CHAPTER 15 Media
Mediant 4000 SBC | User's Manual
➢
To enable support for V.34 fax relay (T.38) at SG3 speed:
1.
In the IP Profiles table (see
), configure an IP Profile with the 'Fax
Signaling Method' parameter (IpProfile_IsFaxUsed) set to
T.38 Relay
.
2.
In the Coder Groups table (see
) set the coder used by the device to
G.729 (or any other supported codec).
3.
On the Fax/Modem/CID Settings page, do the following settings:
●
'SIP T.38 Version' to
Version 3
(SIPT38Version = 3).
●
'Fax Relay Max Rate' (RelayMaxRate) to
33,600bps
(default).
●
'CNG Detector Mode' (CNGDetectorMode) to
Disable
(default).
●
'V.21 Modem Transport Type' to
Disable
(V21ModemTransportType = 0).
●
'V.22 Modem Transport Type' to
Disable
(V22ModemTransportType = 0).
●
'V.23 Modem Transport Type' to
Disable
(V23ModemTransportType = 0).
●
'V.32 Modem Transport Type' to
Disable
(V32ModemTransportType = 0).
●
'V.34 Modem Transport Type' to
Disable
(V34ModemTransportType = 0).
●
'CED Transfer Mode' to Fax Relay or VBD (CEDTransferMode = 0).
4.
Set the ini file parameter, V34FaxTransportType to 1 (i.e., relay).
5.
Set the ini file parameter, T38MaxDatagramSize to 560 (default).
●
The T.38 negotiation should be completed at call start according to V.152
procedure (as shown in the INVITE example below).
●
T.38 mid-call Re-INVITEs are supported.
●
If the remote party supports only T.38 Version 0, the device "downgrades" the T.38
Version 3 to T.38 Version 0.
For example, the device sends or receives the following INVITE message, negotiating both audio
and image media:
INVITE sip:[email protected];user=phone SIP/2.0
Via: SIP/2.0/UDP 10.8.6.55;branch=z9hG4bKac1938966220
Max-Forwards: 70
From: <sip:[email protected]>;tag=1c1938956155
To: <sip:[email protected];user=phone>
Call-ID: [email protected]
CSeq: 1 INVITE
Contact: <sip:[email protected]:5060>
Supported: em,100rel,timer,replaces,path,resource-priority,sdp-anat
Allow:
REGISTER,OPTIONS,INVITE,ACK,CANCEL,BYE,NOTIFY,PRACK,REFER,INFO,SU
BSCRIBE,UPDATE
Remote-Party-ID: <sip:[email protected]>;party=calling;privacy=off;screen=no;screen-
ind=0;npi=1;ton=0
Remote-Party-ID: <sip:[email protected]>;party=called;npi=1;ton=0
User-Agent: AudioCodes-Sip-Gateway-/7.20A.252.011
Content-Type: application/sdp
Content-Length: 433
v=0
o=AudioCodesGW 1938931006 1938930708 IN IP4 10.8.6.55
s=Phone-Call
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Summary of Contents for Mediant 4000 SBC
Page 1: ...User s Manual AudioCodes Series of Session Border Controllers SBC Mediant 4000 SBC Version 7 2...
Page 40: ...Part I Getting Started with Initial Connectivity...
Page 48: ...Part II Management Tools...
Page 113: ...Part III General System Settings...
Page 118: ...Part IV General VoIP Configuration...
Page 525: ...Part V Session Border Controller Application...
Page 654: ...Part VI Cloud Resilience Package...
Page 663: ...Part VII High Availability System...
Page 685: ...Part VIII Maintenance...
Page 759: ...Part IX Status Performance Monitoring and Reporting...
Page 844: ...Part X Diagnostics...
Page 888: ...Part XI Appendix...