Step 2: NT Proxy Function After the TLP hits BAR 2 an ID translation also takes place. This ID translation is used to convert the BDF (Bus/Device/Function) of the TLP jumping partitions into the BDF of a Non-Transparent proxy function. This proxy function allows the TLP to look like it originated within the destination partition. It also allows the completion TLP coming back to translate its BDF back to the original BDF and find its way back to the source partition. If we look at the original TLP it has a requester ID of 0.1.0. The ID translation translates the device and function numbers of the BDF to match the device and function of the proxy function. The bus number is not changed because the ID translation does not know the bus number of the proxy function at this point. The value of requester ID ends up being 0.31.7. The 31 is the device number of the proxy function and 7 is the function number.

在第二步中，当TLP命中BAR 2时还会进行ID转换。该ID转换用于将跨越分区的TLP的BDF（总线/设备/功能）转换为非透明代理功能的BDF。这个代理功能使得TLP看起来像是在目标分区内发起的。它还允许返回的完成TLP将其BDF转换回原始BDF，并找回到源分区。

如果我们看一下原始的TLP，它的请求者ID是0.1.0。ID转换将BDF的设备和功能号码转换为与代理功能的设备和功能号码匹配。总线号没有改变，因为此时ID转换不知道代理功能的总线号。请求者ID的值最终变为0.31.7。31是代理函数的设备号，7是功能号。