DNS SRV Compatibility with Asterisk 11

I am wanting to do some tinkering with DNS SRV and was curious if this works with Asterisk 11.

I have a primary PBX, PBX-A and a warm spare PBX, PBX-B that is configured to mirror PBX-A.

The thought would be that my clients would have their endpoints registered to PBX-A, in the event that it goes down or becomes unavailable, their endpoints would stay registered and calls would automatically route through PBX-B using DNS SRV records.

Is this possible in Asterisk 11?

Thank you!

Yup. Enable SRV Lookups is an option in the Asterisk SIP Settings for Chan_SIP. You need to enable it so Asterisk will add the SRV prefix to lookups.