AudioCodes Mediant 4000 SBC, User Manual

Page: 432 / 1037

CHAPTER 19 Coders and Profiles
Mediant 4000 SBC | User's Manual
Parameter Description
■ [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.
'SBC Remove Crypto Lifetime
in SDP'
sbc-sdp-remove-crypto-
lifetime
[IpProfile_
SBCRemoveCryptoLifetimeInS
DP]
Defines the handling of the lifetime field in the 'a=crypto'
attribute of the SDP for the SIP entity associated with the
IP Profile. The SDP field defines the lifetime of the master
key as measured in maximum number of SRTP or SRTCP
packets using the master key.
■ [0] No = (Default) The device retains the lifetime field (if
present) in the SDP.
■ [1] Yes = The device removes the lifetime field from the
'a=crypto' attribute.
Note: If you configure the parameter to Yes, the following
IP Profile parameters must be configured as follows:
■ IpProfile_EnableSymmetricMKI configured to Enable
[1].
■ IpProfile_MKISize configured to 0.
■ IpProfile_SBCEnforceMKISize configured to Enforce
[1].
'SBC Remove Unknown Crypto'
sbc-remove-unknown-
crypto
[IpProfile_
SBCRemoveUnKnownCrypto]
Defines whether the device keeps or removes unknown
cryptographic suites (encryption and authentication
algorithms) that are present in the SDP 'a=crypto' attribute
in the incoming SIP message, before forwarding the
message to the SIP entity associated with this IP Profile.
■ [0] No = (Default) The device keeps all unknown
cryptographic suites that are in the SDP’s 'a=crypto'
attribute.
■ [1] Yes = The device removes all unknown
cryptographic suites that are in the SDP’s 'a=crypto'
attribute.
Note:
■ The feature is applicable only to SRTP-to-SRTP calls
and calls that do not require transcoding.
- 399 -