Polycom DOC2702A User Manual

Page of 1010
Chapter 4-Additional Conferencing Information
Polycom, Inc.
4-41
Media Encryption for ISDN/PSTN participants is implemented in RMX systems with 
MPM+ and MPMx cards. 
Conference level encryption must be set in the Profile, and cannot be changed once the 
conference is running.
If an endpoint connected to an encrypted conference stops encrypting its media, it is 
disconnected from the conference.
In Cascaded conferences, the link between the cascaded conferences must be encrypted 
in order to encrypt the conferences.
Media Encryption for ISDN/PSTN (H.320) participants is not supported in cascaded 
conferences.
The recording link can be encrypted when recording from an encrypted conference to 
the RSS that is set to encryption. For more information, see "Recording Link Encryption” 
.
Encryption of SIP Media is supported using SRTP (Secured Real-time Transport Protocol
and the AES key exchange method.
Encryption of SIP Media requires the encryption of SIP signaling - TLS Transport Layer 
must be used.
Encryption of SIP Media is supported in CP and VSW conferences.
All media channels are encrypted: video, audio and FECC.
Encryption of SIP Media is available only in MPM+ and MPMx Card 
Configuration Modes.
RMX SRTP implementation complies with Microsoft SRTP implementation.
LPR is not supported with SRTP.
The ENABLE_SIRENLPR_SIP_ENCRYPTION System Flag enables the SirenLPR 
audio algorithm when using encryption with the SIP protocol. The default value of 
this flag is NO meaning SirenLPR is disabled by default for SIP participants in an 
encrypted conference. To enable SirenLPR the System Flag must be added to 
system.cfg and its value set to YES.
The SEND_SRTP_MKI System Flag enables or disables the inclusion of the MKI 
field in SRTP packets sent by the RMX. The default value of the flag is YES. Add 
the flag to system.cfg and set its value set to NO to disable the inclusion of the MKI 
field in SRTP packets sent by the RMX when using endpoints that cannot decrypt 
SRTP-based audio and video streams if the MKI (Master Key Identifier) field is 
included in SRTP packets sent by the RMX. This System Flag should not be set to 
NO when HDX endpoints, Microsoft Office Communicator and Lync Clients. For 
.
Mixing Encrypted and Non-encrypted Endpoints in one Conference
Mixing encrypted and non-encrypted endpoints in one conference is possible, based on the 
Encryption option “Encrypt When Possible” in the Conference Profile - Advance dialog box. 
The behavior is different for H.323/SIP and ISDN participants. 
In versions prior to version 7.6.1, this behavior is based on the setting of the system flag 
ALLOW_NON_ENCRYPT_PARTY_IN_ENCRYPT_CONF.