Reading on "Scaling Internet Routers Using Optics"

Summary: this paper presents a new router architecture whose switching capacity is 100TB/s. The authors extended Chang's  load-balanced router architecture using optical devices. In order to avoid N*N fibers, the authors suggested to use ASGR which only uses 2N fibers. FOFF(Full Ordered Frames First) is presented to solve the packet mis-sequencing problem. The authors predicted the techniques in three years and discussed some difficult issues to make the the new router practical.

Background: understanding on Chang's load-balanced router architecture;

Discussion: I have lots of problems to understand this paper. I have to admit i don't truly understand the idea of this paper.

1, Is FOFF a good idea to guarantee the packets in sequence? my intuition is that this idea is too simple to let the authors be the first one to have this idea. Meanwhile, even bringing N*N+1 buffers to the linecard is not an issue, how about the delay?

2, I am wandering how to prove the interconnection of M*G*M is equal to N*N. I feel totally lost about the "bit-slicing". What is this? Introduce another smaller 3-stage router per linecard?

3, How about the router's practicality facing on the IPv6? Unbelievable, the author discussed the future router without IPv6?

4, Why let M equals G+L-1 can eliminate the imbalance? Maybe i am too stupid to understand the simplest example?

5, Last but not least, the authors didn't convince me about without central switching fabric configuration,  the router can work correctly. 

I have read this paper throughly twice. So sad to have so many questions.