The telecommunications industry is a world all its own. For example, (in the United States, at least) the telecom standard color code for DC power wires says negative is red and positive is black, when the rest of the world uses red for positive and black for negative. This can be quite shocking to an engineer coming from the consumer or automotive electronics industry.
Cooling electronics in the telecom world has certain unique quirks as well. The thermal design challenges are not so much driven by extremes of power dissipation, crazy environments or even cost, as they are overshadowed by the need for the phone network to never, ever stop working. Reliability, availability, repairability and redundancy drive everything. If you need one fan to cool your circuit, then you probably need two. But having two creates potential leaks if one dies, so then you probably need four. And just in case, better make it six, or even eight.