Avaya CS 1000E Upgrade Procedures page 199

Installing a Signaling Server Page 199 of 226
When a device joins the UCM security domain, a mutually-trusted SSH
channel is created. You must manually confirm the fingerprint of the public
key before the UCM Primary Security Server RSA public key is added to the
authorized key file, . This verification prevents third-party intercepts.
When a mutually-trusted SSH tunnel establishes a connection to a CS 1000
device, the UCM Primary Security Server can send SSH remote commands
to the device using RSA public key-based authentication.
For more information about joining the UCM security domain, see Security
Management Fundamentals (NN43001-604).
Avaya Communication Server 1000E Upgrade Hardware Upgrade Procedures