What happens if I only add some of required public SIP IP addresses for BYOC Cloud to my allowlist?

The BYOC Cloud public SIP IP addresses article specifies that you must add all four of available public SIP IP addresses for your organizations region to your allowlist. If you only add some of them, you will encounter failed call attempts.

For example, if you only add two of the four IP addresses to your allowlist, roughly half of your call attempts will fail.