Excerpt: Setup was easy, I am with Teliax, it took few info's about proxy and user ID and password and I was connected, my old Linksys PAP2 hit the dust after years. Just make sure before you do anything else to go to CISCO Support Web site and download newest firmware. Only minus is kind of sluggish Web UI in sense it take times to responds clicking on any hyperlink within settings page.
Summary: Two lines and not too difficult for a network savvy person to set up. You'll have router work to do and Port Forwarding setups. This converts the old analog phones to run over VOIP. This will *not* support VOIP phones and wasn't designed as such. We have two lines (one Voice line, and one Fax/junk line) and this fits the bill. You will have to find a reliable VOIP provider (we're running through VOIP.MS -- BTW five stars for these guys).
Summary: Running latest firmware 1.3.3 however 14 character caller ID names only appear as number. Issue has been posted in Cisco support forum. Requesting NCIX express RMA for full refund. Note - purchased OBi100 and caller ID works fine.
Make sure you buy a legitimate one, not a reverse engineered Chinese copy.
Amazon Customer, Amazon
10 June 2014
Summary: Get a real one. It works great. I use Vitelity.com as my VoIP provider. Do it yourself (if you are technical), don't do it if you think the internet is a series of tubes! My old one died (Spa -2102), bought this, reprovisioned it, and viola! Perfect 1.1 cents per minute and 3$ per month unlimited phone service!
Summary: I tested my analog phone by plugging it into a working pots lines and it calls out. Next I plugged the working analog phone into the Line #1 port and waited to see if the line 1 led would light but it doesn't, after waiting a long while and with the Line 1 led still not light I dial **** to enter IVR mode, if it goes into IVR mode I only hear the menu message hanging up or unplugging the phone won't stop the IVR message, only a power cycle.