ISM-1100 ASD Information Security Manual (ISM)

Terminating TOP SECRET Cables in Cabinets

TOP SECRET cables must be connected only in designated TOP SECRET cabinets for security purposes.

Preventative TOP SECRET ASD Information Security Manual Guidelines for communications infrastructure Cabling security Secure facilities

🏛️ Framework

ASD Information Security Manual (ISM)

🧭 Control effect

Preventative

🔐 Classifications

🗓️ ISM last updated

Aug 2018

✏️ Control Stack last updated

22 Feb 2026

🎯 E8 maturity levels

N/A

Guideline

Guidelines for communications infrastructure

Section

Cabling infrastructure

Topic

Terminating Cables in Cabinets

Official control statement

TOP SECRET cables are terminated in an individual TOP SECRET cabinet.

Source: ASD Information Security Manual (ISM)

Plain language

This control means that any cables carrying highly classified information, labelled as TOP SECRET, should only be hooked up in cabinets specifically designed for such sensitive data. This is crucial because if these cables are connected in an improper place, it increases the risk of this very sensitive information being accessed by unauthorised people, leading to national security concerns.

Why it matters

Improperly terminated TOP SECRET cables risk unauthorised access, potentially leading to critical national security breaches.

Operational notes

Verify TOP SECRET cable terminations are only within the individual TOP SECRET cabinet, and inspect cabinets routinely for unauthorised terminations.

Implementation tips

The IT team should identify all the TOP SECRET cables within the organisation. They can do this by reviewing network diagrams and consulting with key staff who manage classified information.
Facility managers should work with the IT team to designate specific cabinets as TOP SECRET cabinets. This involves setting aside secure locations and labelling them clearly as only for TOP SECRET cables.
An IT manager should oversee the installation of the TOP SECRET cables in these designated cabinets. This means ensuring only authorised staff with the right security clearance perform the installation.
Security officers should ensure regular checks are done to verify that the TOP SECRET cables remain within their designated cabinets. This can be done monthly through physical inspections and comparing against the network layout.
Staff responsible for handling these cables should receive training on the procedures for managing TOP SECRET cables. This training should cover how to properly terminate cables and the importance of maintaining their secrecy within the designated cabinets.

Audit / evidence tips

Ask: the list of designated TOP SECRET cabinets within the facility

Good: is a dated document listing each cabinet's location with a security officer's approval
Good: is a list showing clearance levels and dates of training completed
Ask: recent inspection reports of the TOP SECRET cabinets. Verify that these reports were conducted routinely as per the policy and document any findings or non-compliance

Good: includes signed inspection logs
Good: includes up-to-date certificates of completion with specified training content
Ask: the policy document that outlines the procedures for terminating TOP SECRET cables

Good: is a policy document with specific procedures and a last review date

Cross-framework mappings

How ISM-1100 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 (1)
Annex A 7.12	ISM-1100 requires TOP SECRET cables to be terminated only within an individual TOP SECRET cabinet, which specifies a precise location for...