To OOB, or Not to OOB?: Why Out-of-Band Communications…

**Out-of-band (OOB) communications are alternative, independent channels to support incident response when normal systems are unavailable or untrustworthy.** The guidance outlines when to use OOB, required capabilities (email, real-time chat, voice, mass one-way messaging, file storage, external sites), legal and security considerations, the importance of limiting access to responders, and the need to provision and regularly test OOB solutions before incidents occur.