I am learning about 40Gbps QSFP; however, it says channels, and 4x 10Gbps channels. Does this mean that it is a type of Port-channel or load balancing and where each session or stream is only going to get 10Gbps?
I need to connect a 2k to a 5k, which I have options to use QSFP or SFP+. I am just not sure how the 40Gbps is true 40Gbps with 4x 10Gbps links.
I believe (?) the way it works if you have the QSFP on both ends it uses the 4 10g links like an IMUX. I.e. you should be able to send even a single flow at 40g.
I also believe (?) of the QSFP modules support 10g breakout, i.e. they can connect to "ordinary" 10g ports on the other side. In such cases, the QSFP would appear to be 4 10g links. (The advantage of this would be port density on the QSFP side.)
BTW, I'm not an expert in optics, but I see no one else has tried to answer your question, yet.
Not an optics expert myself either but I have setup 40g as 4x10g and in such case they are four independent 10g interfaces with no relationship to each other.
If you use it as 1x40g then thats what you get 40g of traffic. Internally it does some multiplexing to achieve 40G but this is transparent to you, its not a port channel neither do you need to configure anything related to port channel