AudioCodes Mediant 8000 - Media Security; Packet Cable Security; Secure RTP

Installation & Operation Manual 350 Document # LTRT-92224
Mediant 8000
33.13 Media Security
The Mediant 8000 Media Gateway supports two different types of Media Security:

Packet Cable Security

Secure RTP
33.13.1 Packet Cable Security
The Mediant 8000 supports media encryption via TGCP (Packet cable extension of
the MGCP protocol). IP voice traffic for some or all channels is encrypted using
predefined session keys. No key negotiation is performed for media security. Instead,
key management is handled by higher-level protocols (TGCP).
Packet Cable Security specifications:

AES (Rijndael) cipher algorithm, in CBC mode

Key strength – 128 bit

Encryption key supplied by TGCP
Packet Cable Security is enabled by default when TGCP call control is configured by
setting Call Control Compatibility Profile to 32 (in the Media Gateway Controller
configuration screen) and DSP Load File Version to 3 (in Media Gateway board
Media Settings configuration screen).
33.13.2 Secure RTP
Secure RTP, a standard protocol defined by RFC 3711, provides confidentiality,
message authentication and replay protection of the RTP & RTCP traffic. Key
negotiation is not part of the SRTP. Instead, it is handled by a higher-level protocols
(MGCP and MEGACO).
Secure RTP specifications:

Encryption – AES 128 in Counter Mode or 128 or 192 ARIA (Korean standard) for
Media Security

Authentication – HMAC-SHA1

Support of Key Derivation

Key management is provided via MGCP and MEGACO
Note: See the version-specific Release Notes to check the availability of the SRTP
application in a specific Media Gateway software release.