Interworking Rtp-Rtcp Multiplexing; Interworking Rtcp Attribute In Sdp; Interworking Crypto Lifetime Field; Interworking Media Security Protocols - AudioCodes Mediant 4000 SBC User Manual

User's Manual
SIP entity.
For more information, see the above parameters in ''Configuring IP Profiles'' on page 418.

21.5.9.3 Interworking RTP-RTCP Multiplexing

The device supports interworking of RTP-RTCP multiplexing onto a single, local UDP port
(according to RFC 5761) between SIP entities. Employing IP Profiles, you can configure
RTP multiplexing per SIP entity, using the IPProfile_SBCRTCPMux parameter (see
''Configuring IP Profiles'' on page 418).

21.5.9.4 Interworking RTCP Attribute in SDP

The device supports interworking the RTCP attribute 'a=rtcp' in the SDP between SIP
entities. Employing IP Profiles, you can configure RTCP attribute handling (add, remove or
transparent) per SIP entity, using the IpProfile_SBCSDPHandleRTCPAttribute parameter
(see ''Configuring IP Profiles'' on page 418).

21.5.9.5 Interworking Crypto Lifetime Field

The device supports interworking the lifetime field in the 'a=crypto' attribute of the SDP,
between SIP entities. Employing IP Profiles, you can configure the lifetime field handling
(remove or retain) per SIP entity, using the IpProfile_SBCRemoveCryptoLifetimeInSDP
parameter (see ''Configuring IP Profiles'' on page 418).

21.5.9.6 Interworking Media Security Protocols

The device supports interworking media security protocols for SRTP, between SIP entities.
Employing IP Profiles, you can configure the security protocol (SDES, DTLS or both) per
SIP entity, using the IPProfile_SBCMediaSecurityMethod parameter (see ''Configuring IP
Profiles'' on page 418). For more information on SDES and DTLS, see ''Configuring Media
(SRTP) Security'' on page 204.

21.5.9.7 Interworking ICE Lite for NAT Traversal

The device supports interworking ICE for NAT traversal, between SIP entities. Employing
IP Profiles, you can enable ICE Lite per SIP entity, using the IPProfile_SBCIceMode
parameter (see ''Configuring IP Profiles'' on page 418).
21.6

Fax Negotiation and Transcoding

The device can allow fax transmissions to traverse transparently without transcoding or it
can handle the fax as follows:

Allow interoperability between different fax machines, supporting fax transcoding if
required.

Restrict usage of specific fax coders to save bandwidth, enhance performance, or
comply with supported coders. These coders include G.711 (A-Law or Mu-Law), VBD
(G.711 A-Law or G.711 Mu-Law), and T38.
Fax configuration is done in the Coder Groups table and IP Profiles table. The Coder
Groups table defines the supported coders, which is assigned to the IP Profile associated
with the SIP entity. The IP Profiles table also defines the negotiation method used between
the incoming and outgoing fax legs, using the following fax-related parameters:

IPProfile_SBCFaxBehavior: defines the offer negotiation method - pass fax
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21. SBC Overview
Mediant 4000 SBC