atcomsystems.ca/forum Forums Wiring - Telecom Carriers - Trunks & Services Telecom Service & Providers Looking for advice on troubleshooting

Hi,

I have an issue which I have been working on for a few months now with our datacenter tech/phone guy. I have detailed it below and am looking for some advice/help. Please forgive my phone system ignorance.

I had two servers in a data center each with four modems attached. I used these to dial around 750 different client modems around the world. This worked great for the last three years without any issues. Recently we moved to a new datacenter in a different part of the country. I requested that we have POTS lines installed for the modems. This was done. (They claim they are POTS lines). When I dial out to about 40% of the devices in the field I can no longer connect to them. I just get a no carrier message. To rule out my hardware I had one of the modems shipped to me in my local office and tested dialing the clients successfully. I requested the datacenter tech have AT&T come check the lines. They came out three times and told us everything was ok. The fourth time they told us they found some crossed lines at the demark point and fixed it.

After this I still was stuck wit the same problem. I can't connect using the modems to the client devices unless I set the rate as low as 300 baud and at that point it doesn't seem to make a really successful connection.

The data center tech tells me he checked all the patches that he ran. He setup a laptop on one line and called another and transferred a file successfully saying that he went to the CO and back and there are no issues at all.

I don't know what else to ask them to check. They have no butt sett ( or wont budget to buy one) either. I really think that there is still a problem somewhere because from any other POTS line i have used I can connect to the modems at a decent rate. When using our datacenter lines I cannot.

If anyone has some idea of what I could ask to have checked or point me to a site detailing phone systems and such I would greatly appreciate it. I would also trade my time as a network engineer to help you with some project.

In addition after finally connecting to a client modem after ten or so tries I printed this diagnostics message.

AT S7=75 S0=0 L1 V1 X4 &c1 E1 S30=10 Q0                                                   
OK                                                                                         
ati11                                                                                     
                                                                                          
    Description                         Status
    ---------------                     ------------
    Last Connection                     V.32           
    Initial Transmit Carrier Rate       1200           
    Initial Receive  Carrier Rate       1200           
    Final   Transmit Carrier Rate       1200            
    Final   Receive  Carrier Rate       1200           
    Protocol Negotiation Result         LAPM/SREJ      
    Data Compression Result             NONE           
    Estimated Noise Level               655            
    Receive  Signal Power Level  (-dBm) 4              
    Transmit Signal Power Level  (-dBm) 11             
    Round Trip Delay             (msec) 0              
Press any key to continue; ESC to quit.
 
    Description                         Status
    ---------------                     ------------
    Near Echo Level              (-dBm) 0              
    Far  Echo Level              (-dBm) 0              
    Transmit Frame Count                32             
    Transmit Frame Error Count          0              
    Receive  Frame Count                29             
    Receive  Frame Error Count          0              
    Retrain by Local  Modem             0              
    Retrain by Remote Modem             0              
    Rate Renegotiation by Local Modem   0              
    Rate Renegotiation by Remote Modem  0              
    Call Termination Cause              0              
    Robbed-Bit Signaling                NA             
    Digital Loss                   (dB) NA             
    Remote Server ID                    NA             
    Last PCM S PTR                      00             
 
OK


Thanks.

Where is your new center? You say they are using POTS. As in copper back to the CO, or U verse? I'm betting you're either on a local carrier or U verse.

If they don't have a butt set they aren't phone guys ...get a real phone technician on site to check things out.

Find out if ATT is providing the "POTS" lines via a dynamic T-1 (on a VoIP backbone) and channel bank. Modems don't like that.

Thanks for the tips. I appreciate it!

I suspect you don't have a real POTS line too. ATT is not a local carrier (ILEC). Contact the local carrier for your data center location and have them put in a real POTS line.

Why not send the computers back to the old data center?

Why not host the computers in your own ofice or home so you can access them?

That used to be true until SBC bought out AT&T and became at&t and also bought up other ILEC's.

This sounds more complicated than the Byzantine empire. So which local phone companies (ILECS) are now owned by ATT?

So as not to hijack this thread I'll start a new topic on that.

For a quick example, ATT directly provides many services from POTS, T1's, up to 10G opt-e-man circuits (and probably more) in my area. As of late they often deliver multiple untagged circuits aswell