Convert Call to DTMF VOIP
Convertion according to Table:
first digit
second digit
0
1
2
3
4
1
1
2
2
A
B
C
3
3
D
E
F
4
4
G
H
I
5
5
J
K
L
6
6
M
N
O
7
7
P
Q
R
S
8
8
T
U
V
9
9
W
X
Y
Z
0
0
Source
Everything without warranty
(c) OE2WNL
