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ISM-1019 ASD Information Security Manual (ISM)

Develop a Denial of Service Response Plan

Create and maintain a plan to handle service disruptions for video calls and IP telephony.

🏛️ Framework

ASD Information Security Manual (ISM)

🧭 Control effect

Proactive

🔐 Classifications

NC, OS, P, S, TS

🗓️ ISM last updated

Nov 2022

✏️ Control Stack last updated

19 Mar 2026

🎯 E8 maturity levels

N/A

Official control statement
A denial of service response plan for video conferencing and IP telephony services is developed, implemented and maintained.

Source: ASD Information Security Manual (ISM)

Plain language

Imagine you're having a team video call or trying to make a phone call over the internet, and suddenly, it's impossible because of a problem blocking the service. This control ensures that you have a plan to quickly and effectively handle such disruptions so your business can continue running smoothly and not lose valuable time or client trust.

Why it matters

Without a DoS response plan, attacks can disrupt video conferencing and IP telephony, preventing calls/meetings and delaying incident coordination.

Operational notes

Exercise the DoS plan for VTC/SIP outages, including ISP/provider escalation, traffic filtering/rate-limits, failover routing, and comms to users.

Implementation tips

  • The IT manager should work with team leads to develop a response plan targeting video conferencing and IP telephony disruptions. Start by identifying critical communication systems and brainstorming potential issues that could cause downtime, like internet outages or software glitches.
  • Schedule regular training sessions: The IT team should hold workshops for staff on how to recognise when a service issue might be happening and who to notify. Use real-world scenarios to practise response steps, ensuring everyone knows their role in the plan.
  • Create a clear communication protocol: The IT manager needs to set up a notification system that updates all employees when downtime occurs. This can be achieved by setting up group emails or a messaging platform to provide timely information and updates.
  • Assign specific roles: Assign team members to handle different tasks during a service outage, ensuring that everyone knows their specific responsibility. Write down these roles and tasks in a document or shared online folder accessible to the team.
  • Conduct regular testing: IT staff should perform scheduled simulations to test the response plan's effectiveness. This can include mock scenarios where services are deliberately disrupted, ensuring the team can respond quickly and make any necessary adjustments to the plan.

Audit / evidence tips

  • Ask: the written summary of the denial of service response plan: Request the current document that details the procedures for dealing with video conferencing and IP telephony disruptions

    Good: shows clear, actionable steps for all involved parties and regularly updated contact details

  • Ask: to see training records: Request a log or documentation of training sessions conducted with staff on handling service disruptions

  • Good: displays efficient use of communication tools to keep all staff informed

  • Ask: to view files or reports documenting the testing of the response plan. Inspect whether these reports detail the scenarios tested, results, and any improvements made

    Good: provides evidence of regular testing and a commitment to refining the response approach

  • Good: has detailed descriptions and names easily understood by reviewing parties

Cross-framework mappings

How ISM-1019 relates to controls across ISO/IEC 27001, Essential Eight, and ASD ISM.

These mappings show relationships between controls across frameworks. They do not imply full equivalence or certification.

ISO 27001

Control Notes Details
Partially meets (2)
Annex A 5.24 ISM-1019 requires a maintained DoS response plan for specific services to handle availability disruptions
Annex A 5.30 ISM-1019 requires a documented and maintained DoS response plan for video conferencing and IP telephony services
Supports (1)
Annex A 5.28 ISM-1019 focuses on developing a DoS response plan for specific services

E8

Control Notes Details
Partially meets (2)
E8-MF-ML2.12 ISM-1019 requires an organisation to develop, implement and maintain a DoS response plan specifically for video conferencing and IP telep...
E8-RA-ML2.13 ISM-1019 creates a DoS response plan for video conferencing and IP telephony services

Mapping detail

Mapping

Direction

Controls