ISO standards related to cabling

Answer:
I suppose that you mean “data center”, and yes, the best ISO standard for cabling is ISO/IEC 24764, you can download it from the official site of iso.org: https://www.iso.org/standard/43520.html

Another international standard related to cabling is TIA-942, although it is not a ISO standard.

Regarding overhead or underground, both methods have advantages and disadvantages, and a study is necessary to know what is the best in each case (for example, keep in mind that if the refrigeration system is underground, can be better to cabling overhead).

Anyway, remember that ISO 27001 can also help you, because there are controls related to management of physical and environmental security (for example control A.11.2.3 is about cabling security), and there are many companies that have decided to certify with ISO 27001 their data centers. This article can be interesting for you “ISO 270 01 Case study for data centers: An interview Goran Djoreski” : https://advisera.com/27001academy/blog/2013/10/29/iso-27001-case-study-for-data-centers-an-interview-with-goran-djoreski/

By the way, this article can be also interesting for you “Physical security in ISO 27001: How to protect the secure areas” : https://advisera.com/27001academy/blog/2015/03/23/physical-security-in-iso-27001-how-to-protect-the-secure-areas/

And finally, if you are interested in ISO 27001, maybe can be also interesting for you our online course “ISO 27001:2013 Foundations Course” : https://advisera.com/training/iso-27001-foundations-course/