Re: drop all fragments inside tx queue if one gets dropped

2016-04-21 Thread Michael Richardson
Rick Jones wrote: > I don't recall seeing similar poor behaviour in Linux; I would have > assumed > that the intra-stack flow-control "took care" of it. Perhaps there is > something specific to wpan which precludes that? The major user of big UDP packets in

Re: drop all fragments inside tx queue if one gets dropped

2016-04-20 Thread Rick Jones
For the "everything old is new again" files, back in the 1990s, it was noticed that on the likes of a netperf UDP_STREAM test on HP-UX, with fragmentation taking place, it was possible to consume 100% of the link bandwidth and have 0% effective throughput because the transmit queue was kept

Re: drop all fragments inside tx queue if one gets dropped

2016-04-20 Thread Michael Richardson
{adding some more comments from the -wpan side of things} Alexander Aring wrote: > On linux-wpan we had a discussion about setting the right tx_queue_len > and came to some issues in 802.15.4 6LoWPAN networks. ... > And then a lot of fragments laying inside

drop all fragments inside tx queue if one gets dropped

2016-04-20 Thread Alexander Aring
Hi, On linux-wpan we had a discussion about setting the right tx_queue_len and came to some issues in 802.15.4 6LoWPAN networks. Our hardware parameters are: - Bandwidth: 250kb/s - One framebuffer at hardware side for transmit a frame. - MTU - 127 bytes (without mac headers) To provide