AudioCodes Mediant 4000 SBC, Руководство пользователя

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CHAPTER 19 Coders and Profiles
Mediant 4000 SBC | User's Manual
Parameter Description
■ [2] Preferred Value = Use the ptime according to the
'Preferred Ptime' parameter (see below) if it is
configured to a non-zero value.
Note:
■ Regardless of the settings of this parameter, if a non-
zero value is configured for the 'Preferred Ptime'
parameter (see below), it is used as the ptime in the
SDP offer.
'Preferred Ptime'
sbc-preferred-ptime
[IpProfile_SBCPreferredPTime]
Defines the packetization time (ptime) in msec for the SIP
entity associated with the IP Profile, in the outgoing SDP
offer.
If the 'SDP Ptime Answer' parameter (see above) is
configured to Preferred Value [2] and the 'Preferred Ptime'
parameter is configured to a non-zero value, the configured
ptime is used (enabling ptime transrating if the other side
uses a different ptime).
If the 'SDP Ptime Answer' parameter is configured to
Remote Answer [0] or Original Offer [1] and the 'Preferred
Ptime' parameter is configured to a non-zero value, the
configured value is used as the ptime in the SDP offer.
The valid range is 0 to 200. The default is 0 (i.e., a preferred
ptime is not used).
'Use Silence Suppression'
sbc-use-silence-supp
[IpProfile_
SBCUseSilenceSupp]
Defines silence suppression support for the SIP entity
associated with the IP Profile
■ [0] Transparent = (Default) Forward as is.
■ [1] Add = Enable silence suppression for each relevant
coder listed in the SDP.
■ [2] Remove = Disable silence suppression for each
relevant coder listed in the SDP.
Note: The parameter requires DSP resources.
'RTP Redundancy Mode'
sbc-rtp-red-behav
[IpProfile_
SBCRTPRedundancyBehavior]
Enables interworking RTP redundancy negotiation support
between SIP entities in the SDP offer-answer exchange
(according to RFC 2198). The parameter defines the
device's handling of RTP redundancy for the SIP entity
associated with the IP Profile. According to the RTP
redundancy SDP offer/answer negotiation, the device uses
or discards the RTP redundancy packets. The parameter
enables asymmetric RTP redundancy, whereby the device
can transmit and receive RTP redundancy packets to and
from a specific SIP entity, while transmitting and receiving
regular RTP packets (no redundancy) for the other SIP
entity involved in the voice path.
The device can identify the RTP redundancy payload type
in the SDP for indicating that the RTP packet stream
includes redundant packets. RTP redundancy is indicated
in SDP using the "red" coder type, for example:
a=rtpmap:<payload type> red/8000/1
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