@@ -461,9 +461,47 @@ Physical network interfaces require device drivers to make use of the physical h
The device driver often needs elevated privileges to read and write memory. Device drivers for physical network interfaces often must have access also to the network interface control registers, directly or via host memory address space mapped to them; sometimes device drivers must as well enable or disable interrupts or other host hardware functions. This usually requires that the device driver has a high level of privilege on the host system.
## 4.4 Operational Environment
## 4.3 Operational Environment
A network interface operates in the context of a host system and a network which may include other products. If the device driver is not included with the product, it will be provided by the operating system or other part of the system.
<mark>Editor’s Note: This clause should describe the conditions under which products of a particular type in the category are used as well as detailing possible systems in which they are integrated, including network context, integration environment, and physical surroundings, including the external conditions affecting RDPS.</mark>
<mark>Editor’s Note: Human factors of the operational environment are to be discussed in other clauses.</mark>
### 4.3.1 General description
A network interface in use for its intended purpose is integrated into a host system and attached to a network.
### 4.3.2 Physical/Hardware environment
A physical network interface is attached to a host by a system bus, and the network by a transmission media adapter. Other products may also have access to the system bus or the network.
A physical network interface may have access to host system assets via the system bus.
The system bus and transmission media adapter of a physical network interface may be physically accessible to untrusted users.
A physical network interface will vary in ease of removal from the host system.
### 4.3.3 Logical/Software environment
The host system make use of the physical or virtual network interface via host software, most often an operating system that implements a network stack.
The host system typically uses the functions of a physical network interface through a device driver. If the device driver is not included with the product, it will be provided by the operating system or other part of the system.
A virtual network interface does not require a separate device driver.
Untrusted agents may be able to run unprivileged software on the host system.
The hardware and software on the product and any associated device driver will range in complexity depending on the number and type of features implemented.
The sensitivity of the data stored on and transmitted by the host system will vary, as will the functions of the host system.
### 4.3.4 Connectivity aspects
A network interface is attached to a network which may be accessible by other products attached to the network.
A physical network interface is attached to a host system bus which may be accessible by other products attached to the system bus.
The attached network may be an isolated private network, a private network with a filtered connection to a public network, or a public network directly accessible by many untrusted agents.
