AT-OCS-900N
32
Device Operation
IMPORTANT:
Authentication credentials are not automatically encrypted when transmitted to
the broker, making the information vulnerable to a MITM attack. It is highly recommended to
use Transport Layer Security (TLS) when connecting to a broker. Refer to
for more information.
QoS Setting
Description
0
At most once
- Guarantees a best-effort delivery. It functions similar
to the UDP protocol, where there is no guarantee of delivery from the
client to the broker. The recipient does not acknowledge receipt of
the message and the message is not stored and re-transmitted by the
sender.
1
At least once
- Guarantees that a message is delivered at least once
to the receiver. The sender stores the message until it receives a
PUBACK
packet from the receiver that acknowledges receipt of the
message.
2
Exactly once
- The highest level of service and guarantees that
each message is received only once by the intended recipients. The
guarantee is provided by at least two request/responses between the
sender and the receiver.
6. Under
Authentication Settings
do the following:
a. Enter the required information in the
Username
and
Password
fields. When a client connects to a
broker, both the user name and password are included in the
CONNECT
message for authentication
purposes. It should be noted that authentication is optional and only required if the broker requires
authentication.
b. To enable authentication, click the
Authentication
checkbox. When a checkmark is in this box, the
feature is enabled.
7. Under
Last Will Settings
do the following:
a. Enter the
Last Will and Testament
(LWT)
topic in this
Topic
field. This topic is sent to other clients when a
client does not disconnect gracefully. An example topic might be
/client1/status
.
b. Click the
QoS
field to select the desired Quality of Service setting.
c. Enter the message in the
Message
field.