Writing this down before I forget it all....
I spent a few hours this weekend setting up a Cisco SPA525G IP phone to get it on the air with the public switched phone network and with two ham radio PBX networks: Hams over IP and Hamshack Hotline.
The first part of the setup really didn't take very long, but it's what had stymied me in the first place: getting the Cisco phone onto our wifi. Turns out you need to match the encryption type of the phone with the encryption type of the router; in my case that meant selecting WPA2 PSK AES. It's all spelled out on page 30 of the Cisco docs - the Cisco 525G user guide - but of course I wasn't looking at the docs as I was fumbling through the various options trying to just make it work.
Once the phone was on the air, the next thing to do was to get it connected to the various VOIP networks I have access to. The helpful thing about this phone is that it has a web server built in, so it's not necessary once you get it online to punch buttons the phone to get all of the details.
I started with Voip.MS which is a subscription based VOIP network that connects you phone to the public switched telephone network. The Voip.MS wiki page for the SPA525G has the necessary information for connecting a line. I had previously set up a line with my cell phone and my MacBook Air using Zoiper, so the configuration involved adding an additional extension to point to the Cisco phone.
The "Phone" tab on the Cisco's web server lets you map lines to extensions. When I had first set things up, all 5 of the extensions pointed to the first line. Map "Line key" to "extension" as appropriate, or keep some lines disabled.
The second system to set up was Hams over IP. This is a "bring your own device" VOIP network for hams. Again there is a wiki page for the Cisco 525g which answers all of the necessary questions for configuration.
Finally I requested and got a link to Ham Shack Hotline or HH. This was a little bit more complicated than the first two. Ham Shack Hotline has a very helpful standard configuration for these devices that fully provisions them according to their specifications, but in the process it wipes out all of the other configs on your phone. If you want to support multiple networks at the same time, you need to get an "experimental" line on their HHUX server. Fortunately, the actual configuration I had been through twice successfully on other providers so even though I was "on my own" to configure things I basically followed the previous setup pattern and all was well.
What can you do with this VOIP configuration?
With the VOIP.ms line I can make regular phone calls. I called and talked to my Mom, the sound quality was fine, the caller ID came through with my name so she knew it was me. I'm looking forward to porting over our home phone line to this system so I can dial out directly with a well-known number.
With Hams over IP and Ham Shack Hotline, I can patch into what is a bewildering variety of linked digital networks. Most of these connections go in some way to linked Allstar nodes, and the corresponding sound quality is quite good.
As an example, I had a QSO with Lucille KD8PTE through Ham Shack Hotline on the K8LOD 147.27+ repeater in Marquette. She was connecting via RF to the repeater, and there's a Ham Shack Hotline interface to the Allstar node, using HH extension 94026. Sound quality was good with none of the "robotic" sorts of sharp edges that you can sometimes hear on DMR connections.
The other connection I made tonight was to Christopher M0YNG who dialed me direct on Hams over IP. The connection was from his PBX in the UK to a softphone running on my MacBook Air (Zoiper) and the sound quality was excellent. (But was it amateur radio? Neither of us were using the ham bands so there was no need to limit our conversation to ham topics.)
All things considered quite some progress! My next step is to take all of this hard-won experience and venture into porting a phone number to my phone, moving the land line number to a new provider. How hard could it be? (And this is definitely not amateur radio.)