# Restrictions (/docs/settings/mqtt/restrictions)



The settings below are modelled after HiveMQ client library's documentation for
[connect#restrictions](https://hivemq.github.io/hivemq-mqtt-client/docs/mqtt-operations/connect/#restrictions).

### 1. Receive Maximum [#1-receive-maximum]

Maximum number of MQTT messages the client can receive simultaneously.

**Default:** 65535

### 2. Send Maximum [#2-send-maximum]

Maximum number of MQTT messages the client can send simultaneously.

**Default:** 65535

### 3. Maximum Packet Size [#3-maximum-packet-size]

Maximum size in bytes of MQTT packets the client can receive.

**Default:** 268435460

### 4. Send Maximum Packet Size [#4-send-maximum-packet-size]

Maximum size in bytes of MQTT packets the client can send.

**Default:** 268435460

### 5. Topic Alias Maximum [#5-topic-alias-maximum]

Maximum number of topic aliases the client can receive.

**Default:** 0

### 6. Send Topic Alias Maximum [#6-send-topic-alias-maximum]

Maximum number of topic aliases the client can send.

**Default:** 16

### 7. Request Problem Information [#7-request-problem-information]

When enabled, the client requests additional problem information
from the broker in MQTT responses.

**Default:** true

### 8. Request Response Information [#8-request-response-information]

When enabled, the client requests additional response information
from the broker in MQTT responses.

**Default:** false