In this paper, we pose a question of wether the request on path optimality is necesary in Ethernet-over-optical networks, and set the goal to calculate the upper bounds on differential delay and buffer requirement for Ethernet multilane transmission in a randomly routed optical network. We compare two distict cases applicable to forwarding of multi-lane Ethernet traffic: WDM and optical packet switched networks. In case of WDM, which we refer to as RND-MP, any randomly chosen set of wavelength-routed paths among all available paths can be used for parallel transmission. In the optical packet switched network, referred to as RND-OPS, we assume that paths do not need to be reserved in advance, whereby the forwarding can be hop-by-hop, following a randomly chosen free port at every optical packet switch. The analytical and simulation results are promising and show that, in a heavily loaded network, RND-OPS yields excellent results with comparably low buffer requirement. RND-MP performs better for over-provisioned networks. To the best of our knowledge this is the first analysis to addressing the problem of multipath routing in optical networks without optimizations or complex path computation algorithms.