AudioCodes E-SBC

CHAPTER19 Coders and Profiles
Mediant 1000 Gateway & E-SBC | User's Manual
Parameter Description
■ Gateway application: The device only initiates the MKI
size.
■ SBC application: The device can forward MKI size as
is for SRTP-to-SRTP flows or override the MKI size
during negotiation. This can be done on the inbound or
outbound leg.
■ The corresponding global parameter is
SRTPTxPacketMKISize.
'SBC Enforce MKI Size'
sbc-enforce-mki-size
[IpProfile_SBCEnforceMKISize]
Enables negotiation of the Master Key Identifier (MKI)
length for SRTP-to-SRTP flows between SIP networks
(i.e., IP Groups). This includes the capability of modifying
the MKI length on the inbound or outbound SBC call leg for
the SIP entity associated with the IP Profile.
■ [0] Don't enforce = (Default) Device forwards the MKI
size as is.
■ [1] Enforce = Device changes the MKI length
according to the settings of the IP Profile parameter,
MKISize.
'Reset SRTP Upon Re-key'
reset-srtp-upon-re-key
[IpProfile_
ResetSRTPStateUponRekey]
Enables synchronization of the SRTP state between the
device and a server when a new SRTP key is generated
upon a SIP session expire. This feature ensures that the
roll-over counter (ROC), one of the parameters used in the
SRTP encryption/decryption process of the SRTP packets
is synchronized on both sides for transmit and receive
packets.
■ [0] Disable = (Default) ROC is not reset on the device
side.
■ [1] Enable = If the session expires causing a session
refresh through a re-INVITE, the device or server
generates a new key and the device resets the ROC
index (and other SRTP fields) as done by the server,
resulting in a synchronized SRTP.
Note:
■ If this feature is disabled and the server resets the ROC
upon a re-key generation, one-way voice may occur.
■ The corresponding global parameter is
ResetSRTPStateUponRekey.
'Generate SRTP Keys Mode'
generate-srtp-keys
[IpProfile_GenerateSRTPKeys]
Enables the device to generate a new SRTP key upon
receipt of a re-INVITE with the SIP entity associated with
the IP Profile.
■ [0] Only If Required = (Default) The device generates
an SRTP key only if necessary.
■ [1] Always = The device always generates a new
SRTP key.
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