AudioCodes MediaPack MP-112, User Manual

Page: 490 / 622

User's Manual 490 Document #: LTRT-65417
MP-11x & MP-124
Parameter Description
parameter to 1.

If this parameter is set to Preferable [3] and two 'm=' lines are
received in the SDP offer, the device prefers the SAVP (secure
audio video profile) regardless of the order in the SDP.

Option [2] Disable is applicable only to IP Profiles.

This parameter can also be configured per IP Profile, using the
IPProfile parameter (see 'Configuring IP Profiles' on page
196 ).
Web: Master Key Identifier
(MKI) Size
EMS: Packet MKI Size
[SRTPTxPacketMKISize]
Defines the size (in bytes) of the Master Key Identifier (MKI) in SRTP
Tx packets.
The range is 0 to 4. The default value is 0 (i.e., new keys are
generated without MKI).
Notes:

For the GW/IP-to-IP application, the device only initiates the MKI
size.

You can also configure MKI size in an IP Profile.
Web:Enable symmetric MKI
negotiation
EMS: Enable Symmetric MKI
[EnableSymmetricMKI]
Enables symmetric MKI negotiation.

[0] = (Default) Disabled. The device includes the MKI in its 200 OK
response according to the SRTPTxPacketMKISize parameter (if
set to 0, then it is not included; if set to any other value, it is
included with this value).

[1] = Enabled. The answer crypto line contains (or excludes) an
MKI value according to the selected crypto line in the offer. For
example, assume that the device receives an INVITE containing
the following two crypto lines in SDP:
a=crypto:2 AES_CM_128_HMAC_SHA1_80
inline:TAaxNnQt8/qLQMnDuG4vxYfWl6K7eBK/ufk04pR4|2^
31|1:1
a=crypto:3 AES_CM_128_HMAC_SHA1_80
inline:bnuYZnMxSfUiGitviWJZmzr7OF3AiRO0l5Vnh0kH|2^
31
The first crypto line includes the MKI parameter "1:1". In the 200
OK response, the device selects one of the crypto lines (i.e., '2' or
'3'). Typically, it selects the first line that supports the crypto suite. If
the device selects crypto line '2', it includes the MKI parameter in
its answer SDP, for example:
a=crypto:2 AES_CM_128_HMAC_SHA1_80
inline:R1VyA1xV/qwBjkEklu4kSJyl3wCtYeZLq1/QFuxw|2^
31|1:1
If the device selects a crypto line that does not contain the MKI
parameter, then the MKI parameter is not included in the crypto
line in the SDP answer (even if the SRTPTxPacketMKISize
parameter is set to any value other than 0).
Notes:

To enable symmetric MKI, the SRTPTxPacketMKISize parameter
must be set to any value other than 0.

You can also enable MKI negotiation per IP Profile.
Web/EMS: SRTP offered
Suites
[SRTPofferedSuites]
Defines the offered crypto suites (cipher encryption algorithms) for
SRTP.

[0] = (Default) All available crypto suites.

[1] CIPHER SUITES AES CM 128 HMAC SHA1 80 = device uses
AES-CM encryption with a 128-bit key and HMAC-SHA1 message
authentication with a 80-bit tag.