Layers outside of OSI Model:

[abbas.ali]

Can someone shed some lights on the layer below.  The OSI Model only  covers seven layers, and am just trying to understand where the layers  below are used.

Development Environment Layer

Testing Layer

Infrastructure Layer

Thanks

[Leo Laohoo]

Development Environment Layer

Infrastructure Layer

They're not OSI, they're the counterpart, the ISO.  Mostly seen in x.25 protocols.

[abbas.ali]

Thanks Leo

Is there any site where I can find description of these layers.  I tried google, but no luck

[Leo Laohoo]

My response contains HTML link.