By default, if you go off hook on a SPA phone and do not dial anything, the phone will start playing fast-busy.
Usually this behavior is desirable, but what if you're configuring a phone for an older user who may go off hook and then start looking for the phone number to dial?
You may decide to resolve the issue by increasing the length of the dial plan P timer from the default of 5 to 19 seconds as follows:
Default dial plan:
<Dial_Plan_1_ ua="na">(*xx|[3469]11|0|00|[2-9]xxxxxx|1xxx[2-9]xxxxxxS0|xxxxxxxxxxxx.)</Dial_Plan_1_>
Modified dial plan with P-timer set to 19:
<Dial_Plan_1_ ua="na">(P19|*xx|[3469]11|0|00|[2-9]xxxxxx|1xxx[2-9]xxxxxxS0|xxxxxxxxxxxx.)</Dial_Plan_1_>
When you start testing, you'll notice that after 10 seconds, the phone starts playing fast busy. This is most certainly not what you expected.
This is because the dial tone script defines dial tone to play for 10 seconds by default.
Change it to 19 seconds as follows:
Default dial tone:
<Dial_Tone ua="na">350@-19,440@-19;10(*/0/1+2)</Dial_Tone>
Modified dial tone to play for up to 19 seconds:
<Dial_Tone ua="na"> 350@-19,440@-19;19(*/0/1+2)</Dial_Tone>
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