OBi110 LINE (FXO) port connecting to HK PSTN does not pick up incoming call

因为OBi110本身的设计是按照美加的电信标准，如果我们用于香港，PSTN的ring detection不正确，所以你用电话拨打你的OBi110的LINE port的PSTN 号码，OBi110就不接！大家可以按照下面信息去更改就可以。

Modify the Ring Dection settings specifically for HK Telco Standards:

Physical Interface --> LINE port --> Ring Detection

Ring Frequency Min: 10
Ring Frequency Max: 100
Ring Validation Time: 256 ms
Ring Indication Delay: 512 ms ( same to default )
Ring Timeout: 640 ms
Ring Threshold: 13.5-16.5 Vrms
Ringer Impedance: High (Normal) ( same to default )

Reference: http://www.obitalk.com/forum/index.php?topic=396.0