AudioCodes Mediant 800B MSBR User Manual page 155

User's Manual

To enable NAT resolution using the First Incoming Packet mechanism:
1. Open the General Settings page (Configuration tab > VoIP menu > Media > General
Media Settings).
2. Set the 'NAT Mode parameter to one of the following:
•
[0] Auto-Detect
•
[1] NAT Is Not Used
•
[2] NAT Is Used
3. Click Submit.
16.8.2.2.2 No-Op Packets
The device's No-Op packet support can be used to verify Real-Time Transport Protocol
(RTP) and T.38 connectivity, and to keep NAT bindings and Firewall pinholes open. The
No-Op packets are available for sending in RTP and T.38 formats.
You can control the activation of No-Op packets by using the ini file parameter
NoOpEnable. If No-Op packet transmission is activated, you can control the time interval in
which No-Op packets are sent in the case of silence (i.e., no RTP or T.38 traffic). This is
done using the ini file parameter NoOpInterval. For a description of the RTP No-Op ini file
parameters, see ''Networking Parameters'' on page 778.

RTP No-Op: The RTP No-Op support complies with IETF Internet-Draft draft-wing-
avt-rtp-noop-03 ("A No-Op Payload Format for RTP"). This IETF document defines a
No-Op payload format for RTP. The draft defines the RTP payload type as dynamic.
You can control the payload type with which the No-Op packets are sent. This is
performed using the RTPNoOpPayloadType ini parameter (see ''Networking
Parameters'' on page 778). The default payload type is 120.

T.38 No-Op: T.38 No-Op packets are sent only while a T.38 session is activated. Sent
packets are a duplication of the previously sent frame (including duplication of the
sequence number).
Note:
Version 6.8
Receipt of No-Op packets is always supported.
155
16. Network
Mediant 800B MSBR