18.3.4.2. SPE for IP Subscribers 
IMPORTANT:
For SIP stations to continue to work once SPE
is activated (via AMO ZANDE and/or AMO SIPCO) a Hard Restart must be
performed. On a duplex system two hard restarts are required after each
other to ensure all gateways are loaded new with the new SPE configuration.
IMPORTANT:
For SIP subscribers only SDES as payload encryption
mode is supported, Because SDES is not supported on STMI boards, no payload
encryption is possible.
A list of the subscribers which support SPE is available in the ReleaseNote/
compatibility matrix.