North American Network Operators Group Date Prev | Date Next | Date Index | Thread Index | Author Index | Historical Re: Questions about Internet Packet Losses
> Isn't it unsurpsrising that >40% of packets are small? ACKs? > > If one made the gross oversimplifying approximation that everything is > unidirectional TCP traffic, then you'd expect to see one ACK per two data > packets. This is actually not at all a gross oversimplying approximation. Much TCP traffic unidirectional or request/response. The latter looks a whole lot like two back-to-back unidirectional connections, with only one chance to piggyback acks at the switchover. > Thus, we'd expect to see 33% at 40 bytes. It is the additional > 7+% that's surprising. Throw in frequent SYN/FIN/RST's because of small Web connections, SYN retransmissions because busy Web servers have full listen queues (or are being SYN-flooded :-), TCP's that ack every packet (Linux 1.0, I believe, and maybe later ones), TCP's that wind up acking every packet because their delay timer is less than an MSS prop time across a slow link (Solaris, for links < 10KB/sec), and dup acks due to sequence holes, and you might handwave the 7%. Vern - - - - - - - - - - - - - - - - -
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