Gotchas to Watch for When Migrating from pbxnsip to snom ONE
-Blue will allow up to 40 non-snom devices to register. (snom ONE looks at the user-agent string in SIP and if it doesn't contain "snom" it will limit it to 5 in snom ONE Free, 10 in Yellow and 40 in Blue respectively)
-Note that I used the word "allow" instead of "supported". This was intentional as you will need to do the interop testing yourself. Which usually is not a big hurdle for basic functionality.
-Remember that these allowed non snom devices will have a limitation that they will not support a SIP REFER. In the real world this means that, for one, the Transfer button on software and hard phone will likely not work. This is not the end of the world though as with snom ONE you can put the call on hold and use the built in star code to transfer as a work around.
-Also note that snom ONE Blue only allow 5 domains (tenants) is not meant (licensing/eula) for reselling hosted service to other customers. I'm not sure how this is enforced and I suppose it can get grey? if a company owns a building and rents to tenants.
-snom ONE blue does not automatically auto-provision brands other than snom handsets.