Ring Tones

[Charliestott]

Hi
I have an issue with a pbx and distinctive ring tones.
what i need is the following .
Phones are t20's t26. t38. t42, t46's w52's (28 total)

so
external call tone 1
internal call tone 2

external call transfer tone 2 ? (shows as internal call should be tone 1)

external call on hold and transfer should be tone 2 !!

Hope this can be answered and is possible.

i have a Zycoo u20 and a grandstream umc 61xx

Thanks in advance for your help ....