I we see random unregistrations, I enabled more debug logging, I see this.

XML Received for Invoke ID 9999: <?xml version="1.0" encoding="UTF-8"?>
<TerminalUnregisteredEvent xmlns="http://www.avaya.com/csta"><ns1:monitorCrossRefID xmlns:ns1="http://www.ecma-international.org/standards/ecma-323/csta/ed3">221</ns1:monitorCrossRefID><device><ns2:deviceIdentifier xmlns:ns2="http://www.ecma-international.org/standards/ecma-323/csta/ed3" typeOfNumber="other" mediaClass="voice" bitRate="constant">341:ProcrCMMain:192.168.11.5:1</ns2:deviceIdentifier></device><reason>CM Connection lost - sockets closed due to Exception:End of stream from DefaultTCPChannel Bound to SocketAddress: /192.168.11.14:23264 Connected to SocketAddress: /192.168.11.5:1720</reason><code>-3</code></TerminalUnregisteredEvent>


Unexpected (AES) - Terminal Unregistered for Extension 341, Cross Ref ID: 221, Code: -3, Reason: CM Connection lost - sockets closed due to Exception:End of stream from DefaultTCPChannel Bound to
SocketAddress: /192.168.11.14:23264 Connected to SocketAddress: /192.168.11.5:1720

what could be the reason for this?

Thank you,

Frank

It looks like the connection was lost to the Communication Manager. If only one terminal is unregistered and others are still OK, it may be that the Communication Manager unregistered the terminal for some reason.

You would need to examine the traces on the AE Services to try to get more information.

Martin