Nortel ISDN Signaling Link Description, Installation And Operation page 111

Figure 15
QoS levels with G.729A codec
900
800
700
600
500
400
300
200
100
Excellent
0
0
ITG Trunk 2.0 ISDN Signaling Link (ISL)
QOS levels with G.729A codec
Poor
Good
2 4 6
ITG Engineering Guidelines
Fair
8 10
Packet loss (%)
Description, Installation and Operation
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