keywords: FreeSWITCH 忙音檢測 呼叫進度檢測 信號音檢測 detect busy ringing
description: FreeSWITCH忙音信號檢測使用方法
categories: FreeSWITCH
FreeSWTICH有2種信號音檢測方法一種mod_dptools: tone_detect，還有一個是mod_spandsp Call Progress,我們先介紹第一種。
mod_dptools tone_detect
<action application="tone_detect" data="<key> <freqs> <flags> <timeout> <app> <data> <hits>">| Field | Decription | examples |
|---|---|---|
| key | Name of the tone (user defined) | busy, fax, mytone |
| freqs | Frequencies to “listen” for | 425 - 480,620 |
| flags | Which direction to sniff the tones in (r = read (default), w = write) | r |
| timeout | Window of time to listen for the tones in (0 = forever, + = milliseconds relative to the time tone_detect is called (now), = time in “epoch” (ie. seconds since January 1, 1970)) | +2000 (2 seconds) or 1227132612 (absolute example) |
| app | Optional. Application to call when the tone detect conditions are met | transfer, hangup |
| appdata | Optional. Argument to the application specified above | ‘1000 XML default’ , ‘normal_clearing’ |
| hits | Number of hits needed before calling app/appdata (useful to avoid false positives) |
timeout這裏特別解析一下，0：一直檢測，+毫秒數：需要檢測的時間, epoch：絕對時間，比如要檢測60秒，就是now()+60
freqs 中國電話信號音標準
- 撥號音 450±25 －10±3dBm0 <10% 連續信號音
- 回鈴音 450±25 －10±3dBm0 <10% 1S(H)/4S(L)
- 忙音 450±25 －10±3dBm0 <10% 0.35S(H)/0.35S(L)
- 擁塞音 450±25 －10±3dBm0 <10% 0.7S(H)/0.7S(L)
如果上面表格中解析看不明白，沒事，下面有例子。
<!-- execute_on_tone_detect 檢測到信號音執行的操作 -->
<action application="set" data="execute_on_tone_detect=set my_tone=true"/>
<!-- tone_detect_hits 信號出現多少次才認爲檢測成功，比如忙音檢測一般設置爲3 -->
<action application="set" data="tone_detect_hits=2"/>
<action application="set" data="execute_on_media=tone_detect mytone 820 w +30000"/>
<action application="bridge" data="sofia/gateway/foo/123456789"/>下面是一個檢測到3聲忙音就掛斷的例子。
<action application="tone_detect" data="busy 450 r 0 hangup 'normal_clearing' 3"/>停止信號音檢測
<application="stop_tone_detect"/>mod_spandsp Call Progress
mod_dptools: tone_detect功能比較弱，現在我們介紹第二種吧
<configuration name="spandsp.conf" description="Tone detector descriptors">
<descriptors debug-level="0">
<!-- These tones are defined in Annex to ITU Operational Bulletin No. 781 - 1.II.2003 -->
<!-- Various Tones Used in National Networks (According to ITU-T Recommendation E.180)(03/1998) -->
<!-- North America -->
<!-- china -->
<descriptor name="cn">
<tone name="BUSY_TONE">
<element freq1="450" freq2="0" min="300" max="400"/>
<element freq1="0" freq2="0" min="300" max="400"/>
<element freq1="450" freq2="0" min="300" max="400"/>
<element freq1="0" freq2="0" min="300" max="400"/>
<element freq1="450" freq2="0" min="300" max="400"/>
<element freq1="0" freq2="0" min="300" max="400"/>
</tone>
</descriptor>
</descriptors>
</configuration>通過配置文件可以配置不同信號因頻率、持續時間和週期。上面的配置是配置中國忙音，持續3聲認爲檢測成功。
Channels Variables
- execute_on_spandsp_tone_detect_XXX 檢測到信號執行APP
- api_on_spandsp_tone_detect_XXX 檢測到信號執行API
Dialplan Applications
spandsp_start_tone_detect
Start background tone detection with cadence.
<!-- start detection for North American call progress tones -->
<action application="spandsp_start_tone_detect" data="1"/>
spandsp_stop_tone_detect
Stop background tone detection with cadence
<action application="spandsp_stop_tone_detect"/>APIs
spandsp_start_tone_detect
Start background tone detection with cadence
spandsp_start_tone_detect <uuid> <descriptor name>spandsp_stop_tone_detect
Stop background tone detection with cadence
spandsp_stop_tone_detect <uuid>Events
DETECTED_TONE
This event is fired when the tone detector detects a tone.
The following headers are set:
Detected-Tone
Unique-ID
The Detected-Tone header will contain the name of the tone, as specified in the configuration file.
The Unique-ID will contain the session UUID.