A note on newer firmware on the Grandstream 1620/1625. I have two phones which are not registered on a SIP server, used for point to point contact.
Before the change, I was able to store Dial by IP address entries in the progammable keys (Line Keys/Soft Keys) by the well known method of configuring Speed Dial via Active Account (even tho there isn't one here) and an entry of *4710*1*2*3 for the IP where *47 is a prefix and the rest the IP address 10.1.2.3. Also the Settings / Call Features / Bypass Dial Plan Through Call History and Directories would need to set to Yes.
On ver 1.4.128, I noticed the speed dials had stopped working, resulting in a No matching dial plan error.
I found another instance of the Bypass Dial Plan located in Settings / Accounts / Account 1 / Call Settings. There are now check boxes specific to this Account which affect this function (again, even if account is blank). I checked "MPK" or Multi-Purpose Keys and the functionality returned.
Ian
I can't help you but I have 3 Grandstream DP715 cordless VOIP phones. You literally spelled out the best "How to save Direct IP Calling in Speed Dial" tutorial that I have yet to see on the Internet. Well done, sir. I hope someone has a solution for you. Also... I'm reluctant to upgrade my firmware after seeing your post. ;-)
Thank you,
Damon K9CQB