Modem Relay - AudioCodes Mediant 3000 User Manual

12.2.4 V.150.1 Modem Relay
The device can be configured to transfer modem calls using a subset of the ITU-T V.150.1
Modem Relay protocol. The device also supports V.150.1 modem relay coder negotiation
in the initial SIP INVITE and 200 OK, using the SDP body (according to the UCR-2008,
Change 2 specification). This eliminates the need for sending a re-INVITE to negotiate
V.150.1.
Notes:

To configure V.150.1 Modem relay:
1. In the Coders table, select the v1501mr coder.
2. Open the Fax/Modem/CID Settings page (Configuration tab > VoIP menu > Media
submenu > Fax/Modem/CID Settings), and configure the V.150.1 parameters:
•
The Allocation Profile is an offline parameter which controls how many of the
DSPs on the blade are allocated for regular voice and how many are allocated for
V.150.1 Modem Relay capability. The table below describes the presently
supported options of the Allocation Profile. The default value of the parameter is
"0", in which no modem channel is being allocated.
Blade
TP-8410 16 E1/21 T1
TP-8410 16 E1/21 T1
TP-8410
TP-6310
Notes:
As soon as the V.150.1 session has been negotiated and activated by SIP, a Modem
Relay DSP channel is allocated alongside the existing allocated Voice DSP channel.
The DSP Modem Relay channel is responsible for the whole V.150.1 part of the call.
•
SSE Payload Type Rx: the V.150.1 SSE payload type that the device uses when
it offers the SDP. The default value is 105.
•
SSE Redundancy Depth determines how many SSE redundant packets are sent.
This parameter is important in case of network impairments. Its default value is
set to 3.
SIP User's Manual
•
The V.150.1 Modem Relay feature support is a subset of the full V.150.1
protocol and is designed according to the US DOD requirement
document. It therefore cannot be used for general purposes.
•
The V.150.1 Modem Relay feature is available only if the device is
installed with the V.150.1 Software Upgrade Key.
•
The V.150.1 feature has been tested with certain IP phones. For more
details, please contact your AudioCodes sales representative.
Table 12-1: Allocation Profile Options
Allocation Profile
Value
2
4
11
11
•
The TP-8410 16 E1/21 T1 blade contains 6 DSPs supporting up to 21
DS1 spans. The TP-8410 and TP-6310 blades contain 21 DSPs,
supporting up to 84 DS1 spans.
•
The Number Of Voice Channels column represents channel density
when the blade supports SRTP.
Number of Voice
Channels
336
168
840
840
166
Mediant 3000
Number of Modem
Channels
48
96
264
264
Document #: LTRT-89712