Multi lane optics

[baldur.norddahl at gmail.com (Baldur Norddahl)]

Hello,

Some optics are implemented with multiple lasers such as QSFP+ with 4x 
10G = 40G or QSFP28 with 4x 25G = 100G. How is the ethernet traffic load 
balanced between those lanes? Is it bit by bit or more like LACP (packet 
by packet)?

I need to make sure my solution will handle 10G streams correctly. We 
have a problem with N x 10G and LACP because our L2VPN MPLS endpoints 
are lacking the flow label support. If I sell a 10G circuit to a 
customer and uses a L2VPN to transport his port, everything may go on 
the same sub channel. LACP will not load balance correctly, because it 
only sees the outer MAC address for hashing, which is the same for all 
packets.

Now we are worried that multi lane optics might have the exact same problem.

Regards,

Baldur