Specifications

Chapter 11 - Fax Transmission T.38 Fax
150
Mediatrix 4100
The Mediatrix 4100 can send faxes in T.38 mode over UDP. T.38 is used for fax if both units are T.38 capable;
otherwise, transmission in clear channel over G.711 as defined is used (if G.711 µ-law and/or G.711 A-law are
enabled). If no clear channel codecs are enabled and the other endpoint is not T.38 capable, the fax
transmission fails.
The following is a T.38 fax call flow:
Figure 31: T.38 Fax Call Flow
In the Unit Manager Network Administration Manual, refer to chapter Ports Parameters, section Port
Configuration Window.
C
R
C
X
2
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0
O
K
[…]
m=audio 5004 RTP/AVP 18
C
R
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R: G/ft
[… ]
m=audio 5004 RTP/AVP 18
2
0
0
O
K
[…]
m=audio 5006 RTP /AVP 18
M
D
C
X
[…]
m=audio 5006 RTP/AVP 18
2
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0
O
K
RTP=G.729 (Voice Call )
T.38
Fax is terminated
U
s
e
r
A
g
e
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t
#
2
D
e
t
e
c
t
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F
a
x
T
o
n
e
User Agent
#1
Call Agent
User Agent
#2
……...
…………..
……………….
……...
…………..
……………….
[…]
R: G/ft
[…]
N
T
F
Y
O
:
G
/
f
t
M
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2
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M
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[…]
LCO image/t38
[…]
2
0
0
O
K
[…]
m=image 6006 udptl t38
[…]
[…]
m=image 6006 udptl t38
[…]
2
0
0
O
K
[…]
m=image 6004 udptl t38
[…]
M
D
C
X
[…]
m=image 6004 udptl t38
[…]
2
0
0
O
K