Multi lane optics

Tyler Conrad tyler at
Tue Dec 19 16:45:30 CST 2017

This blog has a pretty good runthrough -

Scroll down to "100G PROTOCOLS".

On Tue, Dec 19, 2017 at 8:38 AM, Baldur Norddahl <baldur.norddahl at>

> 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

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