Vivox: What causes VxXmppServerErrorServiceUnavailable (20502) errors?

VxXmppServerErrorServiceUnavailable (20502) errors can occur in three scenarios:

• Mixing channel types
• Joining more than 10 channels
• Having more than 200 users in a non-positional channel

Scenario 1

This error can occur if you mix types of channels. This applies in the following scenarios:

• Joining an echo channel when in a positional or non-positional channel
• Joining a non-positional or positional channel when in an echo channel
• Joining a second positional channel

This error does not occur in the following scenarios:

• Joining a non-positional channel when in a positional channel
• Joining a non-positional channel when in another non-positional channel

Refer to the following guidelines to avoid this error:

• Echo channels must be alone.
• Do not join other channels when in an echo channel.
• Do not try to join other channels when in an echo channel.
• Only join one positional channel.

Scenario 2

This error can occur if a single user tries to join an 11th non-positional channel. Users are allowed to be in 10 non-positional channels and one positional channel at the same time.

A non-positional channel is considered an audio and/or text channel, and does not use the positional functionality. For example:

• A text-only channel is one channel
• An audio-only channel is one channel
• A channel that is using both text and audio is one channel

To avoid this error, ensure that users are only joined to 10 or fewer channels.

Scenario 3

If 200 users are already in a channel, the 201st user that tries to join the channel could encounter this error.

To avoid this error, follow the recommendations in How to: Monitor channel size for large-scale channels.