Block-switched Networks: A New Paradigm for Wireless Transport Offense Alok Rakkhit and Patrick Wong

Hop and the Link Layer Designed for wireless link-layer protocols specifically Designed for wireless link-layer protocols specifically How will it work over other LL protocols? How will it work over other LL protocols? Replace Hop with TCP/UDP under wired protocols? Replace Hop with TCP/UDP under wired protocols? If LL bursts behave differently, will there still be performance gains? If LL bursts behave differently, will there still be performance gains?

Hop and the Network Stack Breaks hierarchy by skipping over network layer and directly interacting with link layer Breaks hierarchy by skipping over network layer and directly interacting with link layer How will issues at IP layer affect Hop How will issues at IP layer affect Hop Never explicitly stated Never explicitly stated At every hop a packet packets have to be processed down to the transport layer instead of the link layer At every hop a packet packets have to be processed down to the transport layer instead of the link layer Implemented over UDP, making it a second Transport Layer? Implemented over UDP, making it a second Transport Layer? Are the comparisons representative? Are the comparisons representative?

Caching Makes heavy use of caching at each router Makes heavy use of caching at each router When there is lots of traffic won’t there be issues with the caches filling up? When there is lots of traffic won’t there be issues with the caches filling up?

Performance gains Not clear whether the performance is due to Hop itself or the underlying routing protocol Not clear whether the performance is due to Hop itself or the underlying routing protocol “In conjunction with a disruption-tolerant routing protocol…” it does well “In conjunction with a disruption-tolerant routing protocol…” it does well

Experiment Why b? Why not conduct all the experiments on g instead of shoving that as a sub-experiment? Why b? Why not conduct all the experiments on g instead of shoving that as a sub-experiment? Table 1: Median and mean improvements are so different. Some of the means are just 1x = no improvement! Table 1: Median and mean improvements are so different. Some of the means are just 1x = no improvement! Multiple researches on TCP modifications for multi-hop networks. Multiple researches on TCP modifications for multi-hop networks. Would have been nice to compare those instead Would have been nice to compare those instead Makes a stronger argument that Hop is *fundamentally* better Makes a stronger argument that Hop is *fundamentally* better

Conclusion Not easily deployable Not easily deployable Paper does not conclusively prove Hop is fundamentally better than TCP Paper does not conclusively prove Hop is fundamentally better than TCP