memcache

When laeproxy forwards a range request to a server that doesn't support them, it converts any 200 response it gets back into a 206 if possible, and just discards the portion of the response outside the requested range. laeproxy should cache this portion for future requests if possible, as recommended by http://tools.ietf.org/html/rfc2616#section-14.35.2 (last paragraph).
