Polycom CX5500 Administrator's Manual page 187

Polycom CX5500 Unified Conference Station Administrator's Guide
1.1.0
In the following example, the srtp_1.cfg configuration file is shown below:
This would result in an offer (SIP INVITE with SDP) with 8 crypto attributes with the following session
parameters:
<no session parameters> UNENCRYPTED_SRTCP UNENCRYPTED_SRTP
UNAUTHENTICATED_SRTP
UNAUTHENTICATED_SRTP,UNENCRYPTED_SRTCP UNENCRYPTED_SRTP,UNENCRYPTED_SRTCP
UNAUTHENTICATED_SRTP,UNENCRYPTED_SRTP
UNAUTHENTICATED_SRTP,UNENCRYPTED_SRTP,UNENCRYPTED_SRTCP
In the above example, the crypto attributes are ordered "most secure" to "least secure" (more security
turned off). The phone receiving this call should chose the most secure crypto it can support based on the
SRTP require settings in sip.cfg and reply with it in the SDP of a 200 OK SIP message.
In this example, the srtp_2.cfg configuration file is shown below:
This results in an offer (SIP INVITE with SDP) with 4 crypto attributes with the following session
parameters:
UNENCRYPTED_SRTP UNENCRYPTED_SRTP,UNENCRYPTED_SRTCP
UNAUTHENTICATED_SRTP,UNENCRYPTED_SRTP
UNAUTHENTICATED_SRTP,UNENCRYPTED_SRTP,UNENCRYPTED_SRTCP
In the above example, every crypto includes the UNENCRYPTED_SRTP session parameter because it is
required.
If nothing compatible is offered based on the receiving phone's STRP "require" settings, then the call is
rejected or dropped.
Polycom, Inc. 187