Look at the architecture of the router and the memory constraints. On most architectures a node process starts around 10mb of ram. I know v8 builds on linux on i686, x64, and most arm variants. There is some mips support as well.
Depending on what you're trying to do, raw libuv with C may be better. It has fewer requirements and uses a lot less memory. The API is somewhat close to node's since it provides most of nodes system primitives. Also I made lua bindings for libuv (
luvit.io) that expose a node-like API. The lua vm is slimmer than v8, but still much more bloated than just using C.