AudioCodes MediaPack MP-201B, User Manual, Page: 49 / 270

Version 3.0.1 49 July 2010
MP-20x Telephone Adapter 5. Configuring VoIP Parameters
Table 5-3: Media Streaming Tab Parameters Description
Parameter Description
Codecs
1st Codec Refer to 'Configuring Codecs' on page 49
2nd Codec Refer to 'Configuring Codecs' on page 49
3rd Codec Refer to 'Configuring Codecs' on page 49
4th Codec Refer to 'Configuring Codecs' on page 49
5th Codec Refer to 'Configuring Codecs' on page 49
6th Codec Refer to 'Configuring Codecs' on page 49
Media Streaming Parameters
Local RTP Port Range -
Contiguous Series of 8
Ports Starting From: Defines the port range for Real Time Protocol (RTP) voice transport.
DTMF Relay RFC 2833
Payload Type The RTP payload type used for RFC 2833 DTMF relay packets. Range = 0-
255. Default = 101.
G.726/16 Payload Type The RTP payload type used for 16 kbps G.726 packets. Range = 0-255.
Default = 98.
Quality of Service Parameters
Type of Service (Hex) This is a part of the IP header that defines the type of routing service to be
used to tag outgoing voice packets, originated from MP-20x. It is used to
tell routers along the way that this packet should get specific QoS. Leave
this value as 0xb8 (default) if you are unfamiliar with the Differentiated
Services IP protocol parameter.
G.723 Bitrate
G.723 Bitrate Toggles between low and high bit rate for G.723.
5.3.1 Configuring Codecs
Codecs define the method of relaying voice data. Different codecs have different
characteristics, such as data compression and voice quality. For example, G.723 is a
codec that uses compression, so it is good for use where bandwidth is limited but its voice
quality is not as good compared to other codecs such as the G.711.
5.3.1.1 Supported Codecs
To make a call, at least one codec must be enabled. Moreover, all codecs may be enabled
for best performance. When you start a call to a remote party, your available codecs are
compared against the remote party's to determine which codec is to be used. The priority
by which the codecs are compared is according to the descending order of their list. To
change the priorities, rearrange the codecs in the required order.
If there is no codec that both parties have made available, the call attempt fails. Note that if
more than one codec is common to both parties, you cannot force which of the common
codecs that were found are used by the remote party's client. If you do wish to force the
use of a specific codec, leave only that codec checked.