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The recommend settings is 100kbps both upload and download per user. E.g. if you have 10 users we recommend reserving 1Mbps in each direction

What is SIP ALG?

SIP ALG, or Session Initiation Protocol Application Layer Gateway, is a tool that some networks use to speed along SIP requests to initiate connections.

This tool involves rewriting the packet headers of SIP requests that pass through the router out to the internet. For some services, this tool may be useful.

Still, for many VoIP providers, the rewritten SIP packet header strips out information that is necessary to securely authorize the device making the connection.

More importantly, it responds directly to the device that is requesting the connection. This feature can lead to some of the most common issues that customers have with VoIP — phones losing connection, dropped calls, and one-way audio.

SIP ALG modifies SIP packets in unexpected ways, corrupting them and making them unreadable. This can give you unexpected behaviour, such as phones not registering and incoming calls failing. Therefore if you are experiencing problems we recommend that you check your router settings and turn SIP ALG off if it is enabled.