Yealink SIP-T4X Administrator's Manual page 146

Administrator's Guide for SIP-T4X IP Phones
Distinctive ring tones allows particular incoming calls to trigger IP phones to play
distinctive ring tones. The IP phone inspects the INVITE request for an "Alert-Info" header
when receiving an incoming call. If the INVITE request contains an "Alert-Info" header,
the IP phone strips out the URL and keyword parameter and maps it to the appropriate
ring tone.
Alert-Info headers in the following four formats:
Alert-Info: localIP/Bellcore-drN
Alert-Info: ringtone-N (or Alert-Info: MyMelodyN)
Alert-Info: <URL>
Alert-Info: info=info text;x-line-id=0
If the Alter-Info header contains the keyword ―Bellcore-drN‖, and the parameter

―features.alert_info_tone‖ is set to 1, the IP phone will play the Bellcore-drN ring
tone (N=1, 2, 3, 4 or 5). Otherwise, the IP phone will play the preconfigured local
ring tone in about ten seconds.
Example:
Alert-Info: http://127.0.0.1/Bellcore-dr1
The following table identifies the different Bellcore ring tone patterns and
cadences (These ring tones are designed for the BroadWorks server).
Bellcore
Tone
Bellcore-dr1
(standard)
Bellcore-dr2
Bellcore-dr3
Bellcore-dr4
130
Pattern
Pattern Cadence
ID
Ringing 2s On
1
Silent 4s Off
Ringing Long
Silent
2
Ringing Long
Silent
Ringing Short
Silent
Ringing Short
3
Silent
Ringing Long
Silent
4 Ringing Short
Minimum Nominal
Duration Duration
(ms) (ms)
1800 2000
3600 4000
630 800
315 400
630 800
3475 4000
315 400
145 200
315 400
145 200
630 800
2975 4000
200 300
Maximum
Duration
(ms)
2200
4400
1025
525
1025
4400
525
525
525
525
1025
4400
525