Nortel 1110 Installation And Operation Manual page 499

• IP Phone 1140E
• IP Phone 1150E
For information about configuring the SRTP media encryption feature, see
the applicable IP Phone section.
Note 1: During a firmware upgrade, the SRTP media encryption feature
will be automatically disabled.
Note 2: The SRTP media encryption feature does not support duplicate
media streams encryption, such as IP Call Recording.
Note 3: It takes as a few seconds at the beginning of the call for security
to be established. As a result, the first few seconds of the call can
sometimes be unsecured; once the security icon appears, the call is
secure.
Note 4: SRTP media encryption does not work with codecs which have
small payloads, such as 10ms G.729.
For more information about SRTP, see System Security Management
(NN43001-604).
Features overview
IP Phones Description, Installation, and Operation
Page 499 of 630