the MicroCell.  Then again, it's the FCC.....

 

2 Attachments

Community Support

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15.2K Messages

9 years ago

Hi there! @LarATV thanks for posting your concerns. I’m sorry to hear about your issues with the microcell.

 

So I can further assist you, please private message me by clicking here and provide your name and serial number of the microcell.

 

We will contact you within two business days, between the hours of 11:00 am to 7:00 pm CST

 

Thanks!

Charise

 

ACE - Expert

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24.8K Messages

9 years ago

WiFi calling is coming to AT&T. There are some test markets now where WiFi calling is working just fine on iPhone 6's with iOS 9 so hang tight.

 

Work networks are difficult especially if you don't have total control yourself on firewalling etc.

 

Your VoIP tests are getting close to marginal. I would run them a couple of more times during different times of the day to get a more realistic picture line quality instead of just a snapshot in time. Speed is basically irrelevant if  you can maintain at least 3.0Mbps down and 512kbps up on a stable connection. The number of devices connected at any one time will affect that though.

 

If your home network is different that your work network, and the MicroCell works just fine at home, then that does indeed point back to your work network.

 

Port 4500 is the most common troublesome port. If AT&T says that something is blocking that port from your work internet connection then that's where you need to look. Unfortunately there is no workaround other than to have your ISP thoroughly check their network switches to make sure there is a clean path to the AT&T Mobility servers. I've seen upstream network switches configured wrong that took a very dedicated network engineer to figure out and fix.

 

The MicroCell prefers as straightforward of a connection as possible. Ideally a single ethernet cable from the MicroCell to your router with no switches, PowerLine adapters, etc in between.

 

I'm not familiar with Zscaler or OBS over NBIG but if any of that has to do with load balancing or re-prioitization then that could be a contributing factor.

 

I would try to set it up as simply as possible to remove as many devices in the pathway as is possible and then work upwards from there if there are no issues. Something has definitely changed on your network side that is preventing the MicroCell from realiably reaching the AT&T Mobility servers. Again, the MicroCell apparently works fine from you home, on I assume a different network or pathway.

 

Charise means well but if this is on your network side of things, there's nothing that AT&T can do because it's not their network.

Professor

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2.2K Messages

9 years ago

After reviewing the VOIP testing, I'd have to say that the connection quality is worse than marginal.  The jitter is bad, especially outbound.  The packet loss and discards are high and the maximum TCP delay is high.  These make me suspect that the office network has changed in some way yet to be determined that affects the Mcell.  Test results like yours are bad enough that they could be preventing the Mcell from connecting properly with AT&T servers.

 

You have proven that there is nothing wrong with your Mcell because it works at your home.  Multiple routers and switches in your office network can increase the likelihood of problems as well as network changes such as implementing a new internet security product like Zscaler.

 

I'm not sure we can help you because of the complexity of your office network.  AT&T's Customer Support certainly can not help you either as they know even less than we do about interactions between the Mcell and network hardware.

 

Good luck.

ACE - Expert

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24.8K Messages

9 years ago

Thanks for jumping in. It does sound like his work network but until the OP responds we won't know what he or they have done to remedy the situation. As you said, there's not much we or AT&T can do.

Tutor

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6 Messages

9 years ago

Hello everyone,

 

THANK-YOU for your feedback and suggestions.  We're leaving no stone unturned.  If we ever get this issue sorted out, I will certainly update this tread.  THANKS again!

 

Lar

ACE - Expert

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24.8K Messages

9 years ago

Thanks for reporting back. Hope you can get it resolved soon and yes, we'd like to know how it was resolved.

Tutor

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6 Messages

9 years ago

Just re-ran the VoIP 8x8 test again:

 

Speed test statistics
---------------------
Download speed: 15560 kbps
Upload speed: 7391 kbps
Download consistency of service: 49 %
Upload consistency of service: 68 %
Download test type: socket
Upload test type: socket
Maximum TCP delay: 87 ms
Average download pause: 2 ms
Minimum round trip time to server: 94 ms
Average round trip time to server: 96 ms
Estimated download bandwidth: 53179 kbps
Route concurrency: 3.4177017
Download TCP forced idle: 90 %
Maximum route speed: --

VoIP test statistics
--------------------
Jitter: you --> server: 0.4 ms
Jitter: server --> you: 0.2 ms
Packet loss: you --> server: 0.2 %
Packet loss: server --> you: 0.0 %
Packet discards: 0.0 %
Packets out of order: 0.0 %
Estimated MOS score: 4.0


General information
-------------------
IP address: 104.129.200.70
Local time: Sep 23, 2015 1:22:14 PM
Test server: http://voiptest.8x8.com:82/

ACE - Expert

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24.8K Messages

9 years ago

Hmm, the jitter is better but the other stats are still questionable. It appears that your line quality shifts all over the place. Stability is the key. Whenever I check my VoIP stats, there is very little variability regardless of the number of times per day I check.

 

Keep in mind that your internet service may be fine, but VoIP is a bit more picky when it comes to line quality and maintaining that secure VPN to the AT&T Mobility servers.

Tutor

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6 Messages

9 years ago

Howdy folks.

 

As best we can determine, when we moved to zscaler, the traffic takes a different route to/from the AT&T servers, making a successful response from the microcell impossible.

 

Now that AT&T has enabled WiFi calling, there is less energy to continue digging into this.

 

Oh well.

 

Thanks again for everyone's input!

ACE - Expert

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24.8K Messages

9 years ago

So far it seems that if you keep your MicroCell up and running for whatever reason, you may have to toggle Airplane Mode on to "force" your phone(s) to use WiFi for voice. If you disable the MicroCell altogether, no problem. AT&T is still rolling out WiFi so if it doesn't work correctly right away, give it a day or so. Also, the usefulness will depend, in part, on how many devices you have at any one time using your WiFi connection but so far the reports are very promising.

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