AudioCodes Mediant 4000 SBC, User Manual

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CHAPTER 60 Configuration Parameters Reference
Mediant 4000 SBC | User's Manual
Parameter Description
■ [1] Dynamic = (Default) Device latches on to the first
stream. If it receives at least a minimum number of
consecutive packets (configured by New<media
type>StreamPackets) from a different source(s) and
the device has not received packets from the current
stream for a user-defined period
(TimeoutToRelatch<media type>Msec), it latches on
to the next packet received from any other stream. If
other packets of a different media type are received
from the new stream, based on IP address and SSRC
for RTCP/RTP and based on IP address only for T.38,
the packet is accepted immediately.
Note: If a packet from the original (first latched onto)
IP address:port is received at any time, the device
latches on to this stream.
■ [2] Dynamic-Strict = Device latches on to the first
stream. If it receives at least a minimum number of
consecutive packets (configured by New<media
type>StreamPackets) all from the same source which
is different to the first stream and the device has not
received packets from the current stream for a user-
defined period (TimeoutToRelatch<media
type>Msec), it latches on to the next packet received
from any other stream. If other packets of different
media type are received from the new stream based
on IP address and SSRC for RTCP and based on IP
address only for T.38, the packet is accepted
immediately.
Note: If a packet from the original (first latched onto)
IP address:port is received at any time, the device
latches on to this stream.
■ [3] Strict-On-First = Typically used for NAT, where
the correct IP address:port is initially unknown. The
device latches on to the stream received in the first
packet. The device does not change this stream
unless a packet is later received from the original
source.
Note: If you configure the parameter to [0] Strict, the
device cannot perform NAT traversal. In this setup,
configure the NATMode parameter to [1] Disable NAT.
'New RTP Stream Packets'
[NewRtpStreamPackets]
Defines the minimum number of continuous RTP packets
received by the device's channel to allow latching onto the
new incoming stream.
The valid range is 0 to 20. The default is 3. If set to 0, the
device is left exposed to attacks against multiple packet
streams.
'New RTCP Stream Packets'
[NewRtcpStreamPackets]
Defines the minimum number of continuous RTCP
packets received by the device's channel to allow latching
onto the new incoming stream.
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