What is QoS in MQTT publish?

The Quality of Service (QoS) level is an agreement between the sender of a message and the receiver of a message that defines the guarantee of delivery for a specific message. There are 3 QoS levels in MQTT: At most once (0) At least once (1) Exactly once (2).

What is latency MQTT?

Devices, for example sensors, energy meters, pace makers etc are ideal use cases for MQTT. Low latency means high speed. For low latency you require different protocol, like Reliable Multicast running over Gigabit Ethernet or InfiniBand networks.

How does MQTT work?

MQTT is a publish/subscribe protocol that allows edge-of-network devices to publish to a broker. Clients connect to this broker, which then mediates communication between the two devices. When another client publishes a message on a subscribed topic, the broker forwards the message to any client that has subscribed.

Why is qos1 better than QoS 2?

If you really need to make sure that a message arrives once and only once, you can use QoS 2. QoS 1 means that your clients can handle duplicates (either by ignoring a duplicate message or the messages are idempotent).

How many clients can Mosquitto handle?

To achieve greater than one million concurrent connections we deployed 6 message brokers each can handle 200k simultaneous connections. These brokers are again interconnected using DMR. This enables us to assure that our platform has a capability to handle greater than 1 million concurrent connections.

How reliable is MQTT?

Reliability of MQTT MQTT can allow for messages to be stored at the broker until a device is ready to receive it. Thanks to QoS (Quality of Service), MQTT has the ability to queue messages, make sure they get where they are going and if required, ensure that they only get there once.

Does MQTT retain?

A retained message is a normal MQTT message with the retained flag set to true. Each client that subscribes to a topic pattern that matches the topic of the retained message receives the retained message immediately after they subscribe. The broker stores only one retained message per topic.

Does QoS affect download speed?

With regard to your case, the speed will cut in half because the Downstream QoS is enabled on your router. It will allocate the half of the speed to Video Streaming since the Downstream if for Video Streaming.