Last week I had to diagnose a VoIP problem for a client wherein an intercom which acted as a regular POTS “phone” was connected to their IP-based PBX. The intermediary was a small box called an Analog Telephone Adapter. The Viking model number appears to be ATA-100 while the actual Cortelco model is 8211 or 821121-ATA-PAK. The ATA registers as a generic SIP device with the PBX, but it wasn’t registering. I needed to log in to the web interface, and the client didn’t have the login.

I did a lot of googling for the model number and such, and everything I found referenced the Viking ATA-100, even though the device said Cortelco right on it. The “manual” from Viking even showed a photo of it with Cortelco all over it! I was able to find this pretty easily, and it told me that the web interface had a default IP of and lived on port 9999, so that was a start. Now I needed the credentials. The Viking manual says “the default settings are in the instructions” and to refer to the Cortelco manual which is on their web site (hint: it isn’t on their web site anymore).

I finally found a copy of the Cortelco manual buried deep in the client’s own files so I was able to find that the default user name is root with a password of test. Hooray! If you’re really desperate, you can also access some kind of phone-based menu to have the IP spoken out to you, but there are easier ways to find the IP by the MAC address printed on the device.

So, for convenience, here are the relevant settings laid out:

  • Default IP:
  • Default Port: 9999
  • Default Web Administration:
  • Username: root
  • Password: test

And here are the actual manuals:

Viking ATA-100 PDF ManualViking ATA-100 PDF Manual

Cortelco 821121-ATA-PAK PDF ManualCortelco 8211 / 821121-ATA-PAK PDF Manual

Buy the ATA100 on Amazon