Yealink VCM38 Administrator's Guide

| Configuring the Audio Settings | 159
Transmission Ways of DTMF
Three ways to transmit DTMF tones are as below: RFC2833, INBAND, SIP INFO.
RFC 2833
In-band transmission method. DTMF tones are transmitted by RTP, and the RFC 2833 packets are marked
by TeleponeEvent (RTP PayloadType). One DTMF tone consists of several RTP packets with the same
timestamps, which can be used to identify the same key. If the End bit of a RTP packet is 1, the packet is
the last DTMF tone. The default telephoneEvent is 101, but you can change it.
INBAND
In-band transmission method. DTMF tones are transmitted together with the voice band. By analyzing the
high frequency and the low frequency of the RTP packets, the device can identify the corresponding key.
SIP INFO
Out-band transmission method. DTMF tones are transmitted by SIP signaling path. The SIP INFO
message can transmit DTMF tones in three ways: DTMF, DTMF-Relay and Telephone-Event.
Setting DTMF Transmission Method for SIP Protocol
You can set the DTMF transmission method for the SIP protocol when using a SIP account, placing SIP IP
call, or logging in to Zoom, Pexip, BlueJeans, EasyMeet, or a custom third-party platform.
Procedure
1. Do one of the following:
• On your web user interface, go to Account > SIP Account/SIP IP Call.
• On your web user interface, go to Account > VC Platform > Platform Type > Zoom/Pexip/
BlueJeans/Custom.
• On your VCS devices: go to More > Settings > Advanced > Account > SIP IP Call.
On your VP59, tap > Settings > Advanced > Account > SIP IP Call.
•
On your CTP20/CTP18, tap > Settings > Advanced > Account > SIP IP Call.
2. Configure and save the following settings:
Parameter Description Configuration Method
DTMF Type
Configure the DTMF type.
• INBAND—DTMF is transmitted in the
voice band, together with the general
RTP voice packet.
• RFC2833—DTMF digits are
transmitted by RTP packet which is
compliant to RFC2833.
• SIP INFO—DTMF digits are
transmitted by SIP INFO.
• RFC2833+ SIP INFO—DTMF digits
are transmitted by RFC 2833 and the
SIP INFO.
Default: RFC2833.
Web user interface
Endpoint (remote control/VP59)
CTP20/CTP18

Yealink VCM38 Specifications

General

Type	Conference microphone
Noise reduction	Yes
Microphone frequency	100 - 16000 Hz
Microphone sensitivity	-45 dB
Microphone pick-up range	6 m
Number of microphone arrays	8
Maximum sound pressure level (1kHz)	100 dB
Device interface	RJ-45
Connectivity technology	Wired
Maximum operating distance	40 m
Mounting type	Ceiling
Product color	Silver
Operating temperature (T-T)	0 - 40 °C
Operating relative humidity (H-H)	5 - 90 %
Number of products included	1 pc(s)
Harmonized System (HS) code	85181000
Power source	DC/PoE
Sustainability certificates	CE, Federal Communications Commission (FCC), REACH, RoHS

Weight and Dimensions

Width	127.3 mm
Height	66.3 mm