AudioCodes Mediant 800 User Manual page 485

CHAPTER 19 Coders and Profiles
Parameter
'Remote 3xx Mode'
sbc-rmt-3xx-behavior
[IpProfile_
SBCRemote3xxBehavior]
Mediant 800 Gateway & E-SBC | User's Manual
Description
■ The 'Remote Early Media RTP Behavior parameter is
set to Delayed (used in the Skype for Business
environment), and transfer target sends a 183 Session
Progress with SDP offer. If early media from the
transfer target has already been detected, the
transferee receives RTP stream from the transfer
target. If it has not been detected, the device generates
a ringback tone to the transferee and stops the tone
generation once RTP has been detected from the
transfer target.
For any of these scenarios, if the transferee is put on-hold
by the transferor, the device retrieves the transferee from
hold, sends a re-INVITE if necessary, and then plays the
ringback tone.
Note: For the device to play the ringback tone, it must be
loaded with a Prerecorded Tones (PRT) file. For more
information, see Prerecorded Tones
Defines the device's handling of SIP 3xx redirect
responses for the SIP entity associated with the IP Profile.
By default, the device's handling of SIP 3xx responses is
to send the Contact header unchanged. However, some
SIP entities may support different versions of the SIP 3xx
standard while others may not even support SIP 3xx.
When enabled, the device handles SIP redirections
between different subnets (e.g., between LAN and WAN
sides). This is required when the new address provided by
the redirector (Redirect sever) may not be reachable by the
far-end user (FEU) located in another subnet. For example,
a far-end user (FEU) in the WAN sends a SIP request via
the device to a Redirect server in the LAN, and the
Redirect server replies with a SIP 3xx response to a PBX
in the LAN in the Contact header. If the device sends this
response as is (i.e., with the original Contact header), the
FEU is unable to reach the new destination.
■ [0] Transparent = (Default) The device forwards the
received SIP 3xx response as is, without changing the
Contact header (i.e., transparent handling).
■ [1] Database URL = The device changes the Contact
header so that the re-route request is sent through the
device. The device changes the URI in the Contact
header of the received SIP 3xx response to its own URI
and adds a special user prefix ("T~&R_"), which is then
sent to the FEU. The FEU then sends a new INVITE to
the device, which the device then sends to the correct
destination.
- 445 -
File.