In this section:
The SBC Core supports ICE and DTLS with direct media and antitrombone scenarios. Any call, which is setup as Direct Media call can become a non-Direct Media call due to call transfer or Re-INVITE. The SBC supports conversion of a Direct Media call to Non Direct media and vice versa and handles the ICE/DTLS interactions as per the following:
ice-ufrag
ice-pwd
ice-lite
ice-mismatch
candidate
remote-candidates
ice-options
end-of-candidates
setup (active/passive)
fingerprint
ICE-Lite procedure for a call when it is reconfigured as non-direct media after setting up as a direct media call initially.
Reconfiguring a call to direct media with end to end ICE procedures after it is setup as non-direct media call using ICE-Lite procedures.
Transferring a non-direct media call that used ICE-Lite to a direct media call to another party by Refer mechanism.
The SBC does not play any role in the ICE procedures for the transfer of a direct media call (that is connected through an AS) to a direct media call to another party except relaying the SDP parameters.
In inter-SBC direct media scenario, the call legs are on different SBCs.
The following diagram illustrates inter-SBC direct media scenario with end to end ICE and DTLS procedure.
In intra-SBC direct media scenario, both the call legs are on same SBC.
The following diagram illustrates intra-SBC direct media scenario with end to end ICE and DTLS procedure.
If both DTLS relay and Direct Media are configured on SBC, Direct Media takes precedence over DTLS relay.
Antitrombone direct media uses normal direct media on the SBC facing the endpoints and antitrombone configuration on the SBC side facing the SIP AS. This feature is useful when x-dmi cannot be passed through the SIP AS. For more information, refer to Media Antitrombone.
When a call is established as an ICE direct media call, the SBC does not support media handling. Therefore, the existing CDR fields are populated for Ingress and Egress local Ip address/ports as 255.255.255.255/65535 and Ingress and Egress remote IP address/ports as 127.0.0.0/5004 for each of the media streams on the call. For more information, refer to the section CDR Field Descriptions.
The MS Lync/Skype Remote Desktop Sharing feature is supported on all SBC Core platforms: