SurgeX SX-AX20E - Manual (Page 26)

Axess Elite User Manual
Firmware Version v1.06.227
© SurgeX | Technical Support: 800-645-9721 | surgex.com
9. SDxP Protocol
9.1 Overview
The SDxP Protocol is a packet-based protocol designed to be extensible. This protocol is transmitted over TCP
on a user-defined port. The factory default SDxP port is 9100.
The protocol uses a Hello handshake to establish unique sequence numbers to allow for advanced security when
AES encryption is used. With AES enabled, all messages must be encrypted with the AES Passphrase set in the
device.
After the Hello, a Command and Response sequence follows. Any number of
Command → Response sequences are permitted after Hello.
9.2 Hello Handshake
The client sends a Hello message in the form of a text string “hello-000”. The SDxP enabled Axess Elite will
respond with a packet containing the unsigned 16 bit sequence number. This sequence number is incremented
by the client and server with each correct packet sent.
Example:
Client Server
hello-000 →
←
1234
(seq 1234)
Command →
(seq 1235)
← Response
Command →
(seq 1237)
← Response